Dizziness, drowsiness, joint pain, heartburn, nausea, dry mouth, weight loss, or stomach/abdominal pain 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, especially when you first start taking rasagiline. 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. Tell your doctor right away if you have any serious side effects, including: fainting, loss of balance, mental/mood changes (such as confusion, depression, hallucinations), worsening muscle stiffness/twitching/uncontrollable movements, swollen ankles/legs, easy bleeding/bruising, unusual strong urges (such as increased gambling, increased sexual urges). Some people taking rasagiline have fallen asleep suddenly during their usual daily activities (such as talking on the phone, driving). In some cases, sleep occurred without any feelings of drowsiness beforehand. This sleep effect may occur anytime during treatment with rasagiline even if you have used this medication for a long time. If you experience increased sleepiness or fall asleep during the day, do not drive or take part in 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. This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take. Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness. This drug may rarely cause an attack of extremely high blood pressure (hypertensive crisis), which may be fatal. Many drug and food interactions can increase this risk (see How to Use and Drug Interactions sections). Get medical help right away if any of these serious side effects occur: severe headache, fast/slow/irregular/pounding heartbeat, chest pain, neck stiffness/soreness, severe nausea/vomiting, sweating/clammy skin (sometimes with fever), widened pupils, vision changes (such as double/blurred vision), sudden sensitivity to light (photophobia). 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 www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Some products that may interact with this drug include: diet pills/appetite suppressants (such as diethylpropion), drugs for attention deficit disorder (such as atomoxetine, methylphenidate), apraclonidine, bupropion, buspirone, carbamazepine, cyclobenzaprine, deutetrabenazine, dextromethorphan, methyldopa, metoclopramide, certain supplements (such as tryptophan, tyramine), tetrabenazine, certain "triptans" used to treat migraine headaches (such as rizatriptan, sumatriptan, zolmitriptan), valbenazine. The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, tramadol, certain opioid medications (such as fentanyl, meperidine, methadone, tapentadol), certain antidepressants (including maprotiline, mirtazapine, SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine, tricyclics such as amitriptyline/doxepin), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs. Some products can interact with rasagiline if you take them together, or even if you take them weeks before or after taking rasagiline. Tell your doctor or pharmacist if you take anything in the list of products that may interact with this drug, or any of the products that increase serotonin, within 2 weeks before or after taking rasagiline. Also tell them if you have taken fluoxetine within 5 weeks before starting rasagiline. Ask your doctor how much time to wait between starting or stopping any of these drugs and starting rasagiline. Taking other MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Do not take any other MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication. Before using rasagiline, report the use of drugs that may increase the risk of extremely high blood pressure (hypertensive crisis) when combined with rasagiline, including herbal products (such as ephedra/ma Huang), allergy and cough-and-cold products (including dextromethorphan, decongestants such as phenylephrine/pseudoephedrine), and stimulants (such as amphetamines, ephedrine, epinephrine, phenylalanine). Rasagiline should not be used with any of these medications. Talk to your doctor or pharmacist for more details. Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants (such as carisoprodol), and opioid pain relievers (such as codeine, hydrocodone).