Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Onstryv (Safinamide). If you are concerned about side effects, discuss the risks and benefits of Onstryv (Safinamide) with your doctor.

The following side effects have been reported by at least 1% of people taking Onstryv (Safinamide). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• balance problems
• bloating
• decreased sensitivity to touch
• dizziness or lightheadedness when rising from a sitting or lying position
• falls
• feeling anxious
• headache
• heartburn
• nausea
• prolonged muscle contraction
• sensation of spinning
• stomach discomfort
• tingling and numbness
• trouble sleeping
• vomiting
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• behaviour changes (e.g., delusions, aggression, compulsive spending, eating, gambling, sexual behaviour)
• chest pain
• clouding vision
• difficulty performing intentional movement
• Fever
• hallucinations (hearing or seeing things that aren't there)
• high blood pressure
• increased frequency of infections
• muscle stiffness
• skin lesions (new or changing)
• suddenly falling asleep without warning
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)
• uncontrolled movement

Stop taking the medication and seek immediate medical attention if any of the following occur:

• loss of vision or blind spot in normal vision
• signs of a Heart Attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)
• signs of a hypertensive reaction (e.g., severe headache with confusion and blurred vision, nausea, vomiting, severe anxiety, difficulty breathing, severe chest pain, seizures)
• signs of neuroleptic malignant syndrome (e.g., agitation; anxiety; confusion; fast, irregular, or pounding heartbeat; increased body temperature; muscle rigidity)
• symptoms of serotonin syndrome (e.g., confusion, fast heartbeat, hallucinations, restlessness, shaking, shivering, sudden jerking of muscles, sweating)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Onstryv (Safinamide).

50 mg
Each orange-to-copper, round, biconcave, immediate release, film-coated tablet with metallic gloss, and embossed with "50" on one side of the tablet, contains Onstryv (Safinamide) mesylate equivalent to 50 mg of Onstryv (Safinamide). Nonmedicinal ingredients: crospovidone type A, magnesium stearate, microcrystalline cellulose, silica, and colloidal anhydrous; film-coating: hypromellose, iron oxide red (C.I. No. 77491), mica (C.I. No. 77019), polyethylene glycol 6000, and titanium dioxide (C.I. No. 77891).

100 mg
Each orange-to-copper, round, biconcave, immediate release, film-coated tablet with metallic gloss, and embossed with "100" on one side of the tablet, contains Onstryv (Safinamide) mesylate equivalent to 100 mg of Onstryv (Safinamide). Nonmedicinal ingredients: crospovidone type A, magnesium stearate, microcrystalline cellulose, silica, and colloidal anhydrous; film-coating:  hypromellose, iron oxide red (C.I. No. 77491), mica (C.I. No. 77019), polyethylene glycol 6000, and titanium dioxide (C.I. No. 77891).

Do not take Onstryv (Safinamide) if you:

• are allergic to Onstryv (Safinamide) or any ingredients of the medication
• are taking Dextromethorphan
• have severe liver impairment
• have any eye conditions that affect the Retin A of the eye (e.g., uveitis, retinal degeneration, albinism, inherited retinopathy, severe diabetic retinopathy)
• are taking or have taken a non-selective monoamine oxidase inhibitor (MAOI) within the last 2 weeks (e.g., Moclobemide, Phenelzine, Tranylcypromine)
• are taking any of the following medications or have taken any of the following medications within the past 2 weeks
• Cyclobenzaprine
• Linezolid
• methylene blue (a dye used in diagnostic tests)
• opioid medications (e.g., Meperidine, Methadone, propoxyphene, Tramadol, Tapentadol)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., Desvenlafaxine, Duloxetine, Venlafaxine)
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• St. John's wort

There may be an interaction between Onstryv (Safinamide) and any of the following:

• alcohol
• alpha-agonists (e.g., Clonidine, methyldopa)
• alpha/beta-agonists (e.g., Epinephrine, norepinephrine)
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• anti-emetics (e.g., Granisetron, Ondansetron)
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• apraclonidine
• Atomoxetine
• atropine (for eyes)
• Betahistine
• Bezafibrate
• brimonidine
• Bromocriptine
• fast acting bronchodilators (e.g., salbutamol, terbutaline)
• long acting bronchodilators (e.g., formoterol, salmeterol)
• Buprenorphine
• Buspirone
• Cabergoline
• caffeine
• Carbamazepine
• cyclobenzaprine
• cyproheptadine
• decongestant cold medications (e.g., phenylephrine, Pseudoephedrine)
• decongestant eye drops and nose sprays (e.g., naphazoline, oxymetazoline, xylometazoline)
• dexmethylphenidate
• dextromethorphan
• Diabetes medications (e.g., chlorpropamide, Dapagliflozin, Glyburide, insulin, Metformin, Rosiglitazone)
• dipivefrin
• Disopyramide
• Domperidone
• dopamine
• diphenoxylate
• Entacapone
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• guanethidine
• isoniazid
• levodopa
• linezolid
• lithium
• methadone
• methylene blue
• Methylphenidate
• Metoclopramide
• Midodrine
• Mirtazapine
• monoamine oxidase inhibitors (M.O.S. e.g., Maprotiline, moclobemide, Rasagiline, Selegiline, tranylcypromine)
• narcotic pain relievers (e.g., Codeine, Fentanyl, Morphine, Oxycodone)
• Pindolol
• St. John's wort
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
• tapentadol
• Tetrabenazine
• theophyllines (e.g., Aminophylline, Oxtriphylline, Theophylline)
• tolcapone
• tramadol
• Trazodone
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• "triptan" migraine medications (e.g., Eletriptan, Rizatriptan, Sumatriptan)
• Tryptophan

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Onstryv (Safinamide). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Onstryv (Safinamide).

Abnormal heart rhythms: Onstryv (Safinamide) can cause abnormal heart rhythms. Certain medications may increase this risk. If you have an irregular heartbeat or are taking other medications that affect the heartbeat, discuss with your doctor how Onstryv (Safinamide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Onstryv (Safinamide), and whether any special monitoring is needed.

Antidepressant medication: Severe reactions are possible when Onstryv (Safinamide) is combined with medications and natural products used to treat Depression. Avoid combining Onstryv (Safinamide) and antidepressants. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. Coma and death are also possible.

If you have taken antidepressants recently, discuss with your doctor how Onstryv (Safinamide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Onstryv (Safinamide), and whether any special monitoring is needed.

Blood pressure: Onstryv (Safinamide) may cause increased blood pressure. If you have high blood pressure or take medications to control blood pressure, discuss with your doctor how Onstryv (Safinamide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Onstryv (Safinamide), and whether any special monitoring is needed.

Impulse control: People taking Onstryv (Safinamide) have experienced abnormal behaviour such as compulsive gambling, compulsive shopping, hypersexuality, and binge eating. If you experience these symptoms or any other behaviour change while taking Onstryv (Safinamide), contact your doctor immediately.

Liver function impairment: Liver disease or reduced liver function may cause Onstryv (Safinamide) to build up in the body, causing side effects. If you have reduced liver function or liver disease, discuss with your doctor how Onstryv (Safinamide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Onstryv (Safinamide), and whether any special monitoring is needed. Do not take Onstryv (Safinamide) if you have moderate or severe liver function impairment.

Melanoma: People with Parkinson's disease may be at increased risk of developing melanoma (a type of Skin Cancer). It is not known if this increased risk is due to Parkinson's disease or to the medications used to treat Parkinson's disease. You and your doctor should check your skin regularly for signs of skin cancer (e.g., moles that have an irregular shape or border, moles that change colour, or moles that are larger than 6 mm). Talk to your doctor if you have any concerns.

Mental health: Medications that affect dopamine may make behavior and thought disturbances worse for people who have psychotic conditions. Rarely, they may also cause symptoms of psychosis and mania to develop in people who have not had these symptoms before. If you experience symptoms such as hallucinations, mania (feeling unusually over-excited or uninhibited), or delusional thinking, or notice them in a family member who is taking Onstryv (Safinamide), contact your doctor as soon as possible.

Neuroleptic malignant syndrome (NMS): Rarely, Onstryv (Safinamide) can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting, get immediate medical attention.

Sudden onset of sleep: As with other medication to treat Parkinson's disease, Onstryv (Safinamide) can cause the sudden, unpredictable onset of sleep. This can happen while participating in the daily activities of living, including driving or operating machinery. This effect may occur at any point while taking the medication.  You should use caution if driving or operating machinery while taking Onstryv (Safinamide).  If you experience drowsiness or sudden onset of sleep, do not drive or operate machinery, and contact your doctor as soon as possible.

Uncontrolled movements: Onstryv (Safinamide) may cause an increase in irregular, jerky movements or uncontrolled body movements when it is taken with levodopa. If you notice movement problems worsening, contact your doctor as soon as possible.

Vision problems: Onstryv (Safinamide) may have an effect on the retina of the eye, particularly for people who already have certain vision problems. If you notice any changes to your vision, contact your doctor as soon as possible. People with eye problems involving the retina should not use Onstryv (Safinamide).

Pregnancy: Onstryv (Safinamide) should not be used during pregnancy. If you become pregnant while taking Onstryv (Safinamide), contact your doctor immediately.

Breast-feeding: It is not known if Onstryv (Safinamide) passes into breast milk. If you are a breast-feeding mother and are taking Onstryv (Safinamide), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Onstryv (Safinamide) have not been established for children.