This medication is used to treat movement disorders caused by Parkinson's disease. It does not cure Parkinson's disease, but it may improve shakiness (tremor), muscle stiffness, loss of normal movement as your dose of other Parkinson's medication wears off (end-of-dose failure), and sudden switching between normal movement and stiffness ("on-off" problems). It may improve your range of motion and ability to walk, dress, and exercise. Selegiline is usually used in combination with other medicines (such as levodopa, carbidopa).

Selegiline is an enzyme blocker (MAO inhibitor) that works by slowing the breakdown of certain natural substances in the brain (neurotransmitters such as dopamine, norepinephrine, and serotonin).

Take this medication by mouth as directed by your doctor, usually twice daily with breakfast and lunch. Taking selegiline late in the day may cause trouble sleeping. The dosage is based on your medical condition and response to treatment. Do not increase your dose or take it more often than directed.

After you have been taking selegiline for 2 or 3 days, your doctor may direct you to lower your levodopa dose. Follow your doctor's instructions closely. Do not stop or change the dose of any of your medications without first talking with your doctor.

It may take a few weeks for the full benefits of the drug to be noticed. Do not stop taking this drug without first consulting your doctor. Tell your doctor if the medication stops working well or if your condition gets worse.

Dizziness, abdominal pain, dry mouth, nausea, stomach upset, trouble sleeping, and headache 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.

If you are also taking levodopa, you may experience more side effects from the levodopa when taking selegiline. Tell your doctor right away if any of these side effects occur: nausea, shakiness, muscle stiffness, mental/mood changes such as hallucinations/abnormal dreams. Your doctor may need to change your medication or dose. Do not stop or change the dose of your levodopa without talking with your doctor first.

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 selegiline 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 selegiline 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. See also Precautions section.

Tell your doctor right away if you have any serious side effects, including:

• fainting
• loss of balance
• mental/mood changes (such as agitation, confusion, depression, hallucinations)
• unusual strong urges (such as increased gambling, increased sexual urges)
• worsening muscle stiffness/twitching
• changes in sexual ability/interest
• increased shaking (tremor)
• swollen ankles/legs
• difficulty urinating
• unusual weight gain
• easy bleeding/bruising
• black/tarry stools
• vomit that looks like coffee grounds

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 also Drug Interactions section.) Get medical help right away if any of these serious side effects occur:

• frequent/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)

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome. 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:

• hallucinations
• unusual restlessness
• loss of coordination
• fast heartbeat
• severe dizziness
• unexplained fever
• severe nausea/vomiting/diarrhea
• twitching muscle

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)
• 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.

Before taking selegiline, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• a certain adrenal gland tumor (pheochromocytoma)
• cerebrovascular disease (such as stroke)
• heart problems (such as heart failure, heart attack)
• bleeding problems
• history of severe/frequent headaches
• peptic ulcer
• diabetes
• personal/family history of mental/mood disorders (such as schizophrenia, bipolar disorder)
• personal/family history of high blood pressure
• liver disease
• overactive thyroid (hyperthyroidism)

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). See also Side Effects section.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). You may need to stop taking selegiline before surgery. Follow your doctor's instructions carefully.

During pregnancy, selegiline should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this drug and for 7 days after the last dose. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with selegiline include:

• antidepressants (including bupropion, maprotiline, mirtazapine)
• other MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, tranylcypromine)
• appetite suppressants (such as diethylpropion)
• drugs for attention deficit disorder (such as atomoxetine, methylphenidate)
• apraclonidine
• buspirone
• carbamazepine/oxcarbazepine
• cyclobenzaprine
• deutetrabenazine
• certain herbal products (such as ephedra/ma huang)
• cold medications/nasal decongestants (such as phenylephrine, phenylpropanolamine, pseudoephedrine)
• fentanyl
• metoclopramide
• street drugs (such as LSD, mescaline)
• stimulants (such as amphetamines, ephedrine)
• 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, dextromethorphan, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine, TCAs such as amitriptyline/doxepin), certain opioid medications (such as meperidine, methadone, pentazocine, propoxyphene, tramadol, tapentadol), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

Tell your doctor or pharmacist if you are using any of these medications before, during, or within 2 weeks after treatment with selegiline. Tell your doctor or pharmacist if you have taken fluoxetine during at least 5 weeks before starting selegiline. Discuss with your doctor how much time to wait between starting or stopping any of these drugs and taking selegiline.

Check the labels on all your medicines (such as allergy, cough-and-cold products, diet pills) because they may contain dextromethorphan, decongestants, or stimulants. Ask your pharmacist about the safe use of those products.

To prevent a very serious high blood pressure reaction, it is very important that you follow a special diet recommended by your doctor or dietician in order to limit your intake of tyramine while you are taking this medicine. Avoid foods and beverages that are high in tyramine, including: aged cheeses (such as bleu, cheddar, parmesan), dried/aged/fermented meats and sausages (such as salami, liverwurst), preserved fish (such as pickled herring), products containing large amounts of yeast (such as concentrated yeast extract, bouillon cubes, powdered soup/gravy, homemade or sourdough bread), fermented foods (such as sauerkraut, kim chee), most soybean products (such as soy sauce, tofu), broad/fava beans, red wine, sherry, tap beers, vermouth. Limit or avoid foods that are moderate in tyramine, including: avocados, bananas, eggplant, green beans, raisins, raspberries, red plums, spinach, tomatoes, chocolate, cultured dairy products (such as buttermilk, yogurt, sour cream), fish eggs, pate, peanuts, coffee, cola, alcohol-free beer, bottled beer, distilled spirits, port, white wine. Consult your doctor or dietician for more details and a complete list of other tyramine-containing foods you should limit or avoid. Get medical help right away if you notice symptoms of very high blood pressure such as unusually fast/slow heartbeat, vomiting, unexplained sweating, headache, chest pain, sudden vision changes, weakness on one side of the body, trouble speaking.

This medication may interfere with certain medical/lab tests (such as brain scan for Parkinson's disease), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may be not appear for up to 12 hours and may include excitement, irritability, restlessness, weakness, drowsiness, flushing, sweating, fast heartbeat, headache, confusion, and seizures.

Do not share this medication with others.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.