The pharmacokinetics of meprobamate following its oral and rectal administration as a series of combinations with diphenhydramine, acetylsalicylic acid, codeine and pentaerythritol tetranitrate.

Studies in human volunteers of the pharmacokinetics of the active drugs in the formulations Visano-mini (meprobamate and diphenhydramine HCl), DoloVisano (meprobamate, diphenhydramine HCl, acetylsalicylic acid and codeine phosphate) and VisanoCor (meprobamate, diphenhydramine HCl and pentaerythritol tetranitrate (PETN], have demonstrated systemic absorption of each of the drugs from all of the formulations. Bioequivalence of meprobamate is indicated despite the drug combinations involved. Some differences in diphenhydramine pharmacokinetics are, however, apparent. The bioavailability of meprobamate administered rectally to human volunteers as the marketed preparations DoloVisano Suppositories and Dolo-Visano Suppositories sine codeino, is similar to that observed following oral administration.