"Nov. 2, 2012 -- Safety steps taken in the wake of the fungal meningitis outbreak have worsened drug shortages, raising questions about whether the U.S. must choose between the safety and the availability of crucial medicines.
Carisoprodol has sedative properties and may impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a motor vehicle or operating machinery. There have been post-marketing reports of motor vehicle accidents associated with the use of carisoprodol.
Since the sedative effects of carisoprodol and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants) may be additive, appropriate caution should be exercised with patients who take more than one of these CNS depressants simultaneously.
Drug Dependence, Withdrawal, and Abuse
In the postmarketing experience with carisoprodol, cases of dependence, withdrawal, and abuse have been reported with prolonged use. Most cases of dependence, withdrawal, and abuse occurred in patients who have had a history of addiction or who used carisoprodol in combination with other drugs with abuse potential. However, there have been post-marketing adverse event reports of carisoprodol-associated abuse when used without other drugs with abuse potential. Withdrawal symptoms have been reported following abrupt cessation after prolonged use. To reduce the chance of carisoprodol dependence, withdrawal, or abuse, carisoprodol should be used with caution in addiction prone patients and in patients taking other CNS depressants including alcohol, and carisoprodol should be not be used more than two to three weeks for the relief of acute musculoskeletal discomfort.
One of the metabolites of cCarisoprodol, and one of its metabolites, meprobamate (a controlled substance), may cause dependence (see CLINICAL PHARMACOLOGY).
Serious Gastrointestinal Adverse Reactions
Aspirin can cause serious gastrointestinal (GI) adverse reactions including bleeding, perforation, and obstruction of the stomach, small intestine, or large intestine, which can be fatal. Aspirin-associated serious GI adverse reactions can occur anywhere along the GI tract, at any time, with or without warning symptoms. Patients at higher risk of aspirin-associated serious upper GI adverse reactions include patients with a history of aspirin-associated GI bleeding from ulcers (complicated ulcers), a history of aspirin-associated ulcers (uncomplicated ulcers), geriatric patients, patients with poor baseline health status, patients taking higher doses of aspirin, and patients taking concomitant anticoagulants, NSAIDs, and/or large amounts of alcohol. To minimize the risk for an aspirin-associated GI serious adverse reaction, the lowest effective aspirin dose should be used for the shortest possible duration.
Anaphylaxis and Anaphylactoid Reactions
Aspirin may cause an increased risk of serious anaphylaxis and anaphylactoid reactions, which can occur in patients without known prior exposure to aspirin (see CONTRAINDICATIONS). Patients with a serious anaphalaxis or anaphylactoid reaction should receive emergency care.
Patients with impaired renal or hepatic function
The safety and pharmacokinetics of Soma Compound (carisoprodol and aspirin) in patients with renal or hepatic impairment have not been evaluated.
Since carisoprodol is excreted by the kidney and is metabolized in the liver, caution should be exercised if carisoprodol is administered to patients with impaired renal or hepatic function. Carisoprodol is dialyzable by hemodialysis and peritoneal dialysis.
There have been postmarketing reports of seizures in patients who received carisoprodol. Most of these cases have occurred in the setting of multiple drug overdoses (including drugs of abuse, illegal drugs, and alcohol) (see OVERDOSAGE).
Gastrointestinal Adverse Reactions
In addition to serious gastrointestinal adverse reactions, the use of aspirin is also associated with gastritis, gastrointestinal erosions, abdominal pain, heartburn, vomiting, and nausea (see WARNINGS, Serious Gastrointestinal Adverse Reactions).
Carcinogenesis, Mutagenesis, Impairment of Fertility
No long-term studies of carcinogenesis have been done with Soma Compound (carisoprodol and aspirin) .
Carisoprodol: Long term studies in animals have not been performed to evaluate the carcinogenic potential of carisoprodol.
Carisoprodol was not formally evaluated for genotoxicity. In published studies, carisoprodol was mutagenic in the in vitro mouse lymphoma cell assay in the absence of metabolizing enzymes, but was not mutagenic in the presence of metabolizing enzymes. Carisoprodol was clastogenic in the in vitro chromosomal aberration assay using Chinese hamster ovary cells with or without the presence of metabolizing enzymes. Other types of genotoxic tests resulted in negative findings. Carisoprodol was not mutagenic in the Ames reverse mutation assay using S. typhimurium strains with or without metabolizing enzymes, and was not clastogenic in an in vivo mouse micronucleus assay of circulating blood cells.
Carisoprodol was not formally evaluated for effects on fertility. Published reproductive studies of carisoprodol in mice found no alteration in fertility although an alteration in reproductive cycles characterized by a greater time spent in estrus was observed at a carisoprodol dose of 1200 mg/kg/day. In a 13-week toxicology study that did not determine fertility, mouse testes weight and sperm motility were reduced at a dose of 1200 mg/kg/day. In both studies, the no effect level was 750 mg/kg/day, corresponding to approximately 2.6 times the human equivalent dosage of 350 mg four times a day, based on a body surface area comparison.
The significance of these findings for human fertility is not known.
Aspirin: Administration of aspirin for 68 weeks in the feed of rats was not carcinogenic. In the Ames Salmonella assay, aspirin was not mutagenic; however, aspirin did induce chromosome aberrations in cultured human fibroblasts. Aspirin has been shown to inhibit ovulation in rats (see Pregnancy.)
Pregnancy Category D.
It is not known whether Soma Compound (carisoprodol and aspirin) can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Adequate animal reproduction studies have not been conducted with Soma Compound. Soma Compound (carisoprodol and aspirin) should be given to a pregnant woman only if clearly needed.
Carisoprodol: There are no data on the use of carisoprodol during human pregnancy. Animal studies indicate that carisoprodol crosses the placenta and results in adverse effects on fetal growth and postnatal survival. The primary metabolite of carisoprodol, meprobamate, is an approved anxiolytic. Retrospective, post-marketing studies do not show a consistent association between maternal use of meprobamate and an increased risk for particular congenital malformations.
Animal studies have not adequately evaluated the teratogenic effects of carisoprodol. There was no increase in the incidence of congenital malformations noted in reproductive studies in rats, rabbits, and mice treated with meprobamate. Retrospective, post-marketing studies of meprobamate during human pregnancy were equivocal for demonstrating an increased risk of congenital malformations following first trimester exposure. Across studies that indicated an increased risk, the types of malformations were inconsistent.
In animal studies, carisoprodol reduced fetal weights, postnatal weight gain, and postnatal survival at maternal doses equivalent to 1 to 1.5 times the human dose (based on a body surface area comparison). Rats exposed to meprobamate in-utero showed behavioral alterations that persisted into adulthood. For children exposed to meprobamate in-utero, one study found no adverse effects on mental or motor development or IQ scores. Carisoprodol should be used during pregnancy only if the potential benefit justifies the risk to the fetus.
Aspirin: Teratogenic effects
Prior to 30 weeks gestation, aspirin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Starting at 30 weeks gestation, aspirin should be avoided by pregnant women as premature closure of the fetal ductus arteriosus which may result in fetal pulmonary hypertension and fetal death. Salicylate products have also been associated with alterations in maternal and neonatal hemostasis mechanisms, decreased birth weight, increased incidence of intracranial hemorrhage in premature infants, stillbirths, and neonatal death. Studies in rodents have shown salicylates to be teratogenic when given in early gestation, and embryocidal when given in later gestation in doses considerably greater than usual therapeutic doses in humans.
Labor and Delivery
Carisoprodol: There is no information about the effects of carisoprodol on the mother and the fetus during labor and delivery.
Aspirin: Ingestion of aspirin within one week of delivery or during labor may prolong delivery or lead to excessive blood loss in the mother, fetus, or neonate. Prolonged labor due to prostaglandin inhibition has been reported with aspirin use.
Carisoprodol: Very limited data in humans show that carisoprodol is present in breast milk and may reach concentrations two to four times the maternal plasma concentrations. In one case report, a breast-fed infant received about 4 to 6% of the maternal daily dose through breast milk and experienced no adverse effects. However, milk production was inadequate and the baby was supplemented with formula. In lactation studies in mice, female pup survival and pup weight at weaning were decreased. This information suggests that maternal use of carisoprodol may lead to reduced or less effective infant feeding (due to sedation) and/or decreased milk production. Caution should be exercised when carisoprodol is administered to a nursing woman.
Aspirin: Nursing mothers should avoid the use of aspirin because salicylate is excreted in breast milk which may lead to bleeding in the infant.
The efficacy, safety, and pharmacokinetics of Soma Compound (carisoprodol and aspirin) in pediatric patients less than 16 years of age have not been established.
The efficacy, safety, and pharmacokinetics of Soma Compound (carisoprodol and aspirin) in patients over 65 years old have not been established.
Last reviewed on RxList: 12/9/2009
This monograph has been modified to include the generic and brand name in many instances.
Additional Soma Compound Information
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