Entacapone

Indications

Adjunct to levodopa treatment in Parkinson's disease

Pharmacology

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.

Dosage And Administration

200 mg with each levodopa/dopa decarboxylase inhibitor dose. Max: 200 mg 10 times daily (2,000 mg daily). Gradually reduce levodopa dose by approx 10-30% or increase dosing interval w/in the 1st few wk of starting treatment.

May be taken with or without food.

* চিকিৎসকের পরামর্শ মোতাবেক ঔষধ সেবন করুন'

Interaction

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.

Contraindications

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

Side Effects

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.

Pregnancy And Lactation

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.

Precautions And Warnings

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

Overdose Effects

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