Indications
Entacapone is used in adults with Parkinson’s disease who take Levodopa (with Carbidopa or Benserazide) and have “wearing-off” symptoms, where the effect of each Levodopa dose fades before the next dose is due. It is available alone and in combination tablets with Levodopa and Carbidopa.
How It Works
Entacapone blocks an enzyme called COMT (catechol-O-methyltransferase), which breaks down Levodopa in the body. With less breakdown, more Levodopa reaches the brain and its effect lasts longer, giving smoother control of symptoms. It has no effect on Parkinson’s disease when taken without Levodopa.
Dosage and Administration
Usual adult dose: 200 mg taken at the same time as each Levodopa dose, up to a maximum of 2,000 mg (10 tablets) a day. Combination tablets: as prescribed by the doctor. It can be taken with or without food. When entacapone is started, the doctor may need to lower the Levodopa dose to avoid extra movements or other side effects.
Interactions
- Do not take with non-selective MAO inhibitors such as Phenelzine or Tranylcypromine. Selegiline and Rasagiline may be used at their usual doses.
- Iron supplements reduce absorption; take them at least 2 to 3 hours apart.
- It can increase the effects of Adrenaline, Noradrenaline, Dopamine, Dobutamine, Isoprenaline and Apomorphine.
- It may increase the effect of Warfarin; blood clotting tests may be checked.
- Medicines that cause drowsiness add to sleepiness.
Contraindications
- Liver disease.
- Phaeochromocytoma (a tumour of the adrenal gland).
- A past history of neuroleptic malignant syndrome or non-injury muscle breakdown (rhabdomyolysis).
- Use with non-selective MAO inhibitors.
- Allergy to entacapone or any ingredient of the product.
Side Effects
Common effects are reddish-brown urine (harmless), extra uncontrolled movements (dyskinesia), nausea, diarrhoea, stomach pain, dry mouth, dizziness or light-headedness on standing, tiredness, sweating and trouble sleeping. Some people have hallucinations, confusion, sudden sleep during the day, or urges such as gambling, overeating or shopping.
Get urgent medical help for high fever with stiff muscles and confusion, severe or ongoing diarrhoea with weight loss, yellow skin or eyes, muscle pain with dark urine, or falling asleep suddenly during daily activities.
Pregnancy and Lactation
Not recommended in pregnancy unless the doctor decides it is needed. Do not breastfeed while taking it.
Precautions and Warnings
- Do not stop taking it suddenly; the doctor will reduce it slowly if needed.
- Do not drive or use machines if you feel sleepy or have had sudden sleep episodes.
- Tell the doctor about new urges or behaviour changes; family members may notice them first.
- Rise slowly from sitting or lying to reduce dizziness.
- Weight and liver tests may be checked during long-term use.
Overdose
An overdose may cause confusion, reduced activity, sleepiness, vomiting, abnormal movements and discoloured skin or urine. Seek medical help straight away.
Therapeutic Class
Antiparkinson medicine (COMT inhibitor).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.