Ongentys Side Effects: What to Expect and When to Call Your Doctor

What You Should Know About Ongentys Side Effects

Starting a new medication always comes with questions — especially about side effects. If you've been prescribed Ongentys (Opicapone) for Parkinson's disease off episodes, understanding what to expect can help you feel more prepared and know when something needs medical attention.

Ongentys is generally well-tolerated, but like all medications, it can cause side effects. Some are common and manageable, while others are rare but serious. This guide covers both, straight from the FDA labeling, so you know exactly what to watch for.

What Is Ongentys?

Ongentys is a COMT inhibitor made by Neurocrine Biosciences. It's taken as a 50 mg capsule once daily at bedtime alongside Levodopa/Carbidopa to reduce off episodes in people with Parkinson's disease. By blocking the enzyme that breaks down Levodopa, Ongentys helps your Parkinson's medication work longer and more consistently. For a deeper dive, see our guide on what Ongentys is and how it's used.

Common Side Effects

These side effects were reported in clinical trials and are generally mild to moderate. Many improve over time as your body adjusts:

• Dyskinesia (involuntary movements) — This is the most commonly reported side effect. Because Ongentys makes Levodopa last longer, you may experience increased involuntary movements. Your doctor may lower your Levodopa dose to manage this.
• Constipation — A frequent complaint. Staying hydrated, eating fiber-rich foods, and staying active can help.
• Blood creatine kinase increased — Detected through blood tests. Usually not noticeable but your doctor may monitor this.
• Dizziness — Especially when standing up quickly. Take your time when getting out of bed or chairs.
• Headache — Usually mild and tends to improve over time.
• Sleepiness or drowsiness — Be cautious with driving or operating machinery until you know how Ongentys affects you.
• Difficulty sleeping (insomnia) — Despite taking it at bedtime, some people experience trouble falling or staying asleep.
• Abnormal dreams — Some patients report vivid or unusual dreams.
• Dry mouth — Sipping water throughout the day can help.
• Vomiting — Usually mild and temporary.
• Weight decreased — Some patients notice gradual weight loss.
• Low blood pressure (hypotension) — May cause lightheadedness, especially when standing.

Serious Side Effects

While rare, these side effects require immediate medical attention:

Falling Asleep During Daily Activities

Some patients taking Ongentys with Levodopa have fallen asleep while driving, eating, or having a conversation — sometimes without feeling drowsy beforehand. Stop driving and contact your doctor immediately if you experience sudden sleepiness or fall asleep during normal activities.

Hallucinations and Psychotic-Like Behavior

Ongentys can cause or worsen hallucinations (seeing or hearing things that aren't there) and other psychotic behavior. This risk is higher in older adults. Tell your doctor right away if you or your caregiver notices:

• Seeing or hearing things that aren't real
• Confusion or disorientation
• Paranoia or agitation

Impulse Control Disorders

Some people develop strong, hard-to-control urges while taking dopaminergic medications including Ongentys. These can include:

• Compulsive gambling
• Compulsive spending or shopping
• Binge eating
• Unusual sexual urges

These behaviors may not feel abnormal to the person experiencing them, so caregivers should be alert. Contact your doctor if you notice any new compulsive behaviors.

Severe Dyskinesia

While mild dyskinesia is a common side effect, severe involuntary movements can interfere with daily life. If dyskinesia becomes unmanageable, your doctor will likely reduce your Levodopa dose rather than stopping Ongentys.

Severe Low Blood Pressure (Hypotension/Syncope)

Ongentys can cause significant drops in blood pressure, leading to fainting (syncope). This is especially concerning for older adults who are at higher risk for falls. Seek medical attention if you faint or feel extremely lightheaded.

Withdrawal Symptoms

Never stop Ongentys suddenly without your doctor's guidance. Abruptly stopping can cause withdrawal-emergent hyperpyrexia and confusion — a potentially dangerous condition with high fever and altered mental state. Always taper off under medical supervision.

Special Populations

Older Adults (65+)

No dose adjustment is needed for patients 65 and older, but older adults may be more sensitive to side effects like low blood pressure, hallucinations, and falls. Close monitoring is recommended.

Liver Problems

Ongentys is not recommended for patients with moderate or severe liver impairment. If you have liver disease, make sure your doctor knows before starting Ongentys.

Kidney Problems

No dose adjustment is needed for patients with kidney impairment.

Pregnancy and Breastfeeding

Ongentys has not been studied in pregnant or breastfeeding women. Talk to your doctor about the risks and benefits if you are pregnant, planning to become pregnant, or breastfeeding.

How to Manage Side Effects

Here are practical tips for dealing with the most common Ongentys side effects:

1. For dyskinesia: Track when involuntary movements happen and how severe they are. Your doctor can adjust your Levodopa dose — this usually helps significantly.
2. For constipation: Drink plenty of water, eat high-fiber foods, and stay physically active. Over-the-counter stool softeners can help if diet changes aren't enough.
3. For dizziness and low blood pressure: Stand up slowly, especially in the morning. Stay hydrated. Avoid alcohol, which can worsen low blood pressure.
4. For drowsiness: Avoid driving or operating heavy machinery until you know how the medication affects you. Take Ongentys at bedtime as directed.
5. For insomnia: Practice good sleep hygiene — keep a regular bedtime, limit screen time, and keep your bedroom cool and dark.
6. Keep a side effect diary: Note what you experience, when it happens, and how severe it is. This information helps your doctor make the best adjustments.

Remember: most side effects are manageable, and your doctor has tools to help — often by simply adjusting your Levodopa dose. Don't suffer in silence or stop your medication without talking to your doctor first.

Final Thoughts

Ongentys can be an effective way to reduce Parkinson's off episodes, and most people tolerate it well. The key is knowing what to watch for and staying in close communication with your doctor, especially during the first few weeks. If side effects are making it hard to continue treatment, your doctor may adjust your Levodopa dose or explore alternative treatments. For help finding Ongentys at an affordable price, visit Medfinder.