Indications for COMTAN:
Adjunct to levodopa/ carbidopa in patients with idiopathic Parkinson's disease and end-of-dose wearing off.
200mg with each dose of levodopa/carbidopa, up to 8 times daily.
Dyskinesias. Pre-existing somnolence or sleep disorders. Major psychotic disorder: not recommended. Impulse control disorders; consider dose reduction or discontinue if occurs. Perform skin exams to monitor for melanoma. Discontinue if prolonged diarrhea suspected. Hepatic impairment. Biliary obstruction. Avoid abrupt cessation. Pregnancy (Cat.C). Nursing mothers.
Nonselective MAOIs: not recommended. Consider reducing levodopa dose. Potentiates CNS depression with alcohol, other CNS depressants. Chelates iron. Cardiac effects with drugs metabolized by COMT (eg, epinephrine, isoproterenol, norepinephrine, dopamine, dobutamine, methyldopa, apomorphine, isoetherine, bitolterol). Caution with drugs that interfere with biliary excretion, glucuronidation, intestinal beta-glucuronidase (eg, probenecid, cholestyramine, erythromycin, rifampicin, ampicillin, chloramphenicol). Monitor INR with warfarin. Reduced efficacy with some antipsychotics.
Dyskinesia, nausea, urine discoloration, hyperkinesia, diarrhea, abdominal pain, vomiting, dry mouth, back pain, dyspnea, somnolence, anxiety, sweating, purpura, asthenia, taste perversion; rarely: orthostatic hypotension, syncope, hallucinations, rhabdomyolysis, hyperpyrexia and confusion upon withdrawal.