SOMA COMPOUND W/ CODEINE
Clinical safety rating: avoid
CNS depressants including alcohol and benzodiazepines increase sedation risk Life-threatening respiratory depression may occur especially in CYP2D6 ultra-rapid metabolizers.
Soma Compound with Codeine is a combination of carisoprodol, aspirin, and codeine. Carisoprodol is a centrally acting skeletal muscle relaxant whose exact mechanism is unknown, but it is believed to act via interneuronal depression in the spinal cord and reticular formation. Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis. Codeine is an opioid agonist that binds to mu-opioid receptors in the CNS, altering pain perception.
| Metabolism | Carisoprodol is hepatically metabolized via CYP2C19 to meprobamate. Aspirin is hydrolyzed to salicylic acid and conjugated in the liver. Codeine is metabolized by CYP3A4 to norcodeine, CYP2D6 to morphine, and other pathways. |
| Excretion | Carisoprodol is hepatically metabolized; approximately 60-70% of a dose is excreted renally as meprobamate and other metabolites, with less than 1% unchanged. Codeine is renally excreted as codeine (5-17%), morphine (10-15%), and conjugates (up to 70%). Biliary/fecal elimination is minimal. |
| Half-life | Carisoprodol: 1-2 hours. Meprobamate (active metabolite): 10-12 hours. Codeine: 2.5-3.5 hours; prolonged in renal impairment. Clinical context: steered by meprobamate half-life for repeated dosing. |
| Protein binding | Carisoprodol: 60% (primarily albumin). Codeine: 7-25% (mainly albumin). |
| Volume of Distribution | Carisoprodol: Vd ~2.5 L/kg; indicates extensive tissue distribution. Codeine: Vd ~3-6 L/kg; high tissue binding. |
| Bioavailability | Oral: carisoprodol 90-100%; codeine 50-90% (first-pass metabolism). |
| Onset of Action | Oral: carisoprodol 30 minutes; codeine 30-60 minutes. |
| Duration of Action | Carisoprodol: 4-6 hours. Codeine: 4-6 hours. Clinical notes: prolonged with higher doses or hepatic/renal dysfunction. |
1-2 tablets (carisoprodol 200 mg / aspirin 325 mg / codeine phosphate 16 mg) orally every 4-6 hours as needed for pain, not to exceed 4 tablets per day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: Avoid use due to aspirin component; if necessary, reduce dose by 50% and monitor for toxicity. GFR <30 mL/min: Contraindicated due to risk of aspirin accumulation and codeine metabolite accumulation. |
| Liver impairment | Child-Pugh Class A: No adjustment recommended, but use with caution. Child-Pugh Class B: Reduce dose by 50% due to impaired metabolism of codeine and carisoprodol; monitor for sedation and respiratory depression. Child-Pugh Class C: Avoid use due to high risk of toxicity. |
| Pediatric use | Not recommended for pediatric use due to risk of Reye's syndrome (aspirin) and respiratory depression (codeine); contraindicated in children <12 years for codeine; avoid in all pediatric patients. |
| Geriatric use | Start at lower dose (1 tablet every 6-8 hours) due to increased sensitivity to CNS effects and renal impairment; monitor for sedation, falls, and gastrointestinal bleeding (aspirin). |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
CNS depressants including alcohol and benzodiazepines increase sedation risk Life-threatening respiratory depression may occur especially in CYP2D6 ultra-rapid metabolizers.
| FDA category | Positive |
| Breastfeeding | Both codeine and carisoprodol are excreted into breast milk. Codeine: M/P ratio ~1.5, risk of infant sedation and respiratory depression, especially in CYP2D6 ultra-rapid metabolizers. Carisoprodol: M/P ratio not well defined, but considered present. Contraindicated during breastfeeding due to potential for infant opioid toxicity and sedation. |
| Teratogenic Risk |
■ FDA Black Box Warning
Concomitant use of codeine with all CYP3A4 inducers may lead to withdrawal symptoms or reduced efficacy. Concomitant use with CYP3A4 inhibitors may increase codeine plasma concentrations and prolong adverse reactions. Codeine is contraindicated in children younger than 12 years and in children younger than 18 years following tonsillectomy and/or adenoidectomy due to risk of respiratory depression and death. Avoid use in adolescents with risk factors for respiratory depression.
| Common Effects | cough |
| Serious Effects |
Hypersensitivity to any component, acute porphyria (carisoprodol), children <12 years, post-tonsillectomy/adenoidectomy in children <18 years, significant respiratory depression, acute or severe bronchial asthma, GI obstruction, suspected surgical abdomen, bleeding disorders (aspirin), concomitant use of MAOIs, use within 14 days of MAOIs.
| Precautions | Risk of respiratory depression, drug dependence, abuse potential, impaired mental/physical abilities, severe hepatic injury from aspirin, Reye syndrome in children, anaphylaxis, bleeding risk (aspirin), serotonin syndrome (concomitant serotonergic drugs), adrenal insufficiency, severe hypotension, seizure risk, withdrawal with discontinuation. |
Loading safety data…
| First trimester: Risk of neural tube defects and congenital malformations associated with codeine (FDA Pregnancy Category D). Carisoprodol: limited data, but caution due to potential metabolic effects. Second and third trimesters: Chronic use of codeine may lead to fetal opioid dependence and neonatal abstinence syndrome (NAS). Carisoprodol may cause fetal respiratory depression and withdrawal. |
| Fetal Monitoring | Monitor for fetal distress, growth restriction, and signs of NAS. Maternal: respiratory rate, sedation level, and signs of opioid toxicity. Consider fetal non-stress testing and biophysical profile in chronic use. |
| Fertility Effects | Codeine may increase prolactin levels causing menstrual irregularities and reduced fertility. Carisoprodol: limited data, but potential for hormonal disruption due to chronic use. Both may impair reproductive function with long-term use. |