Meropenem precautions

# Precautions

## General
Prescribing Meropenem  in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
Seizures and other adverse CNS experiences have been reported during treatment with Meropenem  These experiences have occurred most commonly in patients with CNS disorders (e.g., brain lesions or history of seizures) or with bacterial meningitis and/or compromised renal function.
During clinical investigations, 2904 immunocompetent adult patients were treated for infections outside the CNS, with the overall seizure rate being 0.7% (based on 20 patients with this adverse event).  All meropenem-treated patients with seizures had pre-existing contributing factors.  Among these are included prior history of seizures or CNS abnormality and concomitant medications with seizure potential.  Dosage adjustment is recommended in patients with advanced age and/or reduced renal function. (See  DOSAGE AND ADMINISTRATION - Use in Adults with Renal Impairment.)
Close adherence to the recommended  dosage regimens is urged, especially in patients with known factors that predispose to convulsive activity. Anticonvulsant therapy should be continued in patients with known seizure disorders. If focal tremors,  Myoclonus, or seizure occur, patients should be evaluated neurologically, placed on Anticonvulsant therapy if not already instituted, and the dosage of Meropenem  re-examined to determine whether it should be decreased or the antibiotic discontinued.
In patients with renal dysfunction, thrombocytopenia has been observed but no clinical bleeding reported.  (See DOSAGE AND ADMINISTRATION - Use in Adults with Renal Impairment.)
There is inadequate information regarding the use of Meropenem  in patients on hemodialysis.
As with other broad-spectrum antibiotics, prolonged use of meropenem may result in overgrowth of nonsusceptible organisms.  Repeated evaluation of the patient is essential.  If superinfection does occur during therapy, appropriate measures should be taken.

## Laboratory Tests
While Meropenem  possesses the characteristic low toxicity of the beta-lactam group of antibiotics, periodic assessment of organ system functions, including renal, hepatic,  and hematopoietic, is advisable during prolonged therapy.

## Drug Interactions
Probenecid competes with meropenem for active tubular secretion and thus inhibits the renal excretion of meropenem. This led to statistically significant increases in the elimination half-life (38%) and in the extent of systemic exposure (56%). Therefore, the coadministration of probenecid with meropenem is not recommended.
There is evidence that meropenem may reduce serum levels of valproic acid to subtherapeutic levels (therapeutic range considered to be 50 to 100 g/mL total valproate).

## Carcinogenesis, Mutagenesis, Impairment of Fertility:

### Carcinogenesis
Carcinogenesis studies have not been performed.

### Mutagenesis
Genetic toxicity studies were performed with meropenem using the bacterial reverse mutation test, the Chinese hamster ovary HGPRT assay, cultured human lymphocytescytogenic assay, and the mouse micronucleus test. There was no evidence of mutagenic potential found in any of these tests.

### Impairment of fertility
Reproductive studies were performed with meropenem in rats at doses up to 1000 mg/kg/day, and cynomolgus monkeys at doses up to 360 mg/kg/day (on the basis of AUC comparisons,approximately 1.8 times and 3.7 times, respectively, to the human exposure at the usual dose of 1 g every 8 hours). There was no reproductive toxicity seen.
Reproductive studies have been performed with meropenem in rats at doses of up to 1000 mg/kg/day, and cynomolgus monkeys at doses of up to 360 mg/kg/day (on the basis of AUC comparisons, approximately 1.8 times and 3.7 times, respectively, to the human exposure at the usual dose of 1 g every 8 hours). These studies revealed no evidence of  impaired fertility or harm to the fetus due to meropenem, although there were slight changes in fetal body weight at doses of 250 mg/kg/day (on the basis of AUC comparisons, 0.4 times the human exposure at a dose of 1 g every 8 hours) and above in rats. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

## Pediatric Use
The safety and effectiveness of Meropenem  have been established for pediatric patients  3 months of age. Use of Meropenem  in pediatric patients with bacterial meningitis is supported by evidence from adequate and well-controlled studies in the pediatric population. Use of Meropenem  in pediatric patients with intra-abdominal infections is supported by evidence from adequate and well-controlled studies with adults with additional data from pediatric pharmacokinetics studies and controlled clinical trials in pediatric patients. Use of Meropenem  in pediatric patients with complicated skin and skin structure infections is supported by evidence from an adequate and well-controlled study with adults and additional data from pediatric pharmacokinetics studies. (See CLINICAL PHARMACOLOGY, INDICATIONS AND USAGE, ADVERSE REACTIONS, DOSAGE AND ADMINISTRATION, and CLINICAL STUDIES sections.)

## Nursing Mothers
It is not known whether this drug is excreted in  human milk.  Because many drugs are excreted in human milk, caution should be exercised when Meropenem  is administered to a nursing woman.

## Geriatric Use
Of the total number of subjects in clinical studies of Meropenem , approximately 1100 (30%) were 65 years of age and older, while 400 (11%) were 75 years and older.  Additionally, in a study of 511 patients with complicated skin and skin structure infections 93 (18%) were 65 years of age and older, while 38 (7%) were 75 years and older.  No overall differences in safety or effectiveness were observed between these subjects and younger subjects; spontaneous reports and other reported clinical experience have not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
A pharmacokinetic study with Meropenem  in elderly patients with renal insufficiency has shown a reduction in plasma clearance of meropenem that correlates with age-associated reduction in creatinine clearance. (See DOSAGE AND ADMINISTRATION; Use in Adults with Renal Impairment).
Meropenem  is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function.  Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

## Information For Patients
Patients should be counseled that antibacterial drugs including Meropenem  should only be used to treat bacterial infections.  They do not treat viral infections (eg, the common cold).  When Meropenem  is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed.  Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Meropenem  or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued.  Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever)  even as late as two or more months after having taken the last dose of the antibiotic.  If this occurs, patients should contact their physician as soon as possible.