Entacapone

Indications

Entacapone is used for: Parkinson's disease

Adult Dose

Oral Adjunct to levodopa treatment in Parkinson's disease Adult: 200 mg w/ each levodopa/dopa decarboxylase inhibitor dose. Max: 200 mg 10 times daily (2,000 mg daily). Hepatic Impairment Safety and efficacy not established

Child Dose

Renal Dose

Renal Impairment Dose adjustment not necessary

Administration

May be taken with or without food.

Contra Indications

History of neuroleptic malignant syndrome and nontraumatic rhabdomyolysis. Phaeochromocytoma. Hepatic impairment.

Precautions

Levodopa-induced orthostatic hypotension may be aggravated. Abrupt withdrawal. Concomitant use with a selective MAO-A and MAO-B inhibitor, or concomitant use with a selective MAO-A plus a selective MAO-B inhibitor. Biliary obstruction. Impairs ability to drive and operate machinery. Pregnancy and lactation. Children and elderly. Lactation: excretion in milk unknown; use with caution

Pregnancy-Lactation

Pregnancy Category: C Lactation: excretion in milk unknown; use with caution

Interactions

Drugs metabolised by COMT e.g. adrenaline, apomorphine, dobutamine, dopamine, isoprenaline, methyldopa, noradrenaline and remiterol. Iron preparations and levodopa. Avoid ethanol.

Adverse Effects

Side effects of Entacapone : >10% Dyskinesia (25%), Nausea (14%), Diarrhea (10%), Hyperkinesia (10%), Urine discoloration (10%) 1-10% Hypokinesia (9%), Dizziness (8%), Abdominal pain (8%), Fatigue (6%), Constipation (6%), Back pain (4%), Vomiting (4%), Dry mouth (3%), Dyspnea (3%), Increased sweating (2%), Back pain (2%), Anxiety (2%), Somnolence (2%), Dyspepsia (2%), Flatulence (2%), Purpura (2%), Asthenia (2%), Hallucinations (1-4%), Taste perversion (1%), Agitation (1%), Gastritis (1%), Bacterial infection (1%) Frequency Not Defined Insomnia, Postural hypotension, Confusion, Dopaminergic side affects due to increased dopamine levels Rare: rhabdomyolysis, retroperitoneal fibrosis

Mechanism of Action

Entacapone is a selective, reversible, peripheral inhibitor of COMT, an enzyme involved in the metabolism of dopamine and levodopa. It is used in patients with Parkinson's disease and "end-of-dose" motor fluctuations that cannot be stabilised on levodopa combinations alone.