Which of the following is a pro-drug: September 2005

Ans. B: Enalapril Few drugs are inactive as such and need conversion in the body to one or more active metabolites. Such drug is called a prodrug. Carisoprodol is metabolized into meprobamate. Enalapril is conveed by esterase to the active enalaprilat. Acyclovir is conveed into the active acyclovir triphosphate. Fosamprenavir is hydrolysed to the active amprenavir. Levodopa is conveed by DOPA decarboxylase to the active dopamine. Chloramphenicol succinate ester is used as an intravenous prodrug of chloramphenicol, because pure chloramphenicol does not dissolve in water. Psilocybin is dephosphorylated to the active psilocin. Heroin is deacetylated by esterase to the active morphine. Codeine is demethylated by the liver enzyme CYP2D6 to the active morphine, as well as several other compounds that may be active in analgesia. Molsidomine is metabolized into SIN-1 which decomposes into the active compound nitric oxide. Paliperidone is an atypical antipsychotic for schizophrenia. It is the active metabolite of risperidone. Prednisone, a synthetic coico-steroid drug, is conveed by the liver into the active drug prednisolone, which is also a steroid. Primid one is metabolized by cytochrome P450 enzymes into phenobarbital, which is major and phenylethylmalonamide, which is minor. Dipivefrine, given topically as an anti-glaucoma drug, is conveed to epinephrine. Lisdexamfetamine is metabolized in the small intestine to produce dextroamphetamine at a controlled (slow) rate for the treatment of attention-deficit hyperactivity disorder Diethylpropion is a diet pill that does not become active as a monoamine releaser or reuptake inhibitor until it has been N-dealkylated to ethylpropion. Fesoterodine is an antimuscarinic that is conveed to tolterodine. Alpha-methyldopa is conveed into alpha-methylnorepinephrine. Sulindac is conveed into sulfide metabolite. Proguanil is conveed into cycloguanil.