COMTAN

What it is

Comtan is a tablet containing entacapone . Each tablet contains 200 mg entacapone . Entacapone belongs to a new therapeutic class, the catechol-O-methyl transferase (COMT) inhibitors, and is a reversible, specific, and mainly peripherally acting COMT inhibitor designed for concomitant administration with levodopa preparations .

Approved indications

— Management of Parkinson's disease as an adjunct to levodopa/dopa decarboxylase inhibitor therapy in patients who are experiencing motor fluctuations .

Dosing overview

The starting dose is one 200 mg tablet taken with each levodopa/dopa decarboxylase inhibitor dose . On average 4 to 7 doses daily are used in patients with moderate or severe Parkinson's disease . The same dosage is used in all adults, including elderly patients . The maintenance dose of Comtan is the same as the starting dose . The maximum recommended dose is 2000 mg (that is, 10 doses) daily . Entacapone enhances the effects of levodopa; to reduce levodopa-related dopaminergic adverse reactions (such as dyskinesias, nausea, vomiting and hallucinations) it is often necessary to adjust levodopa dosage within the first few days to first few weeks after initiating treatment with Comtan, with the daily dose of levodopa reduced by about 10 to 30% by extending the dosing intervals and/or by reducing the amount of levodopa per dose .

Key safety warnings

Rhabdomyolysis secondary to severe dyskinesias or neuroleptic malignant syndrome (NMS) has been observed rarely in patients with Parkinson's disease, with isolated cases of rhabdomyolysis reported with entacapone treatment . Isolated cases of NMS have been reported, especially following abrupt reduction or discontinuation of Comtan and other dopaminergic medications; withdrawal of Comtan and other dopaminergic treatment should proceed slowly and, if signs and/or symptoms occur despite a slow withdrawal of Comtan, an increase in levodopa dosage may be necessary . Entacapone therapy should be administered with caution to patients with ischaemic heart disease . Prolonged or persistent diarrhoea suspected to be related to entacapone may be a sign of colitis; in the event of prolonged or persistent diarrhoea, entacapone should be discontinued and appropriate medical therapy and investigations considered . Patients should be regularly monitored for the development of impulse control disorders, and patients and caregivers should be made aware that behavioural symptoms of impulse control disorders including pathological gambling, increased libido, hypersexuality, compulsive spending or buying, binge eating and compulsive eating can occur in patients treated with dopamine agonists and/or other dopaminergic treatments such as entacapone in association with levodopa . Comtan in association with levodopa has been associated with somnolence and episodes of sudden sleep onset in patients with Parkinson's disease; therefore, caution should be exercised when driving or operating machinery .

Contraindications

Known hypersensitivity to entacapone or any other components of the formulation is contraindicated. Pregnancy and breast feeding are contraindicated . Hepatic impairment is contraindicated . Patients with phaeochromocytoma are contraindicated due to the increased risk of hypertensive crisis . Concomitant use of Comtan with non-selective monoamine oxidase (MAO-A and MAO-B) inhibitors (such as phenelzine, tranylcypromine) is contraindicated; similarly, concomitant use of a selective MAO-A inhibitor plus a selective MAO-B inhibitor and Comtan is contraindicated . A previous history of neuroleptic malignant syndrome (NMS) and/or non-traumatic rhabdomyolysis is contraindicated .

PBS listing

Comtan tablets 200 mg are listed on the PBS with 2 items, restriction type: restricted, and ex-manufacturer price A$75.63 .

Regulatory history

Comtan entacapone 200 mg tablets were first listed on the ARTG on 12 May 1999 . The medicine received its first approval on 19 December 2003 .