What to Know About Ongentys (Opicapone)

Parkinson's Disease Add-on Drug to Levodopa for Reducing Off Times

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Ongentys (opicapone) is an oral medication taken as an add-on drug to levodopa in people with Parkinson's disease who experience "off" episodes. "Off" episodes are periods of time when a patient's symptoms, like tremor or rigidity, return before the next scheduled dose of levodopa is due.

As a catechol-O-methyltransferase (COMT) inhibitor, Ongentys works by blocking the breakdown of levodopa in the bloodstream. Therefore, more levodopa is available to enter the brain.

In the brain, levodopa is converted into dopamine (the chemical messenger that becomes depleted in Parkinson's disease). With more dopamine in the brain, people with Parkinson's disease undergo an improved control of symptoms.

Levodopa is the "gold standard" or most effective medication for treating the symptoms of Parkinson's disease.

Ongentys May Help Reduce "Off" Times From Levodopa

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Ongentys may be prescribed in patients with Parkinson's disease whose levodopa effect wears off before the next dose is due. Since these "off" episodes occur more commonly in patients who have taken levodopa for a long time (usually five to ten years or more), Ongentys is generally prescribed in patients with advanced Parkinson's disease.

Before Taking

Before prescribing Ongentys, your healthcare provider will consider non-pharmacological strategies for managing your "off" episodes.

For instance, your healthcare provider will want to ensure that your "off" episodes are not due to taking your levodopa dose too late or taking levodopa with meals. Foods, especially those that are high in protein, can impair the absorption of levodopa in your gut.

Additionally, before prescribing Ongentys, your healthcare provider may first change your levodopa regimen—perhaps asking you to take smaller doses more frequently throughout the day.

It's important to tell your healthcare provider about all of your medical conditions, as well as medications, supplements, and vitamins that you take. Some medical conditions or medications may contraindicate use or prompt careful consideration as to whether the pros of treatment with Ongentys outweigh the cons.

Precautions and Contraindications

Ongentys is contraindicated in the following patients:

  • Patients who are currently taking a non-selective monoamine oxidase (MAO) inhibitor, such as Nardil (phenelzine), Parnate (tranylcypromine), and Marplan (isocarboxazid).
  • Patients who have a history of pheochromocytoma, paraganglioma, or another catecholamine-secreting tumor.

Ongentys should also be avoided by patients with the following conditions:

Precaution should be taken in patients with the following conditions:

  • Patients with a sleep disorder or patients taking any medication(s) that makes them sleepy.
  • Patients with intense or unusual urges or behaviors (e.g., compulsive gambling or binge eating).
  • Patients with a history of dyskinesia (sudden, uncontrollable movements)

If you are pregnant or considering pregnancy, be sure to talk with your healthcare provider before taking Ongentys. Human data on the risks associated with taking Ongentys in pregnancy is lacking, but animal studies suggest potential fetal harm. Also, talk with your healthcare provider if you are breastfeeding or considering it. It's unknown if Ongentys passes into breast milk.

Other COMT Inhibitors

Besides Ongentys, other COMT inhibitors that may be prescribed to reduce a patient's "off" episodes include:

  • Comtan (entacapone)
  • Tasmar (Tolcapone)—rarely prescribed due to risk of severe liver injury


Ongentys is available in both 25 and 50 milligram (mg) capsules. The usual dosage is 50 mg taken by mouth once daily at bedtime.


For patients with moderate liver impairment, the recommended dosage is 25 mg. There is no dose adjustment recommended for older individuals.

The above dosages are according to the drug manufacturer. Be sure to check your prescription and talk to your healthcare provider to make sure you are taking the right dose for you.

How to Take and Store

Patients are advised to not eat for one hour before taking Ongentys and for at least one hour after taking it. If a dose is missed, patients should take the next dose at the scheduled time the next day.

If Ongentys is being discontinued, your levodopa dose may need to be adjusted. If you overdose on Ongentys, call your healthcare provider or the poison control center right away or go to the nearest emergency room. You may require medical care in a hospital, along with the removal of the Ongentys through gastric lavage or the administration of activated charcoal.

Patients should store their Ongentys capsules at a temperature below 86 F and keep the drug out of reach from children.

Side Effects

The most common side effects associated with taking Ongentys include:

  • Dyskinesia
  • Constipation
  • Increase in blood creatinine kinase level
  • Low blood pressure
  • A decrease in weight

Less common side effects include:

  • Dry mouth
  • Insomnia
  • High blood pressure

Warnings and Interactions

Ongentys is considered an overall safe and well-tolerated drug. There are, however, several warnings to be cognizant of if you are prescribed this medication.


Patients may develop drowsiness and/or fall asleep during the day while taking Ongentys. If this adverse effect occurs, Ongentys may need to be discontinued. If it's decided to continue Ongentys despite this reaction, patients should be instructed not to drive and to avoid other potentially hazardous activities.

Low Blood Pressure and Fainting

Patients may develop low blood pressure, fainting, or the sensation of fainting when taking Ongentys. If these reactions occur, Ongentys may need to be stopped or alternatively, the dose of other blood-pressure-lowering medications adjusted (if the patient is taking any).


Ongentys may cause new-onset dyskinesia, or it may worsen pre-existing dyskinesia. This reaction may be managed by having your healthcare provider lower the dosage of your levodopa or other dopaminergic drugs.

Hallucinations and Psychosis

Hallucinations and psychotic-like behavior, such as delusions or agitation, may occur in patients on Ongentys. Discontinuation of Ongentys may be considered if one or more of these symptoms is present.

Impulse Control Problems

Patients may engage in various intense, uncontrollable behaviors and urges like binge eating or gambling. Patients may not always recognize these urges as abnormal, so careful monitoring is required by the patient's loved ones and healthcare provider. Ongentys may need to be stopped if these behaviors develop.

Withdrawal Symptoms

When discontinuing Ongentys, patients need to be monitored for symptoms that resemble those seen in neuroleptic malignant syndrome, including fever, confusion, and muscle rigidity. In addition, the patient's other Parkinson's drugs may need to be adjusted during this time.

Cardiovascular Effects

Patients taking Ongentys and another medication metabolized by the COMT enzyme may experience various heart-related effects, including an increase in heart rate, a change in heart rhythm, or a change in blood pressure. Healthcare providers should monitor for these changes.

Examples of medications metabolized by the COMT enzyme include:

  • Isuprel (isoproterenol)
  • EpiPen or Auvi-Q (epinephrine)
  • Levophed (norepinephrine)
  • Intropin (dopamine)
  • Dobutrex (dobutamine)
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Food and Drug Administration. Drug trials snapshots: Ongentys.

  2. Neurocrine Biosciences, Inc. Ongentys [package insert].

  3. Wang L. Protein-restricted diets for ameliorating motor fluctuations in Parkinson's disease. Front Aging Neurosci. 2017;9:206. doi:10.3389/fnagi.2017.00206

  4. Liang T-W, Tarsy D. Medical management of motor fluctuations and dyskinesia in Parkinson disease. Hurtig HI, ed. UpToDate. Waltham, MA: UpToDate.

  5. Watkins P. COMT inhibitors and liver toxicity. Neurology. 2000;55(11 Suppl 4):S51-2; discussion S53-6.

By Colleen Doherty, MD
 Colleen Doherty, MD, is a board-certified internist living with multiple sclerosis.