Unwanted/uncontrolled movements, constipation, drowsiness, dizziness, or weight loss may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Some people taking this medication along with levodopa/carbidopa have fallen asleep suddenly during their usual daily activities (such as talking, eating, driving). In some cases, sleep occurred without any feelings of drowsiness beforehand. This sleep effect may occur anytime during treatment with opicapone and levodopa/carbidopa even if you have used these medications for a long time. If you experience increased sleepiness or fall asleep during the day, do not drive or do other possibly dangerous activities until you have discussed this effect with your doctor. Your risk of this sleep effect is increased by using alcohol or other medications that can make you drowsy. See also Precautions section.
Tell your doctor right away if you have any serious side effects, including: fast/irregular heartbeat, mental/mood changes (such as agitation, confusion, hallucinations), unusual strong urges (such as increased gambling, uncontrolled spending, binge eating, increased sexual urges).
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.