Losartan potassium and Hydrochlorothiazide

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# Black Box Warning

# Overview
Losartan potassium and Hydrochlorothiazide is an antihypertensive agent that is FDA approved for the treatment of hypertension. There is a Black Box Warning for this drug as shown here.  Common adverse reactions include electrolytes abnormal, backache, dizziness, upper respiratory infection.

# Adult Indications and Dosage

## FDA-Labeled Indications and Dosage (Adult)
- Losartan Potassium and Hydrochlorothiazide Tablets are indicated for the treatment of hypertension. This fixed dose combination is not indicated for initial therapy of hypertension, except when the hypertension is severe enough that the value of achieving prompt blood pressure control exceeds the risk of initiating combination therapy in these patients.
Hypertensive Patients with Left Ventricular Hypertrophy
- Losartan Potassium and Hydrochlorothiazide Tablets are indicated to reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients.
- Dosing Information:
- Dosing must be individualized. The usual starting dose of losartan is 50 mg once daily, with 25 mg recommended for patients with intravascular volume depletion (e.g., patients treated with diuretics) and patients with a history of hepatic impairment. Losartan can be administered once or twice daily at total daily doses of 25 to 100 mg. If the antihypertensive effect measured at trough using once-a-day dosing is inadequate, a twice-a-day regimen at the same total daily dose or an increase in dose may give a more satisfactory response.
- Hydrochlorothiazide is effective in doses of 12.5 to 50 mg once daily and can be given at doses of 12.5 to 25 mg as Losartan Potassium and Hydrochlorothiazide Tablets.
- To minimize dose-independent side effects, it is usually appropriate to begin combination therapy only after a patient has failed to achieve the desired effect with monotherapy.
- The side effects (see WARNINGS) of losartan are generally rare and apparently independent of dose; those of hydrochlorothiazide are a mixture of dose-dependent (primarily hypokalemia) and dose-independent phenomena (e.g., pancreatitis), the former much more common than the latter. Therapy with any combination of losartan and hydrochlorothiazide will be associated with both sets of dose-independent side effects.
- Replacement Therapy: The combination may be substituted for the titrated components.
- Dose Titration by Clinical Effect: A patient whose blood pressure is not adequately controlled with losartan monotherapy (see above) or hydrochlorothiazide alone, may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily. If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily. A patient whose blood pressure is not adequately controlled with losartan 100 mg monotherapy (see above) may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/12.5 mg once daily. If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
- A patient whose blood pressure is inadequately controlled by 25 mg once daily of hydrochlorothiazide, or is controlled but who experiences hypokalemia with this regimen, may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily, reducing the dose of hydrochlorothiazide without reducing the overall expected antihypertensive response. The clinical response to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg should be subsequently evaluated, and if blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
- The usual dose of Losartan Potassium and Hydrochlorothiazide is one tablet of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily. More than two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or more than one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily is not recommended. The maximal antihypertensive effect is attained about 3 weeks after initiation of therapy.
- Use in Patients with Renal Impairment: The usual regimens of therapy with Losartan Potassium and Hydrochlorothiazide Tablets may be followed as long as the patient's creatinine clearance is >30 mL/min. In patients with more severe renal impairment, loop diuretics are preferred to thiazides, so Losartan Potassium and Hydrochlorothiazide Tablets are not recommended.
- Patients with Hepatic Impairment: Losartan Potassium and Hydrochlorothiazide Tablets are not recommended for titration in patients with hepatic impairment because the appropriate 25 mg starting dose of losartan cannot be given.
Severe Hypertension
- The starting dose of Losartan Potassium and Hydrochlorothiazide Tablets for initial treatment of severe hypertension is one tablet of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily. For patients who do not respond adequately to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg after 2 to 4 weeks of therapy, the dosage may be increased to one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily. The maximum dose is one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily. Losartan Potassium and Hydrochlorothiazide Tablets are not recommended as initial therapy in patients with hepatic impairment (see WARNINGS, Impaired Hepatic Function) because the appropriate 25 mg starting dose of losartan cannot be given. It is also not recommended for use as initial therapy in patients with intravascular volume depletion (e.g., patients treated with diuretics, see WARNINGS, Hypotension  Volume-Depleted Patients).
Hypertensive Patients with Left Ventricular Hypertrophy
- Treatment should be initiated with losartan potassium tablets 50 mg once daily. Hydrochlorothiazide 12.5 mg should be added or Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg substituted if the blood pressure reduction is inadequate. If additional blood pressure reduction is needed, losartan potassium tablets 100 mg and hydrochlorothiazide 12.5 mg or Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/12.5 mg may be substituted, followed by losartan potassium tablets 100 mg and hydrochlorothiazide 25 mg or Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/25 mg. For further blood pressure reduction other antihypertensives should be added.
- Losartan Potassium and Hydrochlorothiazide Tablets may be administered with other antihypertensive agents.
- Losartan Potassium and Hydrochlorothiazide Tablets may be administered with or without food.
- Dosing Information
- Initial, losartan 50 mg ORALLY once daily
- Maintenance, 50 mg losartan/12.5 mg hydrochlorothiazide ORALLY once daily; may increase to 100 mg losartan/25 mg hydrochlorothiazide once daily to control blood pressure

## Off-Label Use and Dosage (Adult)

### Guideline-Supported Use
- Postoperative cardiac complication, Noncardiac surgery; Prophylaxis

# Pediatric Indications and Dosage

## FDA-Labeled Indications and Dosage (Pediatric)
- There is limited information regarding FDA-Labeled Use of Losartan potassium and Hydrochlorothiazide in pediatric patients.

## Off-Label Use and Dosage (Pediatric)

### Guideline-Supported Use
- There is limited information regarding Off-Label Guideline-Supported Use of Losartan potassium and Hydrochlorothiazide in pediatric patients.

### NonGuideline-Supported Use
- There is limited information regarding Off-Label NonGuideline-Supported Use of Losartan potassium and Hydrochlorothiazide in pediatric patients.

# Contraindications
- Losartan Potassium and Hydrochlorothiazide Tablets are contraindicated in patients who are hypersensitive to any component of this product.
- Because of the hydrochlorothiazide component, this product is contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs.
- Do not co-administer aliskiren with Losartan Potassium and Hydrochlorothiazide Tablets in patients with diabetes.

# Warnings
Fetal Toxicity
Pregnancy Category D
- Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue Losartan Potassium and Hydrochlorothiazide Tablets as soon as possible. These adverse outcomes are usually associated with the use of these drugs in the second and third trimester of pregnancy. Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus.
- In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus. Perform serial ultrasound examinations to assess the intra-amniotic environment.
- If oligohydramnios is observed, discontinue Losartan Potassium and Hydrochlorothiazide Tablets, unless it is considered life-saving for the mother. Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury.
- Closely observe infants with histories of in utero exposure to Losartan Potassium and Hydrochlorothiazide Tablets for hypotension, oliguria, and hyperkalemia (see PRECAUTIONS, Pediatric Use).
- There was no evidence of teratogenicity in rats or rabbits treated with a maximum losartan potassium dose of 10 mg/kg/day in combination with 2.5 mg/kg/day of hydrochlorothiazide. At these dosages, respective exposures (AUCs) of losartan, its active metabolite, and hydrochlorothiazide in rabbits were approximately 5, 1.5, and 1.0 times those achieved in humans with 100 mg losartan in combination with 25 mg hydrochlorothiazide. AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide. Fetal toxicity in rats, as evidenced by a slight increase in supernumerary ribs, was observed when females were treated prior to and throughout gestation with 10 mg/kg/day losartan in combination with 2.5 mg/kg/day hydrochlorothiazide. As also observed in studies with losartan alone, adverse fetal and neonatal effects, including decreased body weight, renal toxicity, and mortality, occurred when pregnant rats were treated during late gestation and/or lactation with 50 mg/kg/day losartan in combination with 12.5 mg/kg/day hydrochlorothiazide. Respective AUCs for losartan, its active metabolite and hydrochlorothiazide at these dosages in rats were approximately 35, 10 and 10 times greater than those achieved in humans with the administration of 100 mg of losartan in combination with 25 mg hydrochlorothiazide. When hydrochlorothiazide was administered without losartan to pregnant mice and rats during their respective periods of major organogenesis, at doses up to 3000 and 1000 mg/kg/day, respectively, there was no evidence of harm to the fetus.
- Thiazides cross the placental barrier and appear in cord blood. There is a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.
- Hypotension - Volume-Depleted Patients
- In patients who are intravascularly volume-depleted (e.g., those treated with diuretics), symptomatic hypotension may occur after initiation of therapy with Losartan Potassium and Hydrochlorothiazide Tablets. This condition should be corrected prior to administration of Losartan Potassium and Hydrochlorothiazide Tablets.
Impaired Hepatic Function
Losartan Potassium and Hydrochlorothiazide
- Losartan Potassium and Hydrochlorothiazide Tablets are not recommended for patients with hepatic impairment who require titration with losartan. The lower starting dose of losartan recommended for use in patients with hepatic impairment cannot be given using Losartan Potassium and Hydrochlorothiazide Tablets.
Hydrochlorothiazide
- Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.
Hypersensitivity Reaction
- Hypersensitivity reactions to hydrochlorothiazide may occur in patients with or without a history of allergy or bronchial asthma, but are more likely in patients with such a history.
Systemic Lupus Erythematosus
- Thiazide diuretics have been reported to cause exacerbation or activation of systemic lupus erythematosus.
Lithium Interaction
- Lithium generally should not be given with thiazides.
Acute Myopia and Secondary Angle-Closure Glaucoma
- Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute transient myopia and acute angle-closure glaucoma. Symptoms include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation. Untreated acute angle-closure glaucoma can lead to permanent vision loss. The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible. Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.
PRECAUTIONS
General
- Hypersensitivity: Angioedema. See ADVERSE REACTIONS, Postmarketing Experience.
- Losartan Potassium and Hydrochlorothiazide
- In double-blind clinical trials of various doses of losartan potassium and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium 5.7 mEq/L) was 0.4%. No patient discontinued due to increases or decreases in serum potassium. The mean decrease in serum potassium in patients treated with various doses of losartan and hydrochlorothiazide was 0.123 mEq/L. In patients treated with various doses of losartan and hydrochlorothiazide, there was also a dose-related decrease in the hypokalemic response to hydrochlorothiazide as the dose of losartan was increased, as well as a dose-related decrease in serum uric acid with increasing doses of losartan.
Hydrochlorothiazide
- Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.
- All patients receiving thiazide therapy should be observed for clinical signs of fluid or electrolyte imbalance: hyponatremia, hypochloremic alkalosis, and hypokalemia. Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids. Warning signs or symptoms of fluid and electrolyte imbalance, irrespective of cause, include dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, confusion, seizures, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.
- hypokalemia may develop, especially with brisk diuresis, when severe cirrhosis is present, or after prolonged therapy.
- Interference with adequate oral electrolyte intake will also contribute to hypokalemia. hypokalemia may cause cardiac arrhythmia and may also sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability).
- Although any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease), chloride replacement may be required in the treatment of metabolic alkalosis.
- Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life-threatening. In actual salt depletion, appropriate replacement is the therapy of choice.
- Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy. Because losartan decreases uric acid, losartan in combination with hydrochlorothiazide attenuates the diuretic-induced hyperuricemia.
- In diabetic patients, dosage adjustments of insulin or oral hypoglycemic agents may be required. Hyperglycemia may occur with thiazide diuretics. Thus latent diabetes mellitus may become manifest during thiazide therapy.
- The antihypertensive effects of the drug may be enhanced in the postsympathectomy patient.
- If progressive renal impairment becomes evident, consider withholding or discontinuing diuretic therapy.
- Thiazides have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.
- Thiazides may decrease urinary calcium excretion. Thiazides may cause intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism. Marked hypercalcemia may be evidence of hidden hyperparathyroidism. Thiazides should be discontinued before carrying out tests for parathyroid function.
- Increases in cholesterol and triglyceride levels may be associated with thiazide diuretic therapy.
Impaired Renal Function
- As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function have been reported in susceptible individuals treated with losartan; in some patients, these changes in renal function were reversible upon discontinuation of therapy.
- In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (e.g., patients with severe congestive heart failure), treatment with angiotensin converting enzyme inhibitors has been associated with oliguria and/or progressive azotemia and (rarely) with acute renal failure and/or death. Similar outcomes have been reported with losartan.
- In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN have been reported. Similar effects have been reported with losartan; in some patients, these effects were reversible upon discontinuation of therapy.
- Thiazides should be used with caution in severe renal disease. In patients with renal disease, thiazides may precipitate azotemia. Cumulative effects of the drug may develop in patients with impaired renal function.

# Adverse Reactions

## Clinical Trials Experience
- Losartan potassium and hydrochlorothiazide has been evaluated for safety in 858 patients treated for essential hypertension and 3889 patients treated for hypertension and left ventricular hypertrophy. In clinical trials with losartan potassium and hydrochlorothiazide, no adverse experiences peculiar to this combination have been observed. Adverse experiences have been limited to those that were reported previously with losartan potassium and/or hydrochlorothiazide. The overall incidence of adverse experiences reported with the combination was comparable to placebo.
- In general, treatment with losartan potassium and hydrochlorothiazide was well tolerated. For the most part, adverse experiences have been mild and transient in nature and have not required discontinuation of therapy. In controlled clinical trials, discontinuation of therapy due to clinical adverse experiences was required in only 2.8% and 2.3% of patients treated with the combination and placebo, respectively.
- In these double-blind controlled clinical trials, the following adverse experiences reported with losartan and hydrochlorothiazide occurred in 1 percent of patients, and more often on drug than placebo, regardless of drug relationship:
- The following adverse events were also reported at a rate of 1% or greater, but were as, or more, common in the placebo group in studies of essential hypertension: asthenia/fatigue, diarrhea, nausea, headache, bronchitis, pharyngitis.
- Adverse events occurred at about the same rates in men and women. Adverse events were somewhat more frequent in the elderly compared to non-elderly patients and somewhat more frequent in Blacks compared to non-Blacks for both the losartan and hydrochlorothiazide and the control groups.
- A patient with known hypersensitivity to aspirin and penicillin, when treated with losartan potassium, was withdrawn from study due to swelling of the lips and eyelids and facial rash, reported as angioedema, which returned to normal 5 days after therapy was discontinued.
- Superficial peeling of palms and hemolysis were reported in one subject treated with losartan potassium.
Losartan Potassium
- Other adverse experiences that have been reported with losartan, without regard to causality, are listed below:
- Body as a Whole: chest pain, facial edema, fever, orthostatic effects, syncope; Cardiovascular: angina pectoris, arrhythmias including atrial fibrillation, sinus bradycardia, tachycardia, ventricular tachycardia and ventricular fibrillation, CVA, hypotension, myocardial infarction, second degree AV block; Digestive: anorexia, constipation, dental pain, dry mouth, dyspepsia, flatulence, gastritis, vomiting; General disorders and administration site conditions: malaise; Hematologic: anemia; Metabolic: gout; Musculoskeletal: arm pain, arthralgia, arthritis, fibromyalgia, hip pain, joint swelling, knee pain, leg pain, muscle cramps, muscle weakness, musculoskeletal pain, myalgia, shoulder pain, stiffness; Nervous System/Psychiatric: anxiety, anxiety disorder, ataxia, confusion, depression, dream abnormality, hypesthesia, insomnia, libido decreased, memory impairment, migraine, nervousness, panic disorder, paresthesia, peripheral neuropathy, sleep disorder, somnolence, tremor, vertigo; Respiratory: dyspnea, epistaxis, nasal congestion, pharyngeal discomfort, respiratory congestion, rhinitis, sinus disorder; Skin: alopecia, dermatitis, dry skin, ecchymosis, erythema, flushing, photosensitivity, pruritus, sweating, urticaria; Special Senses: blurred vision, burning/stinging in the eye, conjunctivitis, decrease in visual acuity, taste perversion, tinnitus; Urogenital: impotence, nocturia, urinary frequency, urinary tract infection.
Hydrochlorothiazide
- Other adverse experiences that have been reported with hydrochlorothiazide, without regard to causality, are listed below:
- Body as a Whole: weakness; Digestive: pancreatitis, jaundice (intrahepatic cholestatic jaundice), sialadenitis, cramping, gastric irritation; Hematologic: aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia; Hypersensitivity: purpura, photosensitivity, urticaria, necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory distress including pneumonitis and pulmonary edema; Metabolic: hyperglycemia, glycosuria, hyperuricemia; Musculoskeletal: muscle spasm; Nervous System/Psychiatric: restlessness; Renal: renal failure, renal dysfunction, interstitial nephritis; Skin: erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis; Special Senses: transient blurred vision, xanthopsia.
- Persistent dry cough (with an incidence of a few percent) has been associated with ACE-inhibitor use and in practice can be a cause of discontinuation of ACE-inhibitor therapy. Two prospective, parallel-group, double-blind, randomized, controlled trials were conducted to assess the effects of losartan on the incidence of cough in hypertensive patients who had experienced cough while receiving ACE-inhibitor therapy. Patients who had typical ACE-inhibitor cough when challenged with lisinopril, whose cough disappeared on placebo, were randomized to losartan 50 mg, lisinopril 20 mg, or either placebo (one study, n=97) or 25 mg hydrochlorothiazide (n=135). The double-blind treatment period lasted up to 8 weeks. The incidence of cough is shown below.
- These studies demonstrate that the incidence of cough associated with losartan therapy, in a population that all had cough associated with ACE-inhibitor therapy, is similar to that associated with hydrochlorothiazide or placebo therapy.
- Cases of cough, including positive re-challenges, have been reported with the use of losartan in postmarketing experience.
Severe Hypertension
- In a clinical study in patients with severe hypertension (SiDBP 110 mmHg), the overall pattern of adverse events reported through six weeks of follow-up was similar in patients treated with Losartan Potassium and Hydrochlorothiazide Tablets as initial therapy and in patients treated with losartan as initial therapy. There were no reported cases of syncope in either treatment group. There were 2 (0.6%) and 0 (0.0%) cases of hypotension reported in the group treated with Losartan Potassium and Hydrochlorothiazide Tablets and the group treated with losartan, respectively. There were 3 (0.8%) and 2 (1.2%) cases of increased serum creatinine (>0.5 mg/dL) in the group treated with Losartan Potassium and Hydrochlorothiazide Tablets and the group treated with losartan, respectively, during the same time period (See PHARMACOLOGY, Pharmacodynamics and Clinical Effects, Severe hypertension.)

## Postmarketing Experience
- The following additional adverse reactions have been reported in postmarketing experience:
- Digestive: Hepatitis has been reported rarely in patients treated with losartan.
- Hemic: Thrombocytopenia.
- Hypersensitivity: Angioedema, including swelling of the larynx and glottis, causing airway obstruction and/or swelling of the face, lips, pharynx, and/or tongue has been reported rarely in patients treated with losartan; some of these patients previously experienced angioedema with other drugs including ACE inhibitors. Vasculitis, including Henoch-Schonlein purpura, has been reported with losartan. Anaphylactic reactions have been reported.
- Metabolic and Nutrition: Hyperkalemia, hyponatremia have been reported with losartan.
- Musculoskeletal: Rare cases of rhabdomyolysis have been reported in patients receiving angiotensin II receptor blockers.
- Respiratory: Dry cough (see above) has been reported with losartan.
- Skin: Erythroderma has been reported with losartan.
Laboratory Test Findings
- In controlled clinical trials, clinically important changes in standard laboratory parameters were rarely associated with administration of Losartan Potassium and Hydrochlorothiazide Tablets.
- Creatinine, Blood Urea Nitrogen: Minor increases in blood urea nitrogen (BUN) or serum creatinine were observed in 0.6 and 0.8 percent, respectively, of patients with essential hypertension treated with Losartan Potassium and Hydrochlorothiazide Tablets alone. No patient discontinued taking Losartan Potassium and Hydrochlorothiazide Tablets due to increased BUN. One patient discontinued taking Losartan Potassium and Hydrochlorothiazide Tablets due to a minor increase in serum creatinine.
- Hemoglobin and Hematocrit: Small decreases in hemoglobin and hematocrit (mean decreases of approximately 0.14 grams percent and 0.72 volume percent, respectively) occurred frequently in patients treated with Losartan Potassium and Hydrochlorothiazide Tablets alone, but were rarely of clinical importance. No patients were discontinued due to anemia.
- Liver Function Tests: Occasional elevations of liver enzymes and/or serum bilirubin have occurred. In patients with essential hypertension treated with Losartan Potassium and Hydrochlorothiazide Tablets alone, no patients were discontinued due to these laboratory adverse experiences.
- Serum Electrolytes: See PRECAUTIONS.

# Drug Interactions
Losartan Potassium
- No significant drug-drug pharmacokinetic interactions have been found in interaction studies with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbital. Rifampin, an inducer of drug metabolism, decreased the concentrations of losartan and its active metabolite. In humans, two inhibitors of P450 3A4 have been studied. Ketoconazole did not affect the conversion of losartan to the active metabolite after intravenous administration of losartan, and erythromycin had no clinically significant effect after oral administration. Fluconazole, an inhibitor of P450 2C9, decreased active metabolite concentration and increased losartan concentration. The pharmacodynamic consequences of concomitant use of losartan and inhibitors of P450 2C9 have not been examined. Subjects who do not metabolize losartan to active metabolite have been shown to have a specific, rare defect in cytochrome P450 2C9. These data suggest that the conversion of losartan to its active metabolite is mediated primarily by P450 2C9 and not P450 3A4.
- As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to increases in serum potassium.
- Lithium: As with other drugs which affect the excretion of sodium, lithium excretion may be reduced. Therefore, serum lithium levels should be monitored carefully if lithium salts are to be co-administered with angiotensin II receptor antagonists.
- Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors): In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan) may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving losartan and NSAID therapy.
- The antihypertensive effect of angiotensin II receptor antagonists, including losartan, may be attenuated by NSAIDs, including selective COX-2 inhibitors.
- Dual Blockade of the Renin-Angiotensin System (RAS): Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Closely monitor blood pressure, renal function, and electrolytes in patients on Losartan Potassium and Hydrochlorothiazide Tablets and other agents that affect the RAS.
- Do not co-administer aliskiren with Losartan Potassium and Hydrochlorothiazide Tablets in patients with diabetes. Avoid use of aliskiren with Losartan Potassium and Hydrochlorothiazide Tablets in patients with renal impairment (GFR <60 ml/min).
Hydrochlorothiazide
- When administered concurrently, the following drugs may interact with thiazide diuretics:
- Alcohol, barbiturates, or narcotics  potentiation of orthostatic hypotension may occur.
- Antidiabetic drugs (oral agents and insulin)  dosage adjustment of the antidiabetic drug may be required.
- Other antihypertensive drugs  additive effect or potentiation.
- Cholestyramine and colestipol resins  Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85 and 43 percent, respectively.
- Corticosteroids, ACTH, or glycyrrhizin (found in liquorice)  intensified electrolyte depletion, particularly hypokalemia.
- Pressor amines (e.g., norepinephrine)  possible decreased response to pressor amines but not sufficient to preclude their use.
- Skeletal muscle relaxants, nondepolarizing (e.g., tubocurarine)  possible increased responsiveness to the muscle relaxant.
- Lithium  should not generally be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Refer to the package insert for lithium preparations before use of such preparations with Losartan Potassium and Hydrochlorothiazide Tablets.
- Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors)  The administration of a non-steroidal anti-inflammatory agent, including a selective cyclooxygenase-2 inhibitor, can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Therefore, when Losartan Potassium and Hydrochlorothiazide Tablets and non-steroidal anti-inflammatory agents, including selective cyclooxygenase-2 inhibitors, are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained.
- In patients receiving diuretic therapy, co-administration of NSAIDs with angiotensin receptor blockers, including losartan, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving hydrochlorothiazide, losartan, and NSAID therapy.

# Use in Specific Populations

### Pregnancy
Pregnancy Category (FDA): D
- Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue Losartan Potassium and Hydrochlorothiazide Tablets as soon as possible. These adverse outcomes are usually associated with the use of these drugs in the second and third trimester of pregnancy. Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus.
- In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus. Perform serial ultrasound examinations to assess the intra-amniotic environment.
- If oligohydramnios is observed, discontinue Losartan Potassium and Hydrochlorothiazide Tablets, unless it is considered life-saving for the mother. Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury.
- Closely observe infants with histories of in utero exposure to Losartan Potassium and Hydrochlorothiazide Tablets for hypotension, oliguria, and hyperkalemia.
- There was no evidence of teratogenicity in rats or rabbits treated with a maximum losartan potassium dose of 10 mg/kg/day in combination with 2.5 mg/kg/day of hydrochlorothiazide. At these dosages, respective exposures (AUCs) of losartan, its active metabolite, and hydrochlorothiazide in rabbits were approximately 5, 1.5, and 1.0 times those achieved in humans with 100 mg losartan in combination with 25 mg hydrochlorothiazide. AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide. Fetal toxicity in rats, as evidenced by a slight increase in supernumerary ribs, was observed when females were treated prior to and throughout gestation with 10 mg/kg/day losartan in combination with 2.5 mg/kg/day hydrochlorothiazide. As also observed in studies with losartan alone, adverse fetal and neonatal effects, including decreased body weight, renal toxicity, and mortality, occurred when pregnant rats were treated during late gestation and/or lactation with 50 mg/kg/day losartan in combination with 12.5 mg/kg/day hydrochlorothiazide. Respective AUCs for losartan, its active metabolite and hydrochlorothiazide at these dosages in rats were approximately 35, 10 and 10 times greater than those achieved in humans with the administration of 100 mg of losartan in combination with 25 mg hydrochlorothiazide. When hydrochlorothiazide was administered without losartan to pregnant mice and rats during their respective periods of major organogenesis, at doses up to 3000 and 1000 mg/kg/day, respectively, there was no evidence of harm to the fetus.
- Thiazides cross the placental barrier and appear in cord blood. There is a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.
- Hypotension - Volume-Depleted Patients
- In patients who are intravascularly volume-depleted (e.g., those treated with diuretics), symptomatic hypotension may occur after initiation of therapy with Losartan Potassium and Hydrochlorothiazide Tablets. This condition should be corrected prior to administration of Losartan Potassium and Hydrochlorothiazide Tablets.
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
- There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Losartan potassium and Hydrochlorothiazide in women who are pregnant.

### Labor and Delivery
- There is no FDA guidance on use of Losartan potassium and Hydrochlorothiazide during labor and delivery.

### Nursing Mothers
- It is not known whether losartan is excreted in human milk, but significant levels of losartan and its active metabolite were shown to be present in rat milk. Thiazides appear in human milk. Because of the potential for adverse effects on the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

### Pediatric Use
- Safety and effectiveness of Losartan Potassium and Hydrochlorothiazide Tablets in pediatric patients have not been established.
- Neonates with a history of in utero exposure to Losartan Potassium and Hydrochlorothiazide Tablets:
- If oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion. Exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function.

### Geriatic Use
- In a controlled clinical study for the reduction in the combined risk of cardiovascular death, stroke and myocardial infarction in hypertensive patients with left ventricular hypertrophy, 2857 patients (62%) were 65 years and over, while 808 patients (18%) were 75 years and over. In an effort to control blood pressure in this study, patients were coadministered losartan and hydrochlorothiazide 74% of the total time they were on study drug. No overall differences in effectiveness were observed between these patients and younger patients. Adverse events were somewhat more frequent in the elderly compared to non-elderly patients for both the losartan and hydrochlorothiazide and the control groups (see CLINICAL PHARMACOLOGY, Special Populations) .

### Gender
- There is no FDA guidance on the use of Losartan potassium and Hydrochlorothiazide with respect to specific gender populations.

### Race
- In the LIFE study, Black patients with hypertension and left ventricular hypertrophy had a lower risk of stroke on atenolol than on losartan (both cotreated with hydrochlorothiazide in the majority of patients). Given the difficulty in interpreting subset differences in large trials, it cannot be known whether the observed difference is the result of chance. However, the LIFE study does not provide evidence that the benefits of losartan on reducing the risk of cardiovascular events in hypertensive patients with left ventricular hypertrophy apply to Black patients (See CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects; Losartan Potassium, Reduction in the Risk of Stroke).

### Renal Impairment
- As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function have been reported in susceptible individuals treated with losartan; in some patients, these changes in renal function were reversible upon discontinuation of therapy.
- In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (e.g., patients with severe congestive heart failure), treatment with angiotensin converting enzyme inhibitors has been associated with oliguria and/or progressive azotemia and (rarely) with acute renal failure and/or death. Similar outcomes have been reported with losartan.
- In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN have been reported. Similar effects have been reported with losartan; in some patients, these effects were reversible upon discontinuation of therapy.
- Thiazides should be used with caution in severe renal disease. In patients with renal disease, thiazides may precipitate azotemia. Cumulative effects of the drug may develop in patients with impaired renal function.

### Hepatic Impairment
- There is no FDA guidance on the use of Losartan potassium and Hydrochlorothiazide in patients with hepatic impairment.

### Females of Reproductive Potential and Males
- There is no FDA guidance on the use of Losartan potassium and Hydrochlorothiazide in women of reproductive potentials and males.

### Immunocompromised Patients
- There is no FDA guidance one the use of Losartan potassium and Hydrochlorothiazide in patients who are immunocompromised.

# Administration and Monitoring

### Administration
Hypertension
- Dosing must be individualized. The usual starting dose of losartan is 50 mg once daily, with 25 mg recommended for patients with intravascular volume depletion (e.g., patients treated with diuretics) (see WARNINGS, Hypotension  Volume-Depleted Patients) and patients with a history of hepatic impairment. Losartan can be administered once or twice daily at total daily doses of 25 to 100 mg. If the antihypertensive effect measured at trough using once-a-day dosing is inadequate, a twice-a-day regimen at the same total daily dose or an increase in dose may give a more satisfactory response.
- Hydrochlorothiazide is effective in doses of 12.5 to 50 mg once daily and can be given at doses of 12.5 to 25 mg as Losartan Potassium and Hydrochlorothiazide Tablets.
- To minimize dose-independent side effects, it is usually appropriate to begin combination therapy only after a patient has failed to achieve the desired effect with monotherapy.
- The side effects (see WARNINGS) of losartan are generally rare and apparently independent of dose; those of hydrochlorothiazide are a mixture of dose-dependent (primarily hypokalemia) and dose-independent phenomena (e.g., pancreatitis), the former much more common than the latter. Therapy with any combination of losartan and hydrochlorothiazide will be associated with both sets of dose-independent side effects.
- Replacement Therapy: The combination may be substituted for the titrated components.
- Dose Titration by Clinical Effect: A patient whose blood pressure is not adequately controlled with losartan monotherapy (see above) or hydrochlorothiazide alone, may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily. If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily. A patient whose blood pressure is not adequately controlled with losartan 100 mg monotherapy (see above) may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/12.5 mg once daily. If blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
- A patient whose blood pressure is inadequately controlled by 25 mg once daily of hydrochlorothiazide, or is controlled but who experiences hypokalemia with this regimen, may be switched to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg (losartan 50 mg/hydrochlorothiazide 12.5 mg) once daily, reducing the dose of hydrochlorothiazide without reducing the overall expected antihypertensive response. The clinical response to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg should be subsequently evaluated, and if blood pressure remains uncontrolled after about 3 weeks of therapy, the dose may be increased to two tablets of Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg once daily or one tablet of Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/25 mg (losartan 100 mg/hydrochlorothiazide 25 mg) once daily.
- The usual dose of Losartan Potassium and Hydrochlorothiazide is one tablet of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily. More than two tablets of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily or more than one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily is not recommended. The maximal antihypertensive effect is attained about 3 weeks after initiation of therapy.
- Use in Patients with Renal Impairment: The usual regimens of therapy with Losartan Potassium and Hydrochlorothiazide Tablets may be followed as long as the patient's creatinine clearance is >30 mL/min. In patients with more severe renal impairment, loop diuretics are preferred to thiazides, so Losartan Potassium and Hydrochlorothiazide Tablets are not recommended.
- Patients with Hepatic Impairment: Losartan Potassium and Hydrochlorothiazide Tablets are not recommended for titration in patients with hepatic impairment (see WARNINGS, Impaired Hepatic function) because the appropriate 25 mg starting dose of losartan cannot be given.
Severe Hypertension
- The starting dose of Losartan Potassium and Hydrochlorothiazide Tablets for initial treatment of severe hypertension is one tablet of Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg once daily. For patients who do not respond adequately to Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg after 2 to 4 weeks of therapy, the dosage may be increased to one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily. The maximum dose is one tablet of Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg once daily. Losartan Potassium and Hydrochlorothiazide Tablets are not recommended as initial therapy in patients with hepatic impairment (see WARNINGS, Impaired Hepatic Function) because the appropriate 25 mg starting dose of losartan cannot be given. It is also not recommended for use as initial therapy in patients with intravascular volume depletion.
Hypertensive Patients with Left Ventricular Hypertrophy
- Treatment should be initiated with losartan potassium tablets 50 mg once daily. Hydrochlorothiazide 12.5 mg should be added or Losartan Potassium and Hydrochlorothiazide Tablets 50 mg/12.5 mg substituted if the blood pressure reduction is inadequate. If additional blood pressure reduction is needed, losartan potassium tablets 100 mg and hydrochlorothiazide 12.5 mg or Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/12.5 mg may be substituted, followed by losartan potassium tablets 100 mg and hydrochlorothiazide 25 mg or Losartan Potassium and Hydrochlorothiazide Tablets 100 mg/25 mg. For further blood pressure reduction other antihypertensives should be added.
- Losartan Potassium and Hydrochlorothiazide Tablets may be administered with other antihypertensive agents.
- Losartan Potassium and Hydrochlorothiazide Tablets may be administered with or without food.

### Monitoring
- As with other drugs which affect the excretion of sodium, lithium excretion may be reduced. Therefore, serum lithium levels should be monitored carefully if lithium salts are to be co-administered with angiotensin II receptor antagonists.
- Monitor renal function periodically in patients receiving losartan and NSAID therapy.
- Monitor blood pressure, renal function, and electrolytes in patients on Losartan Potassium and Hydrochlorothiazide Tablets and other agents that affect the RAS(NSAIDs).

# IV Compatibility
There is limited information regarding IV Compatibility of Losartan potassium and Hydrochlorothiazide in the drug label.

# Overdosage
There is limited information regarding Losartan potassium and Hydrochlorothiazide overdosage.  If you suspect drug poisoning or overdose, please contact the National Poison Help hotline (1-800-222-1222) immediately.

# Pharmacology

## Mechanism of Action
There is limited information regarding Losartan potassium and Hydrochlorothiazide Mechanism of Action in the drug label.

## Structure
- Losartan Potassium and Hydrochlorothiazide 50 mg/12.5 mg, Losartan Potassium and Hydrochlorothiazide 100 mg/12.5 mg and Losartan Potassium and Hydrochlorothiazide 100 mg/25 mg combine an angiotensin II receptor (type AT1) antagonist and a diuretic, hydrochlorothiazide.
- Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-imidazole-5-methanol monopotassium salt. Its empirical formula is C22H22ClKN6O, and its structural formula is:
Structural Formula
- Losartan potassium, USP is a white to off-white free-flowing crystalline powder with a molecular weight of 461.01. It is freely soluble in water, soluble in alcohols, and slightly soluble in common organic solvents, such as acetonitrile and methyl ethyl ketone.
- Oxidation of the 5-hydroxymethyl group on the imidazole ring results in the active metabolite of losartan.
- Hydrochlorothiazide is 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C7H8ClN3O4S2 and its structural formula is:
Structural Formula
- Hydrochlorothiazide, USP is a white, or practically white, crystalline powder with a molecular weight of 297.74, which is slightly soluble in water, but freely soluble in sodium hydroxide solution.
- Losartan Potassium and Hydrochlorothiazide Tablets, USP are available for oral administration in three tablet combinations of losartan and hydrochlorothiazide. Losartan Potassium and Hydrochlorothiazide Tablets, USP 50 mg/12.5 mg contain 50 mg of losartan potassium USP and 12.5 mg of hydrochlorothiazide USP. Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/12.5 mg contain 100 mg of losartan potassium USP and 12.5 mg of hydrochlorothiazide USP. Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/25 mg contain 100 mg of losartan potassium USP and 25 mg of hydrochlorothiazide USP. Inactive ingredients are colloidal silicon dioxide, hydroxypropyl cellulose, hypromellose, lactose anhydrous, magnesium stearate, microcrystalline cellulose, pregelatinized starch, talc and titanium dioxide. Losartan Potassium and Hydrochlorothiazide Tablets, USP 50 mg/12.5 mg and Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/25 mg also contain D&C yellow No. 10 lake.
- Losartan Potassium and Hydrochlorothiazide Tablets, USP 50 mg/12.5 mg contain 4.24 mg (0.108 mEq) of potassium, Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/12.5 mg contain 8.48 mg (0.216 mEq) of potassium, and Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/25 mg contain 8.48 mg (0.216 mEq) of potassium.

## Pharmacodynamics
- There is limited information regarding Pharmacodynamics of Losartan potassium and Hydrochlorothiazide in the drug label.

## Pharmacokinetics
- There is limited information regarding Pharmacokinetics of Losartan potassium and Hydrochlorothiazide in the drug label.

## Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
Losartan Potassium and Hydrochlorothiazide
- No carcinogenicity studies have been conducted with the losartan potassium and hydrochlorothiazide combination.
- Losartan potassium and hydrochlorothiazide when tested at a weight ratio of 4:1 was negative in the Ames microbial mutagenesis assay and the V-79 Chinese hamster lung cell mutagenesis assay. In addition, there was no evidence of direct genotoxicity in the in vitro alkaline elution assay in rat hepatocytes and in vitro chromosomal aberration assay in Chinese hamster ovary cells at noncytotoxic concentrations.
- Losartan potassium, coadministered with hydrochlorothiazide, had no effect on the fertility or mating behavior of male rats at dosages up to 135 mg/kg/day of losartan and 33.75 mg/kg/day of hydrochlorothiazide. These dosages have been shown to provide respective systemic exposures (AUCs) for losartan, its active metabolite and hydrochlorothiazide that are approximately 60, 60 and 30 times greater than those achieved in humans with 100 mg of losartan potassium in combination with 25 mg of hydrochlorothiazide. In female rats, however, the coadministration of doses as low as 10 mg/kg/day of losartan and 2.5 mg/kg/day of hydrochlorothiazide was associated with slight but statistically significant decreases in fecundity and fertility indices. AUC values for losartan, its active metabolite and hydrochlorothiazide, extrapolated from data obtained with losartan administered to rats at a dose of 50 mg/kg/day in combination with 12.5 mg/kg/day of hydrochlorothiazide, were approximately 6, 2, and 2 times greater than those achieved in humans with 100 mg of losartan in combination with 25 mg of hydrochlorothiazide.
Losartan Potassium
- Losartan potassium was not carcinogenic when administered at maximally tolerated dosages to rats and mice for 105 and 92 weeks, respectively. Female rats given the highest dose (270 mg/kg/day) had a slightly higher incidence of pancreatic acinar adenoma. The maximally tolerated dosages (270 mg/kg/day in rats, 200 mg/kg/day in mice) provided systemic exposures for losartan and its pharmacologically active metabolite that were approximately 160 and 90 times (rats) and 30 and 15 times (mice) the exposure of a 50 kg human given 100 mg per day.
- Losartan potassium was negative in the microbial mutagenesis and V-79 mammalian cell mutagenesis assays and in the in vitro alkaline elution and in vitro and in vivo chromosomal aberration assays. In addition, the active metabolite showed no evidence of genotoxicity in the microbial mutagenesis, in vitro alkaline elution, and in vitro chromosomal aberration assays.
- Fertility and reproductive performance were not affected in studies with male rats given oral doses of losartan potassium up to approximately 150 mg/kg/day. The administration of toxic dosage levels in females (300/200 mg/kg/day) was associated with a significant (p<0.05) decrease in the number of corpora lutea/female, implants/female, and live fetuses/female at C-section. At 100 mg/kg/day only a decrease in the number of corpora lutea/female was observed. The relationship of these findings to drug-treatment is uncertain since there was no effect at these dosage levels on implants/pregnant female, percent post-implantation loss, or live animals/litter at parturition. In nonpregnant rats dosed at 135 mg/kg/day for 7 days, systemic exposure (AUCs) for losartan and its active metabolite were approximately 66 and 26 times the exposure achieved in man at the maximum recommended human daily dosage (100 mg).
Hydrochlorothiazide
- Two-year feeding studies in mice and rats conducted under the auspices of the National Toxicology Program (NTP) uncovered no evidence of a carcinogenic potential of hydrochlorothiazide in female mice (at doses of up to approximately 600 mg/kg/day) or in male and female rats (at doses of up to approximately 100 mg/kg/day). The NTP, however, found equivocal evidence for hepatocarcinogenicity in male mice.
- Hydrochlorothiazide was not genotoxic in vitro in the Ames mutagenicity assay of Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537, and TA 1538 and in the Chinese Hamster Ovary (CHO) test for chromosomal aberrations, or in vivo in assays using mouse germinal cell chromosomes, Chinese hamster bone marrow chromosomes, and the Drosophila sex-linked recessive lethal trait gene. Positive test results were obtained only in the in vitro CHO Sister Chromatid Exchange (clastogenicity) and in the Mouse Lymphoma Cell (mutagenicity) assays, using concentrations of hydrochlorothiazide from 43 to 1300 g/mL, and in the Aspergillus nidulans non-disjunction assay at an unspecified concentration.
- Hydrochlorothiazide had no adverse effects on the fertility of mice and rats of either sex in studies wherein these species were exposed, via their diet, to doses of up to 100 and 4 mg/kg, respectively, prior to mating and throughout gestation.

# Clinical Studies
There is limited information regarding Losartan potassium and Hydrochlorothiazide Clinical Studies in the drug label.

# How Supplied
- Losartan Potassium and Hydrochlorothiazide Tablets, USP 50 mg/12.5 mg are light yellow colored, oval shaped, biconvex film coated tablets, debossed with "116" on one side and plain on other side.
- Bottles of 30- NDC 13668-116-30
- Bottles of 90- NDC 13668-116-90
- Bottles of 1000- NDC 13668-116-10
- 100 Unit Dose Tablets- NDC 13668-116-74
- Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/12.5 mg are white to off white colored, oval shaped, biconvex film coated tablets, debossed with "1117" on one side and plain on other side.
- Bottles of 30- NDC 13668-117-30
- Bottles of 90- NDC 13668-117-90
- Bottles of 1000- NDC 13668-117-10
- 100 Unit Dose Tablets- NDC 13668-117-74
- Losartan Potassium and Hydrochlorothiazide Tablets, USP 100 mg/25 mg are yellow colored, oval shaped, biconvex film coated tablets, debossed with "1118" on one side and plain on other side.
- Bottles of 30- NDC 13668-118-30
- Bottles of 90- NDC 13668-118-90
- Bottles of 1000- NDC 13668-118-10
100 Unit Dose Tablets- NDC 13668-118-74

## Storage
- Store at 20 to 25C (68 to 77F) (See USP controlled room temperature). Protect from light. Keep container tightly closed.

# Images

## Drug Images

## Package and Label Display Panel

# Patient Counseling Information
Impaired Renal Function
- As a consequence of inhibiting the renin-angiotensin-aldosterone system, changes in renal function have been reported in susceptible individuals treated with losartan; in some patients, these changes in renal function were reversible upon discontinuation of therapy.
- In patients whose renal function may depend on the activity of the renin-angiotensin-aldosterone system (e.g., patients with severe congestive heart failure), treatment with angiotensin converting enzyme inhibitors has been associated with oliguria and/or progressive azotemia and (rarely) with acute renal failure and/or death. Similar outcomes have been reported with losartan.
- In studies of ACE inhibitors in patients with unilateral or bilateral renal artery stenosis, increases in serum creatinine or BUN have been reported. Similar effects have been reported with losartan; in some patients, these effects were reversible upon discontinuation of therapy.
- Thiazides should be used with caution in severe renal disease. In patients with renal disease, thiazides may precipitate azotemia. Cumulative effects of the drug may develop in patients with impaired renal function.
Information for Patients
- Pregnancy: Female patients of childbearing age should be told about the consequences of exposure to Losartan Potassium and Hydrochlorothiazide Tablets during pregnancy. Discuss treatment options with women planning to become pregnant. Patients should be asked to report pregnancies to their physicians as soon as possible.
- Symptomatic Hypotension: A patient receiving Losartan Potassium and Hydrochlorothiazide Tablets should be cautioned that lightheadedness can occur, especially during the first days of therapy, and that it should be reported to the prescribing physician. The patients should be told that if syncope occurs, Losartan Potassium and Hydrochlorothiazide Tablets should be discontinued until the physician has been consulted.
- All patients should be cautioned that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to an excessive fall in blood pressure, with the same consequences of lightheadedness and possible syncope.
- Potassium Supplements: A patient receiving Losartan Potassium and Hydrochlorothiazide Tablets should be told not to use potassium supplements or salt substitutes containing potassium without consulting the prescribing physician (see PRECAUTIONS,DrugInteractions, Losartan Potassium).

# Precautions with Alcohol
- Alcohol-Losartan potassium and Hydrochlorothiazide interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

# Brand Names
Hyzaar

# Look-Alike Drug Names
- A  B

# Drug Shortage Status

# Price