Entacapone

When should one not use Entacapone

• If you are allergic to entacapone or any of the other ingredients of this medicine.
• If you have liver problems or severe hepatic impairment.
• If you have a tumour called pheochromocytoma.
• If you are taking non-selective MAO inhibitors (e.g., phenelzine, tranylcypromine) at the same time as Entacapone.
• If you are taking a combination of selective MAO-A and MAO-B inhibitors with Entacapone.
• If you have a history of neuroleptic malignant syndrome (NMS) or unexplained muscle breakdown (rhabdomyolysis).

Common side effects of this drug are:

• Nausea
• Diarrhoea
• Abdominal pain
• Dry mouth
• Constipation
• Vomiting

Other General Warnings

• You have a history of muscle breakdown (rhabdomyolysis) or neuroleptic malignant syndrome (NMS).
• You have heart problems, including ischaemic heart disease or low blood pressure when standing (orthostatic hypotension).
• You are taking medicines that affect catecholamines (e.g., adrenaline, dopamine, dobutamine, alpha-methyldopa, apomorphine).
• You are on levodopa or other Parkinson's medicines, as dose adjustments may be needed to reduce side effects.
• You experience severe or persistent diarrhoea, as this may indicate colitis or lead to excessive weight loss.
• You develop impulse control problems, such as compulsive gambling, increased sexual drive, binge eating, or compulsive shopping.
• You experience rapid weight loss, loss of appetite, or general weakness, liver function and overall health should be assessed.
• You have a rare sugar-metabolism disorder (e.g., fructose intolerance, glucose-galactose malabsorption, sucrase-isomaltase deficiency), as this medicine contains sucrose.
• You feel very sleepy or suddenly fall asleep during the day, you should avoid driving or operating machinery.

How Does It Work?

Interactions with other medicines

• No interactions have been observed between Entacapone and carbidopa at the recommended doses. Interaction with benserazide has not been studied.
• No significant interactions were seen in studies with imipramine, moclobemide, or selegiline, though caution is advised when combining Entacapone with MAO-A inhibitors, tricyclic antidepressants, noradrenaline reuptake inhibitors (e.g., desipramine, maprotiline, venlafaxine), or catechol-based medicines (e.g., rimiterol, isoprenaline, adrenaline, noradrenaline, dopamine, dobutamine, alpha-methyldopa, apomorphine, paroxetine).
• Entacapone can be used with selegiline (a selective MAO-B inhibitor) if the daily dose of selegiline does not exceed 10 mg.
• Entacapone may bind to iron in the gut; take iron supplements at least 2–3 hours apart from this medicine.
• Entacapone may bind to the same protein sites as medicines like diazepam or ibuprofen, but no significant interactions are expected at normal doses.
• Entacapone may slightly affect medicines metabolized by CYP2C9, such as warfarin; blood clotting tests (INR) should be monitored when starting Entacapone.

Interactions with food items

• Avoid taking Entacapone concurrently with iron supplements, as it can reduce absorption; leave at least 2–3 hours between them.
• There are no significant interactions with other foods, but maintaining a balanced diet supports overall treatment effectiveness.
• Drink adequate water while taking Entacapone to help absorption and reduce digestive discomfort.
• Grapefruit or grapefruit juice is not expected to significantly affect Entacapone, but it's generally better to avoid large amounts of grapefruit with any Parkinson's medications.

Overdose

Missed a Dose