Desvenlafaxine

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# Black Box Warning

# Overview
Desvenlafaxine is a serotonin and norepinephrine reuptake inhibitor (SNRI) that is FDA approved for the treatment of major depressive disorder (MDD). There is a Black Box Warning for this drug as shown here.  Common adverse reactions include nausea, dizziness, insomnia, hyperhidrosis, constipation, somnolence, decreased appetite, anxiety, and specific male sexual function disorders.

# Adult Indications and Dosage

## FDA-Labeled Indications and Dosage (Adult)
- Dosing Information
- The recommended dose for Desvenlafaxine is 50 mg once daily, with or without food.
- In clinical studies, doses of 50 mg to 400 mg per day were shown to be effective, although no additional benefit was demonstrated at doses greater than 50 mg per day and adverse reactions and discontinuations were more frequent at higher doses.

## Off-Label Use and Dosage (Adult)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Desvenlafaxine in adult patients.

### NonGuideline-Supported Use
- Dosing Information
- Oral dose of 100 mg daily.

# Pediatric Indications and Dosage

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

## Off-Label Use and Dosage (Pediatric)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Desvenlafaxine in pediatric patients.

### NonGuideline-Supported Use
There is limited information regarding Off-Label NonGuideline-Supported Use of Desvenlafaxine in pediatric patients.

# Contraindications
- Hypersensitivity to desvenlafaxine succinate, venlafaxine hydrochloride or to any excipients in the Desvenlafaxine formulation. Angioedema has been reported in patients treated with Desvenlafaxine.
- The use of MAOIs intended to treat psychiatric disorders with Desvenlafaxine or within 7 days of stopping treatment with Desvenlafaxine is contraindicated because of an increased risk of serotonin syndrome. The use of Desvenlafaxine within 14 days of stopping an MAOI intended to treat psychiatric disorders is also contraindicated.
- Starting Desvenlafaxine in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome.

# Warnings

### Precautions
- Suicidal Thoughts and Behaviors in Children, Adolescents and Young Adults
- Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. Suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. There has been a long-standing concern, however, that antidepressants may have a role in inducing worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment. Pooled analyses of short-term placebo-controlled studies of antidepressant drugs (SSRIs and others) showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults (ages 18 to 24) with major depressive disorder (MDD) and other psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants compared to placebo in adults aged 65 and older.
- The pooled analyses of placebo-controlled studies in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term studies of 9 antidepressant drugs in over 4,400 patients. The pooled analyses of placebo-controlled studies in adults with MDD or other psychiatric disorders included a total of 295 short-term studies (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across the different indications, with the highest incidence in MDD. The risk differences (drug vs. placebo), however, were relatively stable within age strata and across indications. These risk differences (drug-placebo difference in the number of cases of suicidality per 1,000 patients treated) are provided in Table 1.
- No suicides occurred in any of the pediatric studies. There were suicides in the adult studies, but the number was not sufficient to reach any conclusion about drug effect on suicide.
- It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months. However, there is substantial evidence from placebo-controlled maintenance studies in adults with depression that the use of antidepressants can delay the recurrence of depression.
- All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases.
- The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality.
- Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse, or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
- If the decision has been made to discontinue treatment, medication should be tapered, as rapidly as is feasible, but with recognition that abrupt discontinuation can be associated with certain symptoms for a description of the risks of discontinuation of Desvenlafaxine].
- Families and caregivers of patients being treated with antidepressants for major depressive disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior, and the other symptoms described above, as well as the emergence of suicidality, and to report such symptoms immediately to healthcare providers. Such monitoring should include daily observation by families and caregivers.
- Prescriptions for Desvenlafaxine should be written for the smallest quantity of tablets consistent with good patient management, in order to reduce the risk of overdose.
- Screening patients for bipolar disorder
- A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled studies) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described above represent such a conversion is unknown. However, prior to initiating treatment with an antidepressant, patients with depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that Desvenlafaxine is not approved for use in treating bipolar depression.
- Serotonin Syndrome
- The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including Desvenlafaxine, alone but particularly with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St. John's Wort), and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
- Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Patients should be monitored for the emergence of serotonin syndrome.
- The concomitant use of Desvenlafaxine with MAOIs intended to treat psychiatric disorders is contraindicated. Desvenlafaxine should also not be started in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue. All reports with methylene blue that provided information on the route of administration involved intravenous administration in the dose range of 1 mg/kg to 8 mg/kg. No reports involved the administration of methylene blue by other routes (such as oral tablets or local tissue injection) or at lower doses. There may be circumstances when it is necessary to initiate treatment with a MAOI such as linezolid or intravenous methylene blue in a patient taking Desvenlafaxine. Desvenlafaxine should be discontinued before initiating treatment with the MAOI.
- If concomitant use of Desvenlafaxine with other serotonergic drugs, including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, and St. John's Wort is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases.
- Treatment with Desvenlafaxine and any concomitant serotonergic agents should be discontinued immediately if the above events occur and supportive symptomatic treatment should be initiated.
- Elevated Blood Pressure
- Patients receiving Desvenlafaxine should have regular monitoring of blood pressure since increases in blood pressure were observed in clinical studies. Pre-existing hypertension should be controlled before initiating treatment with Desvenlafaxine. Caution should be exercised in treating patients with pre-existing hypertension, cardiovascular, or cerebrovascular conditions that might be compromised by increases in blood pressure. Cases of elevated blood pressure requiring immediate treatment have been reported with Desvenlafaxine.
- Sustained blood pressure increases could have adverse consequences. For patients who experience a sustained increase in blood pressure while receiving Desvenlafaxine, either dose reduction or discontinuation should be considered.
- Abnormal Bleeding
- SSRIs and SNRIs, including Desvenlafaxine, may increase the risk of bleeding events. Concomitant use of aspirin, nonsteroidal anti-inflammatory drugs, warfarin, and other anticoagulants may add to this risk. Case reports and epidemiological studies (case-control and cohort design) have demonstrated an association between use of drugs that interfere with serotonin reuptake and the occurrence of gastrointestinal bleeding. Bleeding events related to SSRIs and SNRIs have ranged from ecchymosis, hematoma, epistaxis, and petechiae to life-threatening hemorrhages. Patients should be cautioned about the risk of bleeding associated with the concomitant use of Desvenlafaxine and NSAIDs, aspirin, or other drugs that affect coagulation or bleeding.
- Angle Closure Glaucoma
- Angle-Closure Glaucoma: The pupillary dilation that occurs following use of many antidepressant drugs including Desvenlafaxine may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.
- Activation of Mania/Hypomania
- During all MDD phase 2 and phase 3 studies, mania was reported for approximately 0.02% of patients treated with Desvenlafaxine. Activation of mania/hypomania has also been reported in a small proportion of patients with major affective disorder who were treated with other marketed antidepressants. As with all antidepressants, Desvenlafaxine should be used cautiously in patients with a history or family history of mania or hypomania.
- Discontinuation Syndrome
- Discontinuation symptoms have been systematically and prospectively evaluated in patients treated with Desvenlafaxine during clinical studies in Major Depressive Disorder. Abrupt discontinuation or dose reduction has been associated with the appearance of new symptoms that include dizziness, nausea, headache, irritability, insomnia, diarrhea, anxiety, fatigue, abnormal dreams, and hyperhidrosis. In general, discontinuation events occurred more frequently with longer duration of therapy.
- During marketing of SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), and SSRIs (Selective Serotonin Reuptake Inhibitors), there have been spontaneous reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g., paresthesia, such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, and seizures. While these events are generally self-limiting, there have been reports of serious discontinuation symptoms.
- Patients should be monitored for these symptoms when discontinuing treatment with Desvenlafaxine. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose, but at a more gradual rate.
- Seizure
- Cases of seizure have been reported in pre-marketing clinical studies with Desvenlafaxine. Desvenlafaxine has not been systematically evaluated in patients with a seizure disorder. Patients with a history of seizures were excluded from pre-marketing clinical studies. Desvenlafaxine should be prescribed with caution in patients with a seizure disorder.
- Hyponatremia
- Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including Desvenlafaxine. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Cases with serum sodium lower than 110 mmol/L have been reported. Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs. Also, patients taking diuretics or who are otherwise volume depleted can be at greater risk. Discontinuation of Desvenlafaxine should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.
- Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which can lead to falls. Signs and symptoms associated with more severe and/or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death.
- Interstitial Lung Disease and Eosinophilic Pneumonia
- Interstitial lung disease and eosinophilic pneumonia associated with venlafaxine (the parent drug of Desvenlafaxine) therapy have been rarely reported. The possibility of these adverse events should be considered in patients treated with Desvenlafaxine who present with progressive dyspnea, cough, or chest discomfort. Such patients should undergo a prompt medical evaluation, and discontinuation of Desvenlafaxine should be considered.

# Adverse Reactions

## Clinical Trials Experience
- Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in clinical practice.
- Patient exposure
- Desvenlafaxine was evaluated for safety in 8,394 patients diagnosed with major depressive disorder who participated in multiple-dose pre-marketing studies, representing 2,784 patient-years of exposure. Of the total 8,394 patients exposed to at least one dose of Desvenlafaxine; 2,116 were exposed to Desvenlafaxine for 6 months, representing 1,658 patient-years of exposure, and 421 were exposed for one year, representing 416 patient-years of exposure.
- Adverse reactions reported as reasons for discontinuation of treatment
- In the pre-marketing pooled 8-week placebo-controlled studies in patients with MDD, 1,834 patients were exposed to Desvenlafaxine (50 to 400 mg). Of the 1,834 patients, 12% discontinued treatment due to an adverse reaction, compared with 3% of the 1,116 placebo-treated patients. At the recommended dose of 50 mg, the discontinuation rate due to an adverse reaction for Desvenlafaxine (4.1%) was similar to the rate for placebo (3.8%). For the 100 mg dose of Desvenlafaxine the discontinuation rate due to an adverse reaction was 8.7%.
- The most common adverse reactions leading to discontinuation in at least 2% and at a rate greater than placebo of the Desvenlafaxine treated patients in the short-term studies, up to 8 weeks, were: nausea (4%); dizziness, headache and vomiting (2% each). In a longer-term study, up to 9 months, the most common was vomiting (2%).
- Common adverse reactions in placebo-controlled MDD studies
- The most commonly observed adverse reactions in Desvenlafaxine treated MDD patients in pre-marketing pooled 8-week, placebo-controlled, fixed-dose studies (incidence  5% and at least twice the rate of placebo in the 50 or 100 mg dose groups) were: nausea, dizziness, insomnia, hyperhidrosis, constipation, somnolence, decreased appetite, anxiety, and specific male sexual function disorders.
- Table 2 shows the incidence of common adverse reactions that occurred in  2% of Desvenlafaxine treated MDD patients and twice the rate of placebo at any dose in the pre-marketing pooled 8-week, placebo-controlled, fixed dose clinical studies.
- Sexual function adverse reactions
- Table 3 shows the incidence of sexual function adverse reactions that occurred in  2% of Desvenlafaxine treated MDD patients in any fixed-dose group (pre-marketing pooled 8-week, placebo-controlled, fixed -dose, clinical studies).
- Other adverse reactions observed in premarketing and postmarketing clinical studies
- Other infrequent adverse reactions, not described elsewhere in the label, occurring at an incidence of < 2% in MDD patients treated with Desvenlafaxine were:
Tachycardia.
Asthenia.
Weight increased, liver function test abnormal, blood prolactin increased.
Musculoskeletal stiffness.
Syncope, convulsion, dystonia.
Depersonalization, bruxism.
Urinary retention.
Rash, alopecia, photosensitivity reaction, angioedema.
- In clinical studies, there were uncommon reports of ischemic cardiac adverse reactions, including myocardial ischemia, myocardial infarction, and coronary occlusion requiring revascularization; these patients had multiple underlying cardiac risk factors. More patients experienced these events during Desvenlafaxine treatment as compared to placebo.
- Laboratory, ECG and vital sign changes observed in MDD clinical studies
- The following changes were observed in pre-marketing placebo-controlled, short-term MDD studies with Desvenlafaxine.
- Lipids
- Elevations in fasting serum total cholesterol, LDL (low density lipoproteins) cholesterol, and triglycerides occurred in the controlled studies. Some of these abnormalities were considered potentially clinically significant.
- The percentage of patients who exceeded a predetermined threshold value is shown in Table 4.
- Proteinuria
- Proteinuria, greater than or equal to trace, was observed in the pre-marketing fixed-dose controlled studies (see Table 5). This proteinuria was not associated with increases in BUN or creatinine and was generally transient.
- Vital sign changes
- Table 6 summarizes the changes that were observed in placebo-controlled, short-term, pre-marketing studies with Desvenlafaxine in patients with MDD (doses 50 to 400 mg).
- Treatment with Desvenlafaxine at all doses from 50 mg/day to 400 mg/day in controlled studies was associated with sustained hypertension, defined as treatment-emergent supine diastolic blood pressure (SDBP) 90 mm Hg and 10 mm Hg above baseline for 3 consecutive on-therapy visits (see Table 7). Analyses of patients in Desvenlafaxine pre-marketing short-term controlled studies who met criteria for sustained hypertension revealed a consistent increase in the proportion of patients who developed sustained hypertension. This was seen at all doses with a suggestion of a higher rate at 400 mg/day.
- Orthostatic hypotension
- In the pre-marketing short-term, placebo-controlled clinical studies with doses of 50 to 400 mg, systolic orthostatic hypotension (decrease 30 mm Hg from supine to standing position) occurred more frequently in patients 65 years of age receiving Desvenlafaxine (8%, 7/87) versus placebo (2.5%, 1/40), compared to patients <65 years of age receiving Desvenlafaxine (0.9%, 18/1,937) versus placebo (0.7%, 8/1,218).

## Postmarketing Experience
- The following adverse reaction has been identified during post-approval use of Desvenlafaxine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:
Stevens-Johnson syndrome.

# Drug Interactions
- Monoamine Oxidase Inhibitors (MAOI)
- Do not use MAOIs intended to treat psychiatric disorders with desvenlafaxine or within 7 days of stopping treatment with desvenlafaxine. Do not use desvenlafaxine within 14 days of stopping an MAOI intended to treat psychiatric disorders. In addition, do not start desvenlafaxine in a patient who is being treated with linezolid or intravenous methylene blue.
- Serotonergic Drugs
- Based on the mechanism of action of desvenlafaxine and the potential for serotonin syndrome, caution is advised when desvenlafaxine is co-administered with other drugs that may affect the serotonergic neurotransmitter systems.
- Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, and Warfarin)
- Serotonin release by platelets plays an important role in hemostasis. Epidemiological studies of case-control and cohort design that have demonstrated an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of upper gastrointestinal bleeding. These studies have also shown that concurrent use of an NSAID or aspirin may potentiate this risk of bleeding. Altered anticoagulant effects, including increased bleeding, have been reported when SSRIs and SNRIs are co-administered with warfarin. Patients receiving warfarin therapy should be carefully monitored when Desvenlafaxine is initiated or discontinued.
- Potential for Other Drugs to Affect Desvenlafaxine
- Based on in vitro data, no dose adjustment is required for Desvenlafaxine when used concomitantly with inhibitors of CYP3A4 and CYP1A1, 1A2, 2A6, 2D6, 2C8, 2C9, 2C19, 2E1, and the P-glycoprotein transporter. Clinical studies have demonstrated no clinically significant pharmacokinetic interaction between Desvenlafaxine and strong CYP 3A4 inhibitors (Figure 1).
- Potential for Desvenlafaxine to Affect Other Drugs
- Clinical studies have shown that desvenlafaxine does not have a clinically relevant effect on CYP2D6 metabolism at the dose of 100 mg daily (Figure 2). Substrates primarily metabolized by CYP2D6 (e.g., desipramine , atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine) should be dosed at the original level when co-administered with Desvenlafaxine 100 mg or lower or when Desvenlafaxine is discontinued. Reduce the dose of these substrates by up to one-half if co-administered with 400 mg of Desvenlafaxine.
- No additional dose adjustment is required for concomitant use of substrates of CYP3A4, 1A2, 2A6, 2C8, 2C9, and 2C19 isozymes, and P-glycoprotein transporter. Clinical studies have demonstrated no clinically significant pharmacokinetic interaction between Desvenlafaxine and CYP3A4 substrates (Figure 2).
- Clinical studies have shown that desvenlafaxine (100 mg daily) does not have a clinically relevant effect on tamoxifen and aripiprazole, compounds that are metabolized by a combination of both CYP2D6 and CYP3A4 enzymes (Figure 2).
- In vitro studies showed minimal inhibitory effect of desvenlafaxine on the CYP2D6 isoenzyme.
- In vitro, desvenlafaxine does not inhibit or induce the CYP3A4 isozyme.
- In vitro, desvenlafaxine does not inhibit CYP1A2, 2A6, 2C8, 2C9, and 2C19, isozymes, and P-glycoprotein transporter and would not be expected to affect the pharmacokinetics of drugs that are substrates of these CYP isozymes and transporter.
- Other Drugs Containing Desvenlafaxine or Venlafaxine
- Avoid use of Desvenlafaxine with other desvenlafaxine-containing products or venlafaxine products. The concomitant use of Desvenlafaxine with other desvenlafaxine-containing products or venlafaxine will increase desvenlafaxine blood levels and increase dose-related adverse reactions.
- Ethanol
- A clinical study has shown that Desvenlafaxine does not increase the impairment of mental and motor skills caused by ethanol. However, as with all CNS-active drugs, patients should be advised to avoid alcohol consumption while taking Desvenlafaxine.
- Drug-Laboratory Test Interactions
- False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking desvenlafaxine. This is due to lack of specificity of the screening tests. False positive test results may be expected for several days following discontinuation of desvenlafaxine therapy. Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish desvenlafaxine from PCP and amphetamine.

# Use in Specific Populations

### Pregnancy
Pregnancy Category (FDA):
- Pregnancy Category C
- There are no adequate and well-controlled studies of Desvenlafaxine in pregnant women. In reproductive developmental studies in rats and rabbits with desvenlafaxine succinate, evidence of teratogenicity was not observed at doses up to 30 times a human dose of 100 mg/day (on a mg/m2 basis) in rats, and up to 15 times a human dose of 100 mg/day (on a mg/m2 basis) in rabbits. An increase in rat pup deaths was seen during the first 4 days of lactation when dosing occurred during gestation and lactation, at doses greater than 10 times a human dose of 100 mg/day (on a mg/m2 basis). Desvenlafaxine should be used during pregnancy only if the potential benefits justify the potential risks to the fetus.
- Clinical considerations
- A prospective longitudinal study of 201 women with history of major depression who were euthymic at the beginning of pregnancy, showed women who discontinued antidepressant medication during pregnancy were more likely to experience a relapse of major depression than women who continued antidepressant medication.
- Human data
- Neonates exposed to SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), or SSRIs (Selective Serotonin Reuptake Inhibitors), late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome.
- Animal data
- When desvenlafaxine succinate was administered orally to pregnant rats and rabbits during the period of organogenesis at doses up to 300 mg/kg/day and 75 mg/kg/day, respectively, no teratogenic effects were observed. These doses are 30 times a human dose of 100 mg/day (on a mg/m2 basis) in rats and 15 times a human dose of 100 mg/day (on a mg/m2 basis) in rabbits. However, fetal weights were decreased and skeletal ossification was delayed in rats in association with maternal toxicity at the highest dose, with a no-effect dose 10 times a human dose of 100 mg/day (on a mg/m2 basis).
- When desvenlafaxine succinate was administered orally to pregnant rats throughout gestation and lactation, there was a decrease in pup weights and an increase in pup deaths during the first four days of lactation at the highest dose of 300 mg/kg/day. The cause of these deaths is not known. The no-effect dose for rat pup mortality was 10 times a human dose of 100 mg/day (on a mg/m2 basis). Post-weaning growth and reproductive performance of the progeny were not affected by maternal treatment with desvenlafaxine succinate at a dose 30 times a human dose of 100 mg/day (on a mg/m2 basis).
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Desvenlafaxine in women who are pregnant.

### Labor and Delivery
There is no FDA guidance on use of Desvenlafaxine during labor and delivery.

### Nursing Mothers
- Desvenlafaxine (O-desmethylvenlafaxine) is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Desvenlafaxine, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

### Pediatric Use
- Safety and effectiveness in pediatric patients have not been established. Anyone considering the use of Desvenlafaxine in a child or adolescent must balance the potential risks with the clinical need.

### Geriatic Use
- Of the 4,158 patients in pre-marketing clinical studies with Desvenlafaxine, 6% were 65 years of age or older. No overall differences in safety or efficacy were observed between these patients and younger patients; however, in the short-term placebo-controlled studies, there was a higher incidence of systolic orthostatic hypotension in patients 65 years of age compared to patients <65 years of age treated with Desvenlafaxine. For elderly patients, possible reduced renal clearance of Desvenlafaxine should be considered when determining dose.
- SSRIs and SNRIs, including Desvenlafaxine, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse event.

### Gender
There is no FDA guidance on the use of Desvenlafaxine with respect to specific gender populations.

### Race
There is no FDA guidance on the use of Desvenlafaxine with respect to specific racial populations.

### Renal Impairment
- In subjects with renal impairment the clearance of Desvenlafaxine was decreased. In subjects with severe renal impairment (24-hr CrCl <30 mL/min, Cockcroft-Gault) and end-stage renal disease, elimination half-lives were significantly prolonged, increasing exposures to Desvenlafaxine; therefore, dosage adjustment is recommended in these patients.

### Hepatic Impairment
- The mean terminal half-life (t1/2) changed from approximately 10 hours in healthy subjects and subjects with mild hepatic impairment to 13 and 14 hours in moderate and severe hepatic impairment, respectively. The recommended dose in patients with moderate to severe hepatic impairment is 50 mg/day. Dose escalation above 100 mg/day is not recommended.

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

### Immunocompromised Patients
There is no FDA guidance one the use of Desvenlafaxine in patients who are immunocompromised.

# Administration and Monitoring

### Administration
- Oral

### Monitoring
- Patients receiving Desvenlafaxine should have regular monitoring of blood pressure.

# IV Compatibility
There is limited information regarding IV Compatibility of Desvenlafaxine in the drug label.

# Overdosage

## Acute Overdose

### Signs and Symptoms
- There is limited clinical trial experience with desvenlafaxine succinate overdosage in humans. However, desvenlafaxine (Desvenlafaxine) is the major active metabolite of venlafaxine. Overdose experience reported with venlafaxine (the parent drug of Desvenlafaxine) is presented below; the identical information can be found in the Overdosage section of the venlafaxine package insert.
- In postmarketing experience, overdose with venlafaxine (the parent drug of Desvenlafaxine) has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported events in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), sinus and ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported.
- Published retrospective studies report that venlafaxine overdosage may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants. Epidemiological studies have shown that venlafaxine-treated patients have a higher pre-existing burden of suicide risk factors than SSRI-treated patients. The extent to which the finding of an increased risk of fatal outcomes can be attributed to the toxicity of venlafaxine in overdosage, as opposed to some characteristic(s) of venlafaxine-treated patients, is not clear.

### Management
- No specific antidotes for Desvenlafaxine are known. In managing over dosage, consider the possibility of multiple drug involvement. In case of overdose, call Poison Control Center at 1-800-222-1222 for latest recommendations.

## Chronic Overdose
There is limited information regarding Chronic Overdose of Desvenlafaxine in the drug label.

# Pharmacology

## Mechanism of Action
- The exact mechanism of the antidepressant action of desvenlafaxine is unknown, but is thought to be related to the potentiation of serotonin and norepinephrine in the central nervous system, through inhibition of their reuptake. Non-clinical studies have shown that desvenlafaxine is a potent and selective serotonin and norepinephrine reuptake inhibitor (SNRI).

## Structure
- Desvenlafaxine is an extended-release tablet for oral administration that contains desvenlafaxine succinate, a structurally novel SNRI for the treatment of MDD. Desvenlafaxine (O-desmethylvenlafaxine) is the major active metabolite of the antidepressant venlafaxine, a medication used to treat major depressive disorder.
- Desvenlafaxine is designated RS-4-phenol and has the empirical formula of C16H25NO2 (free base) and C16H25NO2C4H6O4H2O (succinate monohydrate). Desvenlafaxine succinate monohydrate has a molecular weight of 399.48. The structural formula is shown below.
- Desvenlafaxine succinate is a white to off-white powder that is soluble in water. The solubility of desvenlafaxine succinate is pH dependent. Its octanol:aqueous system (at pH 7.0) partition coefficient is 0.21.
- Desvenlafaxine is formulated as an extended-release tablet for once-a-day oral administration.
- Each tablet contains 76 or 152 mg of desvenlafaxine succinate equivalent to 50 or 100 mg of desvenlafaxine, respectively.
- Inactive ingredients for the 50 mg tablet consist of hypromellose, microcrystalline cellulose, talc, magnesium stearate and film coating, which consists of polyvinyl alcohol, polyethylene glycol, talc, titanium dioxide, and iron oxides.
- Inactive ingredients for the 100 mg tablet consist of hypromellose, microcrystalline cellulose, talc, magnesium stearate and film coating, which consists of polyvinyl alcohol, polyethylene glycol, talc, titanium dioxide, iron oxide and FD&C yellow #6.

## Pharmacodynamics
- Desvenlafaxine lacked significant affinity for numerous receptors, including muscarinic-cholinergic, H1-histaminergic, or 1-adrenergic receptors in vitro. Desvenlafaxine also lacked monoamine oxidase (MAO) inhibitory activity.
- ECG changes
- Electrocardiograms were obtained from 1,492 desvenlafaxine treated patients with major depressive disorder and 984 placebo-treated patients in clinical studies lasting up to 8 weeks. No clinically relevant differences were observed between desvenlafaxine treated and placebo-treated patients for QT, QTc, PR, and QRS intervals. In a thorough QTc study with prospectively determined criteria, desvenlafaxine did not cause QT prolongation. No difference was observed between placebo and desvenlafaxine treatments for the QRS interval.

## Pharmacokinetics
- The single-dose pharmacokinetics of desvenlafaxine are linear and dose-proportional in a dose range of 50 to 600 mg/day. With once-daily dosing, steady-state plasma concentrations are achieved within approximately 4 to 5 days. At steady-state, multiple-dose accumulation of desvenlafaxine is linear and predictable from the single-dose pharmacokinetic profile.
- Absorption and distribution
- The absolute oral bioavailability of Desvenlafaxine after oral administration is about 80%.
- A food-effect study involving administration of Desvenlafaxine to healthy subjects under fasting and fed conditions (high-fat meal, 800 to 1000 calories) indicated that desvenlafaxine Cmax was increased about 16% in the fed state, while the AUCs were similar. This difference is not expected to be clinically significant; therefore, Desvenlafaxine can be taken without regard to meals.
- The plasma protein binding of desvenlafaxine is low (30%) and is independent of drug concentration. The desvenlafaxine volume of distribution at steady-state following intravenous administration is 3.4 L/kg, indicating distribution into nonvascular compartments.
- Metabolism and elimination
- Desvenlafaxine is primarily metabolized by conjugation (mediated by UGT isoforms) and, to a minor extent, through oxidative metabolism. CYP3A4 is the cytochrome P450 isozyme mediating the oxidative metabolism (N-demethylation) of desvenlafaxine. The CYP2D6 metabolic pathway is not involved, and after administration of 100 mg, the pharmacokinetics of desvenlafaxine was similar in subjects with CYP2D6 poor and extensive metabolizer phenotype. Approximately 45% of desvenlafaxine is excreted unchanged in urine at 72 hours after oral administration. Approximately 19% of the administered dose is excreted as the glucuronide metabolite and <5% as the oxidative metabolite (N,O-didesmethylvenlafaxine) in urine.
- Drug interaction studies
- Inhibitors of CYP3A4 (ketoconazole)
- CYP3A4 is a minor pathway for the metabolism of desvenlafaxine. In a clinical study, ketoconazole (200 mg BID) increased the area under the concentration vs. time curve (AUC) of desvenlafaxine (400 mg single dose) by about 43% and Cmax by about 8%. Concomitant use of desvenlafaxine with potent inhibitors of CYP3A4 may result in higher concentrations of desvenlafaxine.
- Inhibitors of other CYP enzymes
- Based on in vitro data, drugs that inhibit CYP isozymes 1A1, 1A2, 2A6, 2D6, 2C8, 2C9, 2C19, and 2E1 are not expected to have significant impact on the pharmacokinetic profile of desvenlafaxine.
- Drugs metabolized by CYP2D6 (e.g. desipramine, dextromethorphan, metoprolol, atomoxetine)
- In vitro studies showed minimal inhibitory effect of desvenlafaxine on CYP2D6. Clinical studies have shown that desvenlafaxine does not have a clinically relevant effect on CYP2D6 metabolism at the dose of 100 mg daily. When desvenlafaxine succinate was administered at a dose of 100 mg daily in conjunction with a single 50 mg dose of desipramine, a CYP2D6 substrate, the Cmax and AUC of desipramine increased approximately 25% and 17%, respectively. When 400 mg (8 times the recommended 50 mg dose) was administered, the Cmax and AUC of desipramine increased approximately 50% and 90%, respectively. Concomitant use of desvenlafaxine with a drug metabolized by CYP2D6 can result in higher concentrations of that drug.
- Drugs metabolized by CYP3A4 (midazolam)
- In vitro, desvenlafaxine does not inhibit or induce the CYP3A4 isozyme. In a clinical study, desvenlafaxine 400 mg daily (8 times the recommended 50 mg dose) was co-administered with a single 4 mg dose of midazolam (a CYP3A4 substrate). The AUC and Cmax of midazolam decreased by approximately 31% and 16%, respectively. Concomitant use of desvenlafaxine with a drug metabolized by CYP3A4 can result in lower exposures to that drug.
- Drugs metabolized by CYP1A2, 2A6, 2C8, 2C9 and 2C19
- In vitro, desvenlafaxine does not inhibit CYP1A2, 2A6, 2C8, 2C9, and 2C19 isozymes and would not be expected to affect the pharmacokinetics of drugs that are metabolized by these CYP isozymes.
- In vitro, desvenlafaxine is not a substrate or an inhibitor for the P-glycoprotein transporter. The pharmacokinetics of desvenlafaxine are unlikely to be affected by drugs that inhibit the P-glycoprotein transporter, and desvenlafaxine is not likely to affect the pharmacokinetics of drugs that are substrates of the P-glycoprotein transporter.
- Special populations
- Age
- In a study of healthy subjects administered doses of up to 300 mg, there was an approximate 32% increase in Cmax and a 55% increase in AUC in subjects older than 75 years of age (n = 17), compared with subjects 18 to 45 years of age (n = 16). Subjects 65 to 75 years of age (n = 15) had no change in Cmax, but an approximately 32% increase in AUC, compared to subjects 18 to 45 years of age.
- Gender
- In a study of healthy subjects administered doses of up to 300 mg, women had an approximately 25% higher Cmax and an approximately 10% higher AUC than age-matched men. No adjustment of dosage on the basis of gender is needed.
- Race
- Pharmacokinetic analysis showed that race (White, n = 466; Black, n = 97; Hispanic, n = 39; Other, n = 33) had no apparent effect on the pharmacokinetics of Desvenlafaxine. No adjustment of dosage on the basis of race is needed.
- Hepatic insufficiency
- The disposition of desvenlafaxine succinate after administration of 100 mg was studied in subjects with mild (Child-Pugh A, n = 8), moderate (Child-Pugh B, n = 8), and severe (Child-Pugh C, n = 8) hepatic impairment and to healthy subjects (n = 12).
- Average AUC was increased by approximately 31% and 35% in patients with moderate and severe hepatic impairment, respectively, as compared to healthy subjects. Average AUC values were similar in subjects with mild hepatic impairment and healthy subjects (< 5% difference).
- Systemic clearance (CL/F) was decreased by approximately 20% and 36% in patients with moderate and severe hepatic impairment, respectively, as compared to healthy subjects. CL/F values were comparable in mild hepatic impairment and healthy subjects (< 5% difference).
- The mean t1/2 changed from approximately 10 hours in healthy subjects and subjects with mild hepatic impairment to 13 and 14 hours in moderate and severe hepatic impairment, respectively. The recommended dose in patients with hepatic impairment is 50 mg/day. Dose escalation above 100 mg/day is not recommended.
- Renal insufficiency
- The disposition of desvenlafaxine after administration of 100 mg was studied in subjects with mild (n = 9), moderate (n = 8), severe (n = 7) and end-stage renal disease (ESRD) (n = 9) requiring dialysis and in healthy, age-matched control subjects (n = 8). Elimination was significantly correlated with creatinine clearance. Increases in AUCs of about 42% in mild renal impairment (24-hr CrCl = 50 to 80 mL/min, Cockcroft-Gault ), about 56% in moderate renal impairment (24-hr CrCl = 30 to 50 mL/min, C-G), about 108% in severe renal impairment (24-hr CrCl 30 mL/min, C-G), and about 116% in ESRD subjects were observed, compared with healthy, age-matched control subjects.
- The mean terminal half-life (t1/2) was prolonged from 11.1 hours in the control subjects to approximately 13.5, 15.5, 17.6, and 22.8 hours in mild, moderate, severe renal impairment and ESRD subjects, respectively. Less than 5% of the drug in the body was cleared during a standard 4-hour hemodialysis procedure.
- The maximum recommended dose in patients with moderate renal impairment is 50 mg per day. Dosage adjustment of 50 mg every other day is recommended in patients with severe renal impairment or ESRD.

## Nonclinical Toxicology
- Carcinogenesis
- Desvenlafaxine succinate administered by oral gavage to mice and rats for 2 years did not increase the incidence of tumors in either study.
- Mice received desvenlafaxine succinate at dosages up to 500/300 mg/kg/day (dosage lowered after 45 weeks of dosing). The 300 mg/kg/day dose is 15 times a human dose of 100 mg/day on a mg/m2 basis.
- Rats received desvenlafaxine succinate at dosages up to 300 mg/kg/day (males) or 500 mg/kg/day (females). The highest dose is 29 (males) or 48 (females) times a human dose of 100 mg/day on a mg/m2 basis.
- Mutagenesis
- Desvenlafaxine was not mutagenic in the in vitro bacterial mutation assay (Ames test) and was not clastogenic in an in vitro chromosome aberration assay in cultured CHO cells, an in vivo mouse micronucleus assay, or an in vivo chromosome aberration assay in rats. Additionally, desvenlafaxine was not genotoxic in the in vitro CHO mammalian cell forward mutation assay and was negative in the in vitro BALB/c-3T3 mouse embryo cell transformation assay.
- Impairment of fertility
- When desvenlafaxine succinate was administered orally to male and female rats, fertility was reduced at the high dose of 300 mg/kg/day, which is 30 times a human dose of 100 mg/day (on a mg/m2 basis). There was no effect on fertility at 100 mg/kg/day, approximately 10 times a human dose of 100 mg/day (on a mg/m2 basis).

# Clinical Studies
- The efficacy of Desvenlafaxine as a treatment for depression was established in four 8-week, randomized, double-blind, placebo-controlled, fixed-dose studies (at doses of 50 mg/day to 400 mg/day) in adult outpatients who met the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for major depressive disorder. In the first study, patients received 100 mg (n = 114), 200 mg (n = 116), or 400 mg (n = 113) of Desvenlafaxine once daily, or placebo (n = 118). In a second study, patients received either 200 mg (n = 121) or 400 mg (n = 124) of Desvenlafaxine once daily, or placebo (n = 124). In two additional studies, patients received 50 mg (n = 150 and n = 164) or 100 mg (n = 147 and n = 158) of Desvenlafaxine once daily, or placebo (n = 150 and n = 161).
- Desvenlafaxine showed superiority over placebo as measured by improvement in the 17-item Hamilton Rating Scale for Depression (HAM-D17) total score in four studies and overall improvement, as measured by the Clinical Global Impressions Scale - Improvement (CGI-I), in three of the four studies. In studies directly comparing 50 mg/day and 100 mg/day there was no suggestion of a greater effect with the higher dose and adverse reactions and discontinuations were more frequent at higher doses.
- Analyses of the relationships between treatment outcome and age and treatment outcome and gender did not suggest any differential responsiveness on the basis of these patient characteristics. There was insufficient information to determine the effect of race on outcome in these studies.
- In a longer-term trial (Study 5), adult outpatients meeting DSM-IV criteria for major depressive disorder, who responded to 8 weeks of open-label acute treatment with 50 mg/day desvenlafaxine and subsequently remained stable for 12 weeks on desvenlafaxine, were assigned randomly in a double-blind manner to remain on active treatment or switch to placebo for up to 26 weeks of observation for relapse. Response during the open-label phase was defined as a HAM-D17 total score of  11 and CGI-I  2 at the day 56 evaluation; stability was defined as HAM-D17 total score of  11 and CGI-I  2 at week 20 and not having a HAM-D17 total score of  16 or a CGI-I score  4 at any office visit. Relapse during the double-blind phase was defined as follows: (1) a HAM-D17 total score of  16 at any office visit, (2) discontinuation for unsatisfactory efficacy response, (3) hospitalized for depression, (4) suicide attempt, or (5) suicide. Patients receiving continued desvenlafaxine treatment experienced statistically significantly longer time to relapse compared with placebo. At 26 weeks, the Kaplan-Meier estimated proportion of relapse was 14% with desvenlafaxine treatment versus 30% with placebo.
- In another longer-term trial (Study 6), adult outpatients meeting DSM-IV criteria for major depressive disorder and who responded to 12 weeks of acute treatment with desvenlafaxine were assigned randomly to the same dose (200 or 400 mg/day) they had received during acute treatment or to placebo for up to 26 weeks of observation for relapse. Response during the open-label phase was defined as a HAM-D17 total score of  11 at the day 84 evaluation. Relapse during the double-blind phase was defined as follows: (1) a HAM-D17 total score of  16 at any office visit, (2) a CGI-I score of  6 (versus day 84) at any office visit, or (3) discontinuation from the trial due to unsatisfactory response. Patients receiving continued desvenlafaxine treatment experienced statistically significantly longer time to relapse over the subsequent 26 weeks compared with those receiving placebo. At 26 weeks, the Kaplan-Meier estimated proportion of relapse was 29% with desvenlafaxine treatment versus 49% with placebo.

# How Supplied
- Desvenlafaxine (desvenlafaxine) Extended-Release Tablets are available as follows:
- 50 mg, light pink, square pyramid tablet debossed with "W" (over) "50" on the flat side
- NDC 0008-1211-14, bottle of 14 tablets in unit-of-use package
- NDC 0008-1211-30, bottle of 30 tablets in unit-of-use package
- NDC 0008-1211-01, bottle of 90 tablets in unit-of-use package
- NDC 0008-1211-50, 10 blisters of 10 (HUD)
- 100 mg, reddish-orange, square pyramid tablet debossed with "W" (over) "100" on the flat side
- NDC 0008-1222-14, bottle of 14 tablets in unit-of-use package
- NDC 0008-1222-30, bottle of 30 tablets in unit-of-use package
- NDC 0008-1222-01, bottle of 90 tablets in unit-of-use package
- NDC 0008-1222-50, 10 blisters of 10 (HUD)
- Store at 20 to 25C (68 to 77F); excursions permitted to 15 to 30C (59 to 86F).
- Each tablet contains 76 or 152 mg of desvenlafaxine succinate equivalent to 50 or 100 mg of desvenlafaxine, respectively.
- The unit-of-use package is intended to be dispensed as a unit.
- The appearance of these tablets is a trademark of Wyeth Pharmaceuticals.

## Storage
There is limited information regarding Desvenlafaxine Storage in the drug label.

# Images

## Drug Images

## Package and Label Display Panel

# Patient Counseling Information
- Advise patients, their families, and their caregivers about the benefits and risks associated with treatment with Desvenlafaxine and counsel them in its appropriate use.
- Suicide Risk
- Advise patients, their families and caregivers to look for the emergence of suicidality, especially early during treatment and when the dose is adjusted up or down.
- Concomitant Medication
- Advise patients taking Desvenlafaxine not to use concomitantly other products containing desvenlafaxine or venlafaxine. Healthcare professionals should instruct patients not to take Desvenlafaxine with an MAOI or within 14 days of stopping an MAOI and to allow 7 days after stopping Desvenlafaxine before starting an MAOI.
- Serotonin Syndrome
- Caution patients about the risk of serotonin syndrome, particularly with the concomitant use of Desvenlafaxine with other serotonergic agents (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St. John's Wort supplements).
- Elevated Blood Pressure
- Advise patients that they should have regular monitoring of blood pressure when taking Desvenlafaxine.
- Abnormal Bleeding
- Patients should be cautioned about the concomitant use of Desvenlafaxine and NSAIDs, aspirin, warfarin, or other drugs that affect coagulation since combined use of psychotropic drugs that interfere with serotonin reuptake and these agents has been associated with an increased risk of bleeding.
- Narrow-angle Glaucoma
- Patients should be advised that taking Desvenlafaxine can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle closure glaucoma. Pre-existing glaucoma is almost always open-angle glaucoma because angle closure glaucoma, when diagnosed, can be treated definitively with iridectomy. Open-angle glaucoma is not a risk factor for angle closure glaucoma. Patients may wish to be examined to determine whether they are susceptible to angle closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible.
- Activation of Mania/Hypomania
- Advise patients, their families and caregivers to observe for signs of activation of mania/hypomania.
- Discontinuation
- Advise patients not to stop taking Desvenlafaxine without talking first with their healthcare professional. Patients should be aware that discontinuation effects may occur when stopping Desvenlafaxine.
- Switching Patients From Other Antidepressants to Desvenlafaxine
- Discontinuation symptoms have been reported when switching patients from other antidepressants, including venlafaxine, to Desvenlafaxine. Tapering of the initial antidepressant may be necessary to minimize discontinuation symptoms.
- Interference with Cognitive and Motor Performance
- Caution patients about operating hazardous machinery, including automobiles, until they are reasonably certain that Desvenlafaxine therapy does not adversely affect their ability to engage in such activities.
- Alcohol
- Advise patients to avoid alcohol while taking Desvenlafaxine.
- Allergic Reactions
- Advise patients to notify their physician if they develop allergic phenomena such as rash, hives, swelling, or difficulty breathing.
- Pregnancy
- Advise patients to notify their physician if they become pregnant or intend to become pregnant during therapy.
- Nursing
- Advise patients to notify their physician if they are breastfeeding an infant.
- Residual Inert Matrix Tablet
- Patients receiving Desvenlafaxine may notice an inert matrix tablet passing in the stool or via colostomy. Patients should be informed that the active medication has already been absorbed by the time the patient sees the inert matrix tablet.

# Precautions with Alcohol
- Avoid drinking alcohol while taking Desvenlafaxine.

# Brand Names
- PRISTIQ

# Look-Alike Drug Names
- PRISTIQ  Prilosec

# Drug Shortage Status

# Price