Rasagiline: what it treats, how to take it, side effects
Last updated September 3, 2026.
Rasagiline is an MAO-B inhibitor - it raises the amounts of certain natural substances in the brain, including the dopamine Parkinson's runs low on. You may know it as Azilect. Used alone or with other Parkinson's medications - and it comes with a food list and a medication list worth learning.
What does it treat?
The symptoms of Parkinson's disease - tremor at rest, slowed movement, stiffness, stooped posture, shuffling walk.
How do you take it?
Exactly as directed, same time daily, with or without food. Two restriction lists come with it. Foods very high in tyramine are out - aged cheeses like Stilton or blue cheese are the classic example; your doctor or dietitian owns the full list, and feeling unwell after certain foods is a call. Medications: St. John's wort and dextromethorphan - the cough medicine - interact, and many antidepressants and cold products need the green light first; never start anything new without the pharmacist checking it against this one. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: mild headache, joint or neck pain, heartburn, nausea, vomiting, stomach pain, constipation, diarrhea, loss of appetite, weight loss, flu-like symptoms, fever, sweating, and red, swollen, or itchy eyes.
- Serious - call your doctor immediately: severe headache; blurred vision; seizures; chest pain; shortness of breath or difficulty breathing; confusion; unconsciousness; slow or difficult speech; dizziness or faintness; and weakness or numbness of an arm or leg.
Who should not take it?
The interaction list decides much of it: certain antidepressants, St. John's wort, dextromethorphan, and other MAO inhibitors are incompatible. Flag liver disease, high blood pressure, and mental illness history. If you become pregnant, call your doctor.
When is it an emergency?
A sudden severe headache with confusion or chest pain - the pressure-reaction pattern - a seizure, or fainting is a 911 call. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why can't I eat aged cheese?
Tyramine: aged, cured, and fermented foods carry it - and MAO inhibitors block the enzyme that clears it, so the level can spike blood pressure dangerously. Aged cheeses like Stilton or blue are the classic example; the full list comes from your doctor or dietitian. The reaction pattern is worth knowing cold: sudden severe headache, confusion, chest pain, pounding heartbeat - that is an emergency, not indigestion.
Why does the pharmacist need to check cold medicine?
Dextromethorphan - the cough suppressant in most cold remedies - interacts with rasagiline, and St. John's wort does too. Many antidepressants and other MAO inhibitors are incompatible outright. The habit that makes this safe: every new product - prescription, OTC, herbal, supplement - gets checked against this one before the first dose. One question, every time, no exceptions.
How is this different from levodopa?
Different lane, same city: levodopa supplies dopamine; rasagiline slows its breakdown, raising what is already there. Alone early on, or added to levodopa later as the disease asks more - your doctor sequences the combination. Many regimens end up layered; each layer has its own rules, and this one's are the food and interaction lists.
What is the severe-headache warning about?
The pressure reaction: a sudden severe headache - with blurred vision, chest pain, confusion, or pounding heartbeat - can signal a dangerous blood-pressure spike, usually from a tyramine or interaction slip. That combination is a 911 call, not a lie-down. It is rare when the lists are followed - which is why the lists are followed.
Will it affect my blood pressure or mood?
Both sit on the watch list: dizziness or faintness - the pressure side - and confusion or mood changes are call-your-doctor items, and blood pressure history shapes the monitoring. The common effects are the milder set - headache, heartburn, flu-like feelings, joint pain - usually tolerable and worth a mention only if they persist.
What happens if I miss a dose of rasagiline?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. Once-daily dosing forgives a late morning. The anchor - with breakfast, with the first coffee - keeps the question rare. Missed several days? Mention it at the next visit rather than improvising.