<prompt> Which of the following agents enhances the bioavailability of levodopa -AmantadineRopiniroleEntacaponeSelegiline  <response>: Ans. is c i.e., Entacapone o When peripheral decarboxylation of levodopa is blocked by carbidopabenserazide, it is mainly metabolized by COMT to 3-0-methyldopa. o Blockade of this pathway by entacaptonetolcapone fuher prolongs the t 12 of levodopa and allows a larger fraction of administered dose to cross to brain. 