Drug Monograph

Ongentys (Opicapone)

opicapone
Third-Generation Peripheral COMT Inhibitor·Oral Capsule · Once Daily
Pharmacokinetic Profile
Half-Life
1–2 h (parent); sulfate metabolite t½ 94–122 h
Metabolism
Sulfation (67%), methylation (21%); non-CYP
Protein Binding
>99%
Bioavailability
~20% (fasting); food reduces AUC by 31%
COMT Inhibition Duration
>24 h (enables once-daily dosing)
Clinical Information
Drug Class
Third-generation peripheral COMT inhibitor
Available Doses
25 mg, 50 mg capsules
Route
Oral (once daily at bedtime)
Renal Adjustment
Not required (mild–severe); avoid ESRD (CrCl <15)
Hepatic Adjustment
Moderate (Child-Pugh B): reduce to 25 mg; avoid severe (Child-Pugh C)
Pregnancy
Fetal abnormalities in animal studies (1 of 2 species); no human data
Lactation
Opicapone/metabolites in rat milk; unknown in humans
Schedule
Prescription only (not scheduled)
Generic Available
No (brand Ongentys)
Rx

Indications

IndicationApproved PopulationTherapy TypeStatus
Parkinson’s disease — adjunctive to levodopa/carbidopa in patients experiencing “off” episodesAdultsAlways adjunctive to LD/DDCIFDA Approved (2020)

Opicapone is a third-generation, peripherally selective, reversible COMT inhibitor that represents an advance over entacapone in two key respects: once-daily dosing (rather than with every levodopa dose) and more potent, sustained COMT inhibition (>24 hours). In preclinical models, opicapone achieved 99% COMT inhibition at 1 hour versus 68% for entacapone; at 9 hours, opicapone maintained 91% inhibition whereas entacapone had no detectable effect. This sustained pharmacodynamic profile reflects opicapone’s tight binding to the COMT enzyme with very slow dissociation, resulting in a COMT inhibition half-life of 60–130 hours — far exceeding the parent drug’s plasma half-life of 1–2 hours — and enabling once-daily bedtime administration.

Key Advantages Over Entacapone

Once-daily dosing (vs with each LD dose), more potent and sustained COMT inhibition, no clinically significant diarrhea or colitis risk, and no hepatotoxicity concerns. Like entacapone, no mandatory liver function monitoring is required.

Dose

Dosing

Clinical ScenarioStarting DoseMaintenance DoseMaximum DoseNotes
PD with off episodes — standard50 mg once daily at bedtime50 mg once daily50 mg/dayNo titration required; take on empty stomach
No food 1 h before and ≥1 h after dosing (food reduces AUC by 31%)
Moderate hepatic impairment (Child-Pugh B)25 mg once daily at bedtime25 mg once daily25 mg/dayAUC increased ~84% in moderate hepatic impairment (FDA PI)
Mild hepatic impairment (Child-Pugh A)50 mg once dailyStandard50 mg/dayAUC increased ~35%; not clinically significant; no adjustment
Severe hepatic impairment (Child-Pugh C)Avoid use; not studied
Renal impairment (CrCl 15–89)50 mg once dailyStandard50 mg/dayMonitor for adverse effects in severe renal impairment; renal route plays minor role
End-stage renal disease (CrCl <15)Avoid use (FDA PI)
Switching from entacapone25 mg once daily at bedtimeIncrease to 50 mg after 1 week if needed50 mg/dayStop entacapone on the same day; start opicapone at bedtime
Based on BIPARK-I switching protocol
Elderly (≥65 years)50 mg once dailyStandard50 mg/day52% of trial patients were ≥65; no dose adjustment needed
Clinical Pearl: Empty Stomach and Bedtime Dosing

Food significantly reduces opicapone absorption (Cmax −62%, AUC −31%, Tmax delayed 4 hours). Bedtime dosing on an empty stomach is recommended, as it separates the dose from meals and provides COMT inhibition throughout the following day’s levodopa doses. Unlike entacapone, there is no need to adjust the dosing frequency — one capsule at bedtime covers all next-day levodopa doses.

Do Not Stop Abruptly

Rapid withdrawal of drugs that increase central dopaminergic tone, including opicapone via its effect on levodopa, can trigger a symptom complex resembling neuroleptic malignant syndrome. When discontinuing, monitor patients and adjust other dopaminergic therapies as needed.

PK

Pharmacology

Mechanism of Action

Opicapone is a selective, reversible, peripherally acting COMT inhibitor that blocks the O-methylation of levodopa to 3-O-methyldopa in peripheral tissues. Its high binding affinity and very slow dissociation from the COMT enzyme result in sustained inhibition that persists well beyond the elimination of the parent compound from plasma. Despite a short plasma half-life of 1–2 hours, the half-life of erythrocyte COMT inhibition is 60–130 hours, reflecting opicapone’s tight enzyme binding rather than circulating drug or metabolite activity. The major circulating metabolite is the pharmacologically inactive 3-O-sulfate (BIA 9-1103, t½ 94–122 hours); a minor reduced metabolite (BIA 9-1079, <10%) has some COMT inhibitory activity in preclinical studies. This unique pharmacodynamic profile enables once-daily bedtime dosing with sustained COMT inhibition across all next-day levodopa doses.

ADME Profile

ParameterValueClinical Implication
AbsorptionTmax ~2 h (range 1–2.5 h); bioavailability ~20%; moderate-fat meal reduces Cmax by 62% and AUC by 31%, delays Tmax by 4 hMust take on empty stomach (1 h before and ≥1 h after food); bedtime dosing facilitates this requirement
DistributionProtein binding >99%; does not cross BBB; peripherally selective; does not affect protein binding of warfarin, digoxin, diazepam, or tolbutamide in vitroVery high protein binding limits tissue distribution; no displacement interactions expected at therapeutic concentrations
MetabolismPrimarily to 3-O-sulfate (BIA 9-1103, 67% of circulating drug, inactive), methylated derivative (21%, inactive), reduced derivative (BIA 9-1079, <10%, active in preclinical studies), and glucuronide (inactive); non-CYP mediated; no CYP inhibition or inductionSulfate metabolite (BIA 9-1103) has t½ 94–122 h but is pharmacologically inactive; sustained >24 h COMT inhibition is due to opicapone’s tight enzyme binding, not circulating metabolite activity; no CYP-based drug interactions
EliminationParent t½ 1–2 h; ~70% recovered in faeces (22% as unchanged drug); renal elimination plays a minor role in clearanceRapid parent elimination but sustained pharmacodynamic effect via long-lived metabolite; hepatic impairment increases exposure (biliary excretion is major route)
SE

Side Effects

Data from pooled BIPARK-I and BIPARK-II pivotal trials (N=750 total; 265 on opicapone 50 mg, 244 on 25 mg, 257 on placebo). Most adverse effects are dopaminergic, resulting from enhanced levodopa exposure. Notably, significant diarrhea and colitis — the key tolerability issues with entacapone — are not characteristic of opicapone.

≥10%Very Common
Adverse EffectIncidenceClinical Note
Dyskinesia18.3% (vs 6.2% placebo; pooled analysis)Most common adverse effect; usually occurs within first 2–3 weeks; after LD dose adjustment, rate decreases to ~8.3% (vs 1.6% placebo); severe in only 1.2%
1–10%Common (≥4% and > Placebo per FDA PI)
Adverse EffectIncidenceClinical Note
Constipation5.7% (vs 1.9% placebo)Unlike entacapone (where diarrhea predominates), constipation is the GI concern with opicapone
Blood creatine kinase increased≥4% > placeboMonitor CPK if muscle symptoms arise; usually asymptomatic elevations
Hypotension / syncope≥4% > placeboDopaminergic mechanism; caution during dose adjustment period; lying/standing BP
Weight decreased≥4% > placeboMonitor body weight; may relate to enhanced dopaminergic tone or reduced appetite
Insomnia5.1% (vs 1.6% placebo)Pooled analysis data; bedtime dosing does not appear to worsen
Dry mouth4.7% (vs 1.2% placebo)May overlap with anticholinergic medications in PD regimen
SeriousSerious (Regardless of Frequency)
Adverse EffectEstimated FrequencyTypical OnsetRequired Action
Hallucinations / psychosisUncommon (<5%)Variable; increased dopaminergic toneConsider stopping opicapone; patients with major psychotic disorders should not ordinarily receive opicapone
Impulse control disordersUncommon (class effect)Weeks to monthsScreen at every visit; consider dose reduction of dopaminergic therapy; involve caregivers
Withdrawal-emergent hyperpyrexia / NMS-like syndromeRare (class effect)During rapid withdrawal of dopaminergic therapyTaper gradually; monitor temperature, CPK, mental status
Syncope≥4% > placeboUsually during dose adjustment periodMonitor BP; adjust concurrent antihypertensives; ensure adequate hydration
DiscontinuationDiscontinuation & Tolerability
Serious Adverse Events (Pooled)
2.0% opicapone vs 4.9% placebo
Serious adverse events were LOWER in opicapone group than placebo in BIPARK pooled analysis
Key Safety Distinction
No severe diarrhea
No severe diarrhea, melanoma, myocardial infarction, or liver dysfunction in opicapone group (pooled)
Managing Dyskinesia

Dyskinesia (18.3%) is the most common adverse effect and typically occurs within the first 2–3 weeks of treatment. In the pivotal trials, after an initial levodopa/carbidopa dose adjustment period, dyskinesia rates decreased substantially (8.3% opicapone vs 1.6% placebo). Most patients can start opicapone without changing their LD/CD regimen, adjusting only if dyskinesia emerges. Severe dyskinesia was uncommon (1.2% vs 0.8% placebo).

Int

Drug Interactions

Opicapone has a cleaner interaction profile than CYP-metabolised drugs. It does not inhibit or induce major CYP enzymes and has no clinically significant PK interactions with warfarin, repaglinide, rasagiline, selegiline, pramipexole, ropinirole, or amantadine (all studied per FDA PI).

MajorNon-Selective MAO Inhibitors (phenelzine, tranylcypromine, isocarboxazid)
MechanismCombined COMT + MAO inhibition prevents two major catecholamine degradation pathways
EffectRisk of hypertensive crisis from catecholamine accumulation
ManagementContraindicated; do not use concomitantly
FDA PI
ModerateCOMT-Metabolised Catecholamines (epinephrine, norepinephrine, dobutamine, isoproterenol)
MechanismCOMT inhibition reduces peripheral metabolism of exogenous catecholamines
EffectPossible arrhythmias, increased HR, excessive BP changes (regardless of route)
ManagementMonitor cardiovascular status closely if catecholamines required
FDA PI
MinorSelective MAO-B Inhibitors (selegiline, rasagiline)
MechanismNo PK interaction demonstrated; selective MAO-B does not affect catecholamine metabolism significantly
EffectSafe to combine; no dose adjustment needed
ManagementRoutine monitoring
FDA PI
MinorLevodopa / Carbidopa
MechanismEnhanced LD bioavailability through sustained COMT inhibition (therapeutic effect)
EffectDyskinesia (18.3% vs 6.2%); enhanced dopaminergic effects
ManagementAdjust LD dose/frequency if dyskinesia occurs; most patients maintained stable LD through 1 year
FDA PI
Mon

Monitoring

  • DyskinesiaClosely for first 2–3 weeks
    Routine
    Most common adverse effect (18.3%); usually resolves with LD dose adjustment. After initial adjustment period, rate drops to ~8.3%.
  • Blood PressureBaseline, each visit
    Routine
    Hypotension/syncope among most common adverse reactions (≥4% > placebo). Lying and standing measurements.
  • NeuropsychiatricEach visit
    Routine
    Screen for hallucinations, psychosis, ICDs (gambling, hypersexuality, spending). Patients with major psychotic disorders should not ordinarily receive opicapone.
  • Body WeightEach visit
    Routine
    Weight decrease among most common adverse reactions per FDA PI.
  • Creatine KinaseIf muscle symptoms arise
    Trigger-Based
    Blood CPK increase reported (≥4% > placebo); usually asymptomatic. Check if myalgia, weakness, or dark urine occur.
  • Hepatic FunctionBaseline (if risk factors)
    Trigger-Based
    No mandatory LFT monitoring required (unlike tolcapone). Check baseline if hepatic disease suspected — moderate impairment requires 25 mg dose; severe is contraindicated.
  • Skin ExaminationAnnually
    Routine
    PD patients have elevated melanoma risk (disease-related). No melanoma cases in opicapone trials.
CI

Contraindications & Cautions

Absolute Contraindications

  • Concomitant non-selective MAO inhibitors (phenelzine, tranylcypromine, isocarboxazid) — risk of hypertensive crisis.
  • Pheochromocytoma, paraganglioma, or other catecholamine-secreting neoplasms — COMT inhibition blocks catecholamine degradation.

Relative Contraindications (Specialist Input Recommended)

  • Major psychotic disorder: Opicapone may exacerbate psychosis via enhanced dopaminergic tone.
  • Severe hepatic impairment (Child-Pugh C): Not studied; avoid use.
  • End-stage renal disease (CrCl <15 mL/min): Avoid use (FDA PI).

Use with Caution

  • Moderate hepatic impairment (Child-Pugh B): AUC increased ~84%; reduce to 25 mg once daily.
  • Severe renal impairment (CrCl 15–29): Monitor for adverse effects; discontinue if tolerability issues arise.
  • History of NMS or non-traumatic rhabdomyolysis: EMA contraindicates; FDA PI advises caution.
FDA Class-Wide Regulatory Warning Falling Asleep During Activities of Daily Living

Patients treated with dopaminergic medications, including opicapone in combination with levodopa, have reported suddenly falling asleep without warning during daily activities including driving. Patients should be advised not to drive or engage in hazardous activities until they have gained sufficient experience with the medication.

Pt

Patient Counselling

Purpose of Therapy

Opicapone helps your levodopa medication work more effectively throughout the day by blocking an enzyme that breaks down levodopa in your body. Unlike some similar medications, you only need to take opicapone once a day at bedtime, and it works continuously to extend the benefit of every levodopa dose you take the next day.

How to Take

Take one capsule at bedtime on an empty stomach. Do not eat for at least 1 hour before and 1 hour after taking the capsule. Food significantly reduces how well the medication is absorbed.

Involuntary Movements (Dyskinesia)
Tell patientThis medication boosts your levodopa, which may initially cause or worsen involuntary movements. This usually settles after your prescriber adjusts your levodopa dose in the first few weeks.
Call prescriberIf involuntary movements are bothersome or increasing.
Empty Stomach Requirement
Tell patientFood reduces the absorption of this medication by about one-third. Taking it at bedtime on an empty stomach is the easiest way to follow this requirement.
Call prescriberIf you are having difficulty maintaining the fasting requirement around dosing times.
Dizziness & Blood Pressure Changes
Tell patientYou may experience dizziness or fainting, especially when standing up. Rise slowly, particularly during the first weeks of treatment.
Call prescriberIf you faint, feel very light-headed, or notice your heart rate is abnormal.
Unusual Urges & Compulsive Behaviours
Tell patientMedications that increase dopamine activity can cause unusual urges such as gambling, increased sexual behaviour, or compulsive shopping. Caregivers should be informed.
Call prescriberIf you or your family notice new or increased gambling, spending, sexual urges, or compulsive eating.
Do Not Stop Suddenly
Tell patientStopping suddenly can cause a dangerous condition with high fever, muscle stiffness, and confusion. Always follow your prescriber’s instructions.
Call prescriberIf you develop fever, severe stiffness, or confusion, especially if any of your Parkinson’s medications have been changed.
Ref

Sources

Regulatory (PI / SmPC)
  1. ONGENTYS (opicapone) Capsules — FDA Prescribing Information. Initial approval 2020; revised 2025. accessdata.fda.govPrimary regulatory source for dosing (50 mg QD at bedtime), hepatic/renal adjustments, adverse reaction data, PK parameters, and contraindications.
  2. ONGENTYS (opicapone) Capsules — FDA Prescribing Information. 2020 original label. accessdata.fda.govOriginal FDA approval label; source for clinical study design (BIPARK-I/II) and PK drug interaction data.
  3. ONGENTYS (opicapone) — DailyMed Label. dailymed.nlm.nih.govCurrent DailyMed listing confirming dosing, contraindications, and adverse reaction profile.
Key Clinical Trials
  1. Ferreira JJ, Lees A, Rocha JF, et al. Opicapone as an adjunct to levodopa in patients with Parkinson’s disease and end-of-dose motor fluctuations: a randomised, double-blind, controlled trial. Lancet Neurol. 2016;15(2):154–165. doi:10.1016/S1474-4422(15)00336-1BIPARK-I pivotal trial: opicapone 50 mg significantly reduced off-time vs placebo; active-controlled arm included entacapone.
  2. Lees AJ, Ferreira J, Rascol O, et al. Opicapone as adjunct to levodopa therapy in patients with Parkinson disease and motor fluctuations: a randomized clinical trial. JAMA Neurol. 2017;74(2):197–206. doi:10.1001/jamaneurol.2016.4703BIPARK-II pivotal trial: confirmed efficacy of opicapone 50 mg in reducing off-time; supported FDA approval.
  3. Lees A, Ferreira JJ, Rocha JF, et al. Safety profile of opicapone in the management of Parkinson’s disease. J Parkinsons Dis. 2019;9(4):733–740. doi:10.3233/JPD-191593Pooled safety analysis of BIPARK-I/II (N=750); source for dyskinesia 18.3% vs 6.2%, constipation 5.7%, insomnia 5.1% figures.
Guidelines
  1. Fox SH, Katzenschlager R, Lim SY, et al. International Parkinson and Movement Disorder Society Evidence-Based Medicine Review: Update on Treatments for the Motor Symptoms of Parkinson’s Disease. Mov Disord. 2018;33(8):1248–1266. doi:10.1002/mds.27372MDS evidence review classifying opicapone as “efficacious” for reducing off-time in motor fluctuations (updated classification).
Mechanistic / Basic Science
  1. Kiss LE, Soares-da-Silva P. Medicinal chemistry of catechol-O-methyltransferase (COMT) inhibitors and their therapeutic utility. J Med Chem. 2014;57(21):8692–8717. doi:10.1021/jm500572bComprehensive review of COMT inhibitor chemistry; describes opicapone’s tight-binding, slow off-rate mechanism and comparison with tolcapone/entacapone.
  2. Bonifacio MJ, Palma PN, Almeida L, Soares-da-Silva P. Catechol-O-methyltransferase and its inhibitors in Parkinson’s disease. CNS Drug Rev. 2007;13(3):352–379. doi:10.1111/j.1527-3458.2007.00020.xOverview of COMT biology and pharmacology; provides context for the development of third-generation COMT inhibitors.
Pharmacokinetics / Special Populations
  1. Opicapone. In: Drugs.com Monograph for Professionals. drugs.com/monographConsolidated professional monograph with PK data, drug interaction summary, and dosing guidance including entacapone switching protocol.
  2. Ferreira JJ, Lees A, Santos A, Hernandez B, Rocha JF, Soares-da-Silva P. Effect of opicapone on levodopa pharmacokinetics in patients with fluctuating Parkinson’s disease. Mov Disord. 2022;37(12):2448–2456. doi:10.1002/mds.29193Phase II PK study demonstrating opicapone 50 mg increases LD bioavailability with avoidance of trough levels even at lower LD doses.
  3. Rocha JF, Almeida L, Falcão A, et al. Opicapone: a short lived and very long acting novel catechol-O-methyltransferase inhibitor following multiple dose administration in healthy subjects. Br J Clin Pharmacol. 2013;76(5):763–775. doi:10.1111/bcp.12081Key Phase I PK study defining the short parent t½ (1–2 h), long sulfate metabolite t½ (94–122 h), and >24 h COMT inhibition duration.
  4. Reichmann H, Gurévich T, Gama H, Soares-da-Silva P. Evaluating opicapone as add-on treatment to levodopa/DDCI in patients with Parkinson’s disease. Degener Neurol Neuromuscul Dis. 2022;12:61–74. PMC9365060Comprehensive review of BIPARK pooled data, COMT inhibition comparisons (opicapone 99% vs entacapone 68%), and long-term safety data.