Commonly reported side effects of sumatriptan include: dizziness, injection site reaction, vertigo, nausea and vomiting, flushing sensation, tingling sensation, and unpleasant taste. Other side effects include: asthenia, burning sensation, chest discomfort, neck pain, neck stiffness, numbness, throat irritation, feeling of heaviness, flushing, sensation of pressure, and sensation of tightness. See below for a comprehensive list of adverse effects.

Applies to sumatriptan: oral tablet

Other dosage forms:

• nasal powder, nasal spray
• subcutaneous kit, subcutaneous solution
• transdermal patch device assisted

Along with its needed effects, sumatriptan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking sumatriptan:

Less common

• Abdominal or stomach pain
• anxiety
• blurred vision
• changes in patterns and rhythms of speech
• chest pain or tightness
• chills
• confusion
• dizziness
• fast, slow, irregular, pounding, or racing heartbeat or pulse
• headache
• muscle cramps and stiffness
• neck, throat, or jaw pain
• nightmares
• shivering
• sweating
• swelling of the fingers, hands, feet, or lower legs
• tightness in the chest
• trouble breathing

Rare

• Blindness
• chest pain or discomfort
• chest tightness or heaviness
• flushing or redness of the skin, especially on the face and neck
• increased blinking or spasms of the eyelid
• itching, pain, redness, or swelling
• lightheadedness, dizziness, or fainting
• nerve pain
• severe numbness, especially on one side of the face or body
• severe or continuing stomach pain
• trouble speaking or swallowing
• twitching
• unusual bleeding or bruising
• vomiting of blood or material that looks like coffee grounds
• weakness of the arms and legs

Incidence not known

• Agitation
• back, leg, or stomach pains
• bleeding gums
• changes in vision
• muscle twitching
• pinpoint red spots on the skin
• poor coordination
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• restlessness
• skin rash, hives, or itching
• unexplained bleeding or bruising
• unusually warm skin
• weakness in the arm or leg on one side of the body, sudden and severe

Some side effects of sumatriptan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in color vision
• change in hearing
• difficulty with concentrating
• drowsiness
• heartburn
• increased sensitivity of the eyes to sunlight
• joint pain
• muscle aching or cramping
• muscle stiffness or tightness
• swollen joints
• trouble sleeping

Rare

• Aggressiveness
• belching
• change in taste
• feeling halos around lights
• increased sensitivity to pain
• loss of appetite
• numbness, pain, tingling, or weakness
• stomach discomfort or upset
• tingling in the hands and feet
• tunnel vision
• weakness

Applies to sumatriptan: nasal capsule, nasal spray, oral tablet, subcutaneous kit, subcutaneous solution, transdermal film extended release

The more commonly observed adverse reactions have included those of pressure sensation, flushing, tingling, dizziness/vertigo, warm/hot sensation, burning sensation, flushing, and numbness; formulation specific events including injection site reactions, application site pain, and nasal discomfort have been reported.

Life-threatening disturbances of cardiac rhythm, such as ventricular tachycardia and ventricular fibrillation leading to death, and rare reports of acute myocardial infarction, have been reported within a few hours after administration of 5-HT1 agonists.

Chest discomfort is usually noncardiac in origin. A survey of 453 migraine patients found chest symptoms occurred in up to 58% of patients in at least some attacks and in up to 42% of patients in all attacks.

One study of 735 consecutive migraine patients reported that chest symptoms are frequent, but rarely important adverse effects of (primarily subcutaneous) sumatriptan. The risk of chest symptoms was reported to be patient dependent and not related, even opposite, to cardiovascular disease. This report contradicts the hypothesis that chest symptoms after sumatriptan are caused by cardiac ischemia.

Another study of 125 patients concluded that panic-like symptoms may explain the chest pain and related side effects after sumatriptan administration in patients with high levels of anxiety.

Common (1% to 10%): Chest pain/tightness/pressure and/or heaviness, flushing, neck/throat/jaw pain/tightness/pressure, transient increases in blood pressure (arising soon after treatment)

Uncommon (0.1% to 1%): Bradycardia, hypertension, hypotension, palpitations, pulsating sensations, tachycardia, various transient ECG changes (nonspecific ST or T-wave changes, prolongation of PR or QTc intervals, sinus arrhythmia, nonsustained ventricular premature beats, isolated junctional ectopic beats, atrial ectopic beats, delayed activation of the right ventricle)

Rare (less than 0.1%): Abnormal pulse, arrhythmia, pallor, Raynaud's phenomenon, vasodilation

Frequency not reported: Abdominal aortic aneurysm, angina, atherosclerosis, cerebrovascular lesion, coronary artery vasospasm, edema, heart block, peripheral cyanosis, phlebitis, thrombosis, transient myocardial ischemia

Postmarketing reports: Cyanosis, hypotension, myocardial infarction, palpitations

Very common (10% or more): Dizziness (10%), abnormal taste (20%; nasal powder)

Common (1% to 10%): Bad/unusual taste, drowsiness/sedation, dystonia, headache, hypoesthesia, paraesthesia (all types), tremor

Uncommon (0.1% to 1%): Syncope

Rare (less than 0.1%): Difficulties in concentration, disturbances of smell, dysarthria, dysesthesia, hyperesthesia, monoplegia/diplegia, myoclonia, transient hemiplegia

Frequency not reported: Bradylogia, cerebral ischemia, cerebrovascular lesion, cluster headache, convulsions, facial paralysis, incoordination, increased alertness, memory disturbance, migraine, motor dysfunction, neuralgia, nystagmus, paralysis, radiculopathy, raised intracranial pressure, seizures, speech disturbance

Postmarketing reports: Central nervous system vasculitis, cerebellar infarction, cerebrovascular accident, subarachnoid hemorrhage, serotonin syndrome, temporal arteritis

Cerebral hemorrhage, subarachnoid hemorrhage, and stroke have occurred with 5-HT1 treatment; some have resulted in fatalities. One case of sumatriptan-induced cortical stroke has been reported in a patient with sagittal sinus thrombosis. In some cases, it appears possible that the cerebrovascular events were primary, and the 5-HT1 agonist administered in the belief that presenting symptoms were due to migraine when they were not. Patients with migraine may also be at an increased risk of certain cerebrovascular events such as stroke, hemorrhage, and transient ischemic attacks.

Medication overuse headache may present as migraine-like headaches or as a marked increase in frequency of migraine attacks.

Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). The onset of symptoms generally occurs within minutes to hours of receiving a new or a greater dose of a serotoninergic medications.

Seizures have been reported in patients with either a history of seizures or concurrent conditions predisposing to seizures and also in patients where no such predisposing factors are apparent.

Common (1% to 10%): Abdominal discomfort, dysphagia, nausea and/or vomiting

Uncommon (0.1% to 1%): Diarrhea, gastroesophageal reflux

Rare (less than 0.1%): Flatulence/eructation, gallstones, peptic ulcer, retching

Frequency not reported: Abdominal distention, colitis, constipation, dental pain, disorder of mouth and tongue (e.g., burning of tongue, numbness of tongue, dry mouth), dyspeptic symptoms, feelings of gastrointestinal pressure, gastritis, gastroenteritis, gastrointestinal bleeding, gastrointestinal pain, hematemesis, hypersalivation, hyposalivation, intestinal obstruction, ischemic colitis, melena, oral itching and irritation, pancreatitis, salivary gland swelling, swallowing disorders

It is unclear whether the nausea and vomiting is related to sumatriptan therapy or to the underlying condition.

One report has suggested that "throat tightness" and chest pain associated with sumatriptan may sometimes be attributable to changes in esophageal motility.

Very common (10% or more): Atypical sensations such as tingling, warm or hot sensations, vertigo

Common (1% to 10%): Atypical sensations such as burning sensation, chills, facial pain, fatigue, feeling of pressure, feeling strange, jaw discomfort, malaise, neck pain/stiffness, numbness, pain and other pressure sensations, pain where the location is specified, prickling sensations, stinging sensations, sensation of lightness, tight feeling in head, tightness or heaviness, weakness

Rare (less than 0.1%): Fever, intoxication, simultaneous hot and cold sensations, swelling of the extremities, tickling sensations

Frequency not reported: Abortion, contusions, ear infection, ear, nose, and throat hemorrhage, external otitis, feeling of fullness in the ear(s), hearing disturbances, hearing loss, Meniere's disease, otalgia, overdose, photophobia, sensitivity to noise, swelling of face, tinnitus

Postmarketing reports: Deafness

Very common (10% or more): Application site pain (26%; transdermal patch)

Common (1% to 10%): Sweating, allergic contact dermatitis and application site paresthesia/pruritus/warmth/discomfort/irritation/site discoloration (transdermal patch)

Uncommon (0.1% to 1%): Eruptions, erythema, pruritus, skin rashes

Rare (less than 0.1%): Skin tenderness

Frequency not reported: Dry/scaly skin, eczema, hematoma, hyperhidrosis, seborrheic dermatitis, skin nodules, tightness of skin, wrinkling of skin

Postmarketing reports: Allergic vasculitis, angioedema, exacerbation of sunburn, photosensitivity, urticaria, burns scars, severe redness, pain, skin discoloration, blistering and cracked skin with the iontophoretic transdermal system

Burns and scars have been reported on the skin where the transdermal iontophoretic transdermal system has been worn. These reports describe severe redness, pain, skin discoloration, blistering, and cracked skin. On June 13, 2016, the manufacturer of the patch suspended sales and distribution of the patch to investigate the cause of these reports.

Frequency not reported: Elevated thyrotropin stimulating hormone (TSH) levels, endocrine cysts, lumps, and masses, hypothyroidism

Rare (less than 0.1%): Dysmenorrhea, dysuria

Frequency not reported: Abnormal menstrual cycle, bladder inflammation, breast swelling, breast tenderness, cysts, disorder of breasts, endometriosis, galactorrhea, hematuria, increased urination, inflammation of fallopian tubes, intermenstrual bleeding, lumps, masses of breasts, menstruation symptoms, micturition disorders, nipple discharge, urethritis, urinary infections

Frequency not reported: Anemia, lymphadenopathy

Postmarketing reports: Hemolytic anemia, pancytopenia, thrombocytopenia

Uncommon (0.1% to 1%): Minor disturbances in liver function tests

Frequency not reported: Hypersensitivity reactions ranging from cutaneous hypersensitivity to anaphylaxis

Rare (less than 0.1%): Influenza

Frequency not reported: Herpes

Very common (10% or more): Injection site reaction

Common (1% to 10%): Burning sensation (nasal administration)

Frequency not reported: Injection site stinging/burning, swelling, erythema, bruising, and bleeding

Postmarketing reports:

-Following subcutaneous administration: Contusion, induration, lipoatrophy, lipohypertrophy, pain, redness, stinging, subcutaneous bleeding, swelling

Local irritative symptoms were reported in clinical trials with sumatriptan nasal spray in approximately 5% of patients, and were severe in about 1% of cases. Symptoms were noted as being transient and generally resolved in less than 2 hours.

Uncommon (0.1% to 1%): Thirst

Rare (less than 0.1%): Dehydration, hunger, polydipsia, reduced appetite

Frequency not reported: Fluid disturbances, fluid retention, hyperglycemia, hypoglycemia, weight gain, weight loss

Common (1% to 10%): Muscle cramps, myalgia

Uncommon (0.1% to 1%): Joint disturbances (pain, stiffness, swelling, ache)

Rare (less than 0.1%): Backache, muscle stiffness, muscle tiredness, need to flex calf muscles

Frequency not reported: Acquired musculoskeletal deformity, arthralgia, arthritis, articular rheumatitis, difficulty in walking, intervertebral disc disorder, muscle atrophy, muscle tightness and rigidity, musculoskeletal inflammation, rigidity, tetany, twitching

Loss of vision included reports of permanent defects. Causality has not been established as visual disorders may occur during a migraine attack itself.

Common (1% to 10%): Vision alterations

Uncommon (0.1% to 1%): Irritation of the eye, lacrimation, photophobia

Frequency not reported: Accommodation disorders, blindness, conjunctivitis, diplopia. disorders of sclera, low vision, eye edema and swelling, eye hemorrhage, eye itching, eye pain, external ocular muscle disorders, flickering, keratitis, mydriasis, scotoma, visual disturbances

Postmarketing reports: Ischaemic optic neuropathy, retinal artery occlusion, retinal vein thrombosis

Frequency not reported: Neoplasm of pituitary, primary malignant breast neoplasm

Common (1% to 10%): Anxiety

Uncommon (0.1% to 1%): Agitation, euphoria, mental confusion, relaxation

Rare (less than 0.1%): Depression, globus hystericus, hysteria, sleep disturbance

Frequency not reported: Aggressiveness, apathy, depressive disorders, detachment, disturbance of emotions, drug abuse, hallucinations, neurotic disorders, personality change, phobia, psychomotor disorders, stress, suicide

Rare (less than 0.1%): Renal calculus

Postmarketing reports: Acute renal failure

The consequences of repeated and prolonged use of the nasal spray on nasal and/or respiratory mucosa have not been established.

Very common (10% or more): Nasal discomfort (up to 11%; nasal powder)

Common (1% to 10%): Bronchospasm, disorder/discomfort of nasal cavity/sinuses (nasal administration, subcutaneous administration), dyspnea, throat discomfort (nasal administration); rhinitis (nasal administration), rhinorrhea (nasal administration)

Rare (less than 0.1%): Diseases of the lower respiratory tract, hiccoughs, yawning

Frequency not reported: Allergic rhinitis, asthma, breathing disorder, bronchitis, cough, nasal inflammation, sinusitis, upper respiratory tract inflammation, voice disturbances

Postmarketing reports: Shortness of breath (as part of hypersensitivity reaction)