Carisoprodol (Soma 350 mg) Urine Detection Window

Carisoprodol (Soma) is a centrally acting muscle relaxant metabolized to meprobamate (active, long‑half‑life anxiolytic).

Detection in Urine

• Parent drug (carisoprodol): 24–48 hours.
• Metabolite (meprobamate): 2–4 days (up to 5–7 days in chronic use).
• Standard immunoassay panels: Often detect meprobamate (cross‑reactivity with barbiturate assay) or specific carisoprodol/meprobamate LC‑MS/MS.

Factors Influencing Window

• Age, hydration, urine pH, renal function.
• Chronic dosing → accumulation of meprobamate (t½ ~10 h) → longer detection.
• CYP2C19 poor metabolizers → higher carisoprodol, lower meprobamate.

Clinical & Legal Notes

• Schedule IV controlled substance (US).
• Prescribed use: Provide prescription documentation to MRO.
• False positives: Rare; confirmatory GC‑MS/LC‑MS/MS eliminates.

Typical window for a single 350 mg dose: Positive for meprobamate 2–4 days; carisoprodol itself often undetectable by 24h.