<prompt> Anti-Parkinsonism drug that is a selective COMT inhibitorEntacaponeRopinirolePergolidePramipexole  <response>: Inhibitors of COMT increase the elimination half-life of levodopa and enhance its brain availability. Combining levodopa with a COMT inhibitor reduces off time and prolongs on time in fluctuating patients while enhancing motor scores. Two COMT inhibitors have been approved, tolcapone and entacapone. Reference: Harrisons Principles of Internal Medicine; 19th edition; Chapter 449; Parkinsons Disease and Other Movement Disorders 