Opicapone (Ongentys) is an adjunctive therapeutic drug for Parkinson’s disease (PD). As a combination therapy with levodopa/carbidopa, it is indicated to reduce the occurrence of wearing-off phenomena in patients. Like all medications, understanding its potential adverse reactions and essential precautions is crucial for its safe and effective administration.

Adverse Reactions of Opicapone (Ongentys)

Common Adverse Reactions

Dyskinesia.

Constipation.

Elevated blood creatine kinase.

Hypotension/syncope.

Weight loss.

Serious Adverse Reactions.

Cardiovascular System Effects

Opicapone is a catechol-O-methyltransferase (COMT) inhibitor.

Concomitant use with other drugs metabolized by COMT (e.g., isoprenaline, adrenaline, noradrenaline, dopamine, dobutamine) may trigger arrhythmias, tachycardia and excessive blood pressure fluctuations.

When such combined medication is adopted, close monitoring of the patient’s heart rate, cardiac rhythm and blood pressure changes is required.

Excessive Daytime Sleepiness and Sudden Onset of Sleep

Patients receiving dopaminergic therapy (including opicapone) may experience sudden sleep onset during routine activities (e.g., driving, operating machinery, conversing), often without prior feelings of drowsiness or warning signs.

This condition may lead to accidental injuries. Prior to initiating treatment, physicians should assess patients for risk factors such as pre-existing sleep disorders or concurrent use of other sedating medications.

If daytime sleepiness or sleep episodes occur during alertness-required activities, discontinuation of opicapone or dosage adjustment of other medications should be considered. Affected patients must avoid driving and engaging in hazardous activities.

Abnormal Involuntary Movements (Dyskinesia)

Opicapone potentiates the effects of levodopa, which may induce or exacerbate pre-existing dyskinesia.

In clinical studies, this was one of the most common adverse reactions of opicapone and also the leading cause of treatment discontinuation.

For severe or distressing dyskinesia, reduction of the daily dosage of levodopa or other dopaminergic drugs should be considered.

Precautions for Opicapone (Ongentys) Administration

Contraindications

Concurrent use with non-selective monoamine oxidase inhibitors (e.g., phenelzine, isocarboxazid, tranylcypromine) is prohibited.

It is contraindicated in patients with a history of pheochromocytoma, paraganglioma or other catecholamine-secreting tumors.

Administration and Dietary Requirements

Dosage and Administration: The recommended dosage is 50 mg once daily, to be taken at bedtime.

Dietary Restrictions: Food intake should be avoided for 1 hour before and at least 1 hour after administration, as food can significantly reduce drug absorption.

Missed Dose Management: If a dose is missed, the regular daily dose should be taken at the scheduled time on the following day. Do not take a double dose or make up for the missed dose.

Drug Interactions

Special attention should be paid to interactions with COMT-metabolized drugs and non-selective MAO inhibitors.

Concomitant use with selective MAO-B inhibitors (e.g., selegiline, rasagiline) is generally considered safe.