Carisoprodol is a muscle relaxer that works by blocking pain sensations between the nerves and the brain. Carisoprodol is used together with rest and physical therapy to treat injuries and other painful musculoskeletal conditions. SOMA (carisoprodol) Tablets are available as 250 mg and 350 mg round, white tablets. Carisoprodol is a white, crystalline powder, having a mild, characteristic odor and a bitter taste. It is slightly soluble in water; freely soluble in alcohol, in chloroform, and in acetone; and its solubility is practically independent of pH. Carisoprodol is present as a racemic mixture. Chemically, carisoprodol is N-isopropyl-2-methyl-2-propyl-1,3-propanediol dicarbamate and the molecular formula is C12H24N2O4, with a molecular weight of 260.33. The structural formula is:
SOMA is indicated for the relief of discomfort associated with acute, painful musculoskeletal conditions in adults.
SOMA should only be used for short periods (up to two or three weeks) because adequate evidence of effectiveness for more prolonged use has not been established and because acute, painful musculoskeletal conditions are generally of short duration
What should I discuss with my healthcare provider before taking carisoprodol?
Do not use this medication if you are allergic to carisoprodol or meprobamate (Equanil, Miltown), or if you have porphyria.
Before using this medication, tell your doctor if you are allergic to any drugs, or if you have:
- epilepsy or other seizure disorder;
- liver disease; or
- kidney disease.
If you have any of these conditions, you may need a dose adjustment or special tests to safely take carisoprodol.
This medication may be habit-forming and should be used only by the person it was prescribed for. Carisoprodol should never be given to another person, especially someone who has a history of drug abuse or addiction. Keep the medication in a secure place where others cannot get to it. You may have withdrawal symptoms when you stop using carisoprodol after using it over a long period of time. Withdrawal symptoms include stomach pain, sleep problems, headache, nausea, and seizure (convulsions). Do not stop using this medication suddenly without first talking to your doctor. You may need to use less and less before you stop the medication completely. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether carisoprodol passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby. Do not give this medication to a child younger than 12 years old..
HOW Carisoprodol SUPPLIED
Dosage Forms And Strengths
250 mg Tablets: round, convex, white tablets, inscribed with SOMA 250
350 mg Tablets: round, convex, white tablets, inscribed with SOMA 350
Storage and Handling
250 mg Tablets: round, convex, white tablets, inscribed with SOMA 250; available in bottles of 100 (NDC 0037-2250-10) and bottles of 30 (NDC 0037-2250-30).
350 mg Tablets: round, convex, white tablets, inscribed with SOMA 350; available in bottles of 100 (NDC 0037-2001-01).
Carisoprodol side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using carisoprodol and call your doctor at once if you have any of these serious side effects:
- paralysis (loss of feeling);
- extreme weakness or lack of coordination;
- feeling light-headed, fainting;
- fast heartbeat;
- seizure (convulsions);
- vision loss; or
- agitation, confusion.
Less serious side effects may include:
- drowsiness, dizziness, tremor;
- headache;
- depression, feeling irritable;
- blurred vision;
- sleep problems (insomnia); or
- nausea, vomiting, hiccups, upset stomach.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
Carisoprodol DRUG INTERACTIONS
CNS Depressants
The sedative effects of SOMA and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants) may be additive. Therefore, caution should be exercised with patients who take more than one of these CNS depressants simultaneously. Concomitant use of SOMA and meprobamate, a metabolite of SOMA, is not recommended .
CYP2C19 Inhibitors and Inducers
Carisoprodol is metabolized in the liver by CYP2C19 to form meprobamate. Co-administration of CYP2C19 inhibitors, such as omeprazole or fluvoxamine, with SOMA could result in increased exposure of carisoprodol and decreased exposure of meprobamate. Co-administration of CYP2C19 inducers, such as rifampin or St. John’s Wort, with SOMA could result in decreased exposure of carisoprodol and increased exposure of meprobamate. Low dose aspirin also showed an induction effect on CYP2C19. The full pharmacological impact of these potential alterations of exposures in terms of either efficacy or safety of SOMA is unknown.
Drug Abuse And Dependence
SOMA is not a controlled substance. Discontinuation of carisoprodol in animals or in humans after chronic administration can produce withdrawal signs, and there are published case reports of human carisoprodol dependence.
In vitro studies demonstrate that carisoprodol elicits barbiturate-like effects. Animal behavioral studies indicate that carisoprodol produces rewarding effects. Monkeys self administer carisoprodol. Drug discrimination studies using rats indicate that carisoprodol has positive reinforcing and discriminative effects similar to barbital, meprobamate, and chlordiazepoxide.
Use In Specific Population
Pregnancy: Pregnancy Category C.
There are no data on the use of SOMA 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.
Teratogenic effects
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.
Nonteratogenic effects
In animal studies, carisoprodol reduced fetal weights, postnatal weight gain, and postnatal survival at maternal doses equivalent to 1-1.5 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. SOMA should be used during pregnancy only if the potential benefit justifies the risk to the fetus.
Labor and Delivery
There is no information about the effects of SOMA on the mother and the fetus during labor and delivery.
Nursing Mothers
Very limited data in humans show that SOMA 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 4-6% 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 SOMA may lead to reduced or less effective infant feeding (due to sedation) and/or decreased milk production. Caution should be exercised when SOMA is administered to a nursing woman.
Pediatric Use
The efficacy, safety, and pharmacokinetics of SOMA in pediatric patients less than 16 years of age have not been established.
Geriatric Use
The efficacy, safety, and pharmacokinetics of SOMA in patients over 65 years old have not been established.
Renal Impairment
The safety and pharmacokinetics of SOMA in patients with renal impairment have not been evaluated. Since SOMA is excreted by the kidney, caution should be exercised if SOMA is administered to patients with impaired renal function. Carisoprodol is dialyzable by hemodialysis and peritoneal dialysis.
Hepatic Impairment
The safety and pharmacokinetics of SOMA in patients with hepatic impairment have not been evaluated. Since SOMA is metabolized in the liver, caution should be exercised if SOMA is administered to patients with impaired hepatic function.
Patients with Reduced CYP2C19 Activity
Patients with reduced CYP2C19 activity have higher exposure to carisoprodol. Therefore, caution should be exercised in administration of SOMA to these patients