Entacapone

• Parkinson’s disease

Adjunct to levodopa treatment in Parkinson's disease

N/A

Phaeochromocytoma, history of neuroleptic malignant syndrome and/or non-traumatic rhabdomyolysis. Hepatic impairment. Concomitant use w/ non-selective MAOIs.

Entacapone decreases the metabolic loss of levodopa to 3-O-methyldopa (3-OMD) through inhibition of COMT enzyme leading to an increased levodopa concentration, thus, extending the duration and effect in the brain.

May interfere with metabolism of other drugs metabolised by COMT (e.g. rimiterole). May aggravate levodopa-induced orthostatic hypotension. Risk of dopaminergic effects with dopamine agonists (e.g. bromocriptine), selegiline, amantadine. May form chelates with Fe in the GI tract. Additive sedative effects with other CNS depressants.

Abdominal pain, nausea, vomiting, diarrhoea, constipation, colitis, dry mouth, dyskinesia, dizziness, nightmares, insomnia, hallucinations, confusion, fatigue, increased sweating, behavioural disturbances; urine, skin, hair, beard and nail discolourations; cholestatic hepatitis, rhabdomyolysis. Rarely, agitation, urticaria, erythematous or maculopapular rash, anorexia, wt decrease, increased liver enzymes.

Symptoms: Decreased activity, confusion, somnolence, hypotonia, urticaria, skin discolouration. Management: Symptomatic treatment.

Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.

Patient with biliary obstruction, ischaemic heart disease. Avoid abrupt withdrawal. Pregnancy and lactation.