Which of the following is a prodrug is -
(C) (Primidone) (38 - H 18th) (23, 413 - KDT 7th)PRIMIDONE - A deoxybarbiturate converted by liver to phenobarbitone and phenylethyl malonamide (PEMA). Its antiepileptic activity is mainly due to those active metabolites because t 1/2 of primidone (6-14 hr.) is less than that of its active metabolites, About 1/3 primidone is excreted unchanged by Kidney.Prodrugs are inactive compounds that require metabolism to generate active metabolites that mediate the drug effects. Examples include many angiotensin-converting enzyme (ACE) inhibitors, the angiotensin receptor blocker losartan, the antineoplastic irinotecan, the anti-estrogen tamoxifen, the analgesic codeine (whose active metabolite morphine probably underlies the opioid effect during codeine administration), and the antiplatelet drug clopidogrel. Drug metabolism has also been implicated in bioactivation of procarcinogens and in generation of reactive metabolites that mediate certain adverse drug effects (e.g., acetaminophen hepatotoxicity).ProdrugActive formLevodopa- DopamineEnalapril- Enalaprilata-Methyldopa- a-methylnorepinephrineDipivefrine- EpinephrineSulindac- Sulfide metaboliteProguanil- CycloguanilPrednisone- PrednisoloneBacampicillin- AmpicillinSulfasalazine- 5-Aminosalicylic acidCyclophosphamideAidophosphamide, phosphoramide mustard, acroleinFluorouracil- Fluorouridine monophosphateMercaptopurine- Methylmercaptopurine ribonucleotideAcyclovir- Acyclovir triphosphate
Phenytoin
Carbamazepine
Primidone
Valproic acid
General Pharmacology