Generic Name

Soma

Mechanism

• Central nervous system depressant that potentiates *GABA* activity.
• Likely acts by inhibiting the *GABA*‑binding protein α5 subunit, leading to decreased excitatory neuronal firing.
• Metabolized to the active moiety *meprobamate*, which enhances GABA‑A receptor chloride conductance and exerts muscle relaxant, anxiolytic, and mild sedative effects.

Pharmacokinetics

Indications

• Short‑term alleviation of acute muscle pain and spasm.
• Adjunct to physiotherapy and exercise programs.
• Not approved for chronic back pain or long‑term use.

Contraindications

• History of hypersensitivity to carisoprodol or meprobamate.
• Severe pulmonary disease, acute glaucoma, or myasthenia gravis – may worsen symptoms.
• Pregnancy Category C – limited data; avoid unless benefits > risks.
• Liver or renal impairment → dose adjustment; caution in severe dysfunction.
• Concurrent use with other CNS depressants → heightened respiratory depression.

Warnings
• Potential for abuse, dependence, and withdrawal.
• Rare reports of *meprobamate* withdrawal symptoms (anxiety, agitation).
• Re‑exposure risks: 30–40 % relapse within 3 months after discontinuation.

Dosing

• Administer with food if GI intolerance occurs.
• For acute pain, may give 50 mg q6h for 48–72 h; extend only upon specialist review.
• Tapering: 12–24 h after last dose, then reassess for withdrawal symptoms.

Adverse Effects

Common (≥ 5 %)
• Drowsiness, dizziness, blurred vision.
• Gastro‑intestinal upset (nausea, dyspepsia).
• Tremor or muscle weakness.

Serious
• Respiratory depression (esp. with opioids or alcohol).
• Hypotension, orthostatic fall.
• Severe allergic reactions (rash, angioedema).
• Hepatotoxicity (rare; jaundice, ↑ALT/AST).
• Dependence, abuse potential (meprobamate).

Monitoring

• Vitals: BP, HR, respiratory rate (especially with CNS depressants).
• Liver function tests: baseline, then every 4 weeks if prolonged therapy.
• Renal function: baseline, especially in CKD or elderly.
• Withdrawal assessment: monitor for anxiety, insomnia, tremor after cessation.
• Pregnancy tests in women of childbearing age where clinically indicated.

Clinical Pearls

1. Meprobamate‑driven abuse – be alert for the “Soma” side‑effect profile: mild euphoria, impaired judgment, and rapid tolerance buildup.

2. First‑line vs. adjunct – Use *Soma* only as a short‑term adjunct. Long‑term functional improvement relies on physical therapy, NSAIDs, and core strengthening.

3. Drug‑interaction red flag – The combination of *Soma* with benzodiazepines or alcohol can precipitate life‑threatening respiratory depression; use a strict no‑alcohol policy during therapy.

4. Dose‑splitting caution – Clinicians often ask patients to divide tablets to avoid 350 mg doses. This is contraindicated; 350 mg splits can exceed safe limits and increase toxicity.

5. Withdrawal checklist – Upon discontinuation, advise patients to slowly taper over 48 h and to seek immediate care if they experience agitation, restlessness, or hallucinations.

6. Pregnancy monitoring – For women of reproductive age, counsel contraception during therapy and for at least 7 days after the last dose because *meprobamate* is cleared slowly.

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• References

1. Tripathi AK. *Basic and Clinical Pharmacology*. 15th ed.; New Delhi: McGraw‑Hill India; 2021.

2. Katzung BG, Trevor AJ. *Basic & Clinical Pharmacology*. 15th ed.; New York: McGraw‑Hill; 2020.

3. American Pharmacists Association. *Drug Information Portal – Carisoprodol*. 2024.

4. FDA Drug Safety Communication: Carisoprodol Abuse & Dependence – 2022.