<prompt> Mechanism of action of Tolcapone is -Dopa decarboxylase inhibitorCOMT inhibitorMAO - A inhibitorMAO - B inhibitor  <response>: Ans. is b i.e., COMT inhibitor Note: Clorgyline is a MAO A inhibitor not MAO BDrugs for parkinsonismIncreasing brain dopaminergic activityDecreasing brain cholinergic activity Dopamine precursor - Levodopa Periphera decarboxylase inhibitors - Carbidopa, Benserazide Dopaminergic agonists - Bromocriptine, Ropinirole, Pramipexal, Rotigotine MAO-B inhibitor - Selegiline COMT inhibitor - Entacapone, Tolcapone Dopamine facilitator - Amantidine Central anticholinergic - Trihexyphenidyl Benzhexol, Procyclidine, Biperiden. Antihistaminic - Orphenadrine, promethazine. MAO inhibitors1. Nonselective - Tranylcypromine, phenelzine, isocarboxazid.2. Selective MAO-A - Moclobemide, clorgyline used in depression3. Selective MAO-B - Selegiline used in parkinsonism. 