Diazepam infusion in tetanus: correlation of drug levels with effect.

A patient with muscle spasms and rigidity associated with tetanus was successfully treated with a continuous infusion of diazepam. This beneficial response was associated with a minimal serum diazepam concentration of 500 ng/ml. The major metabolite of diazepam, DMD, did not appear to exert substantial activity. Guidelines for dosing diazepam are provided.