Carisoprodate; Isobamate; Isopropyl meprobamate.
· Carisoprodol is related structurally and pharmacologically to meprobamate and is a CNS depressant with muscle relaxant properties.
· It is usually used as an adjunct to analgesics in the relief of acute musculoskeletal pain.
· Blood levels of over 30 mcg/ml are associated with toxicity.
· Overdose results in drowsiness, lethargy, vertigo, diplopia, nystagmus, headache, ataxia, tachycardia, convulsions, and coma.
· Horizontal and vertical nystagmus, mydriasis and blurred vision may occur.
· Sinus tachycardia with a prolonged QT interval has been reported.
· Death can occur. Survival may be associated with amnesia relating to events during the course of toxicity.
· Chronic therapeutic use may cause skin rash, drowsiness, nausea, vertigo, ataxia, tremor and headache.
· Sudden cessation of chronic therapy can cause a with-drawal reaction: anxiety, tremors, muscle twitching, insomnia, auditory and visual hallucinations, bizarre behaviour.
· Stomach wash if the patient is seen within 3 to 4 hours, activated charcoal, and cathartics.
· Supportive measures usually suffice to reverse the toxic effects.
· Flumazenil has been used with beneficial effects (0.2 mg IV, repeated as required).