Imitrex injection

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended. Overuse of migraine headache medicine can actually make your headaches worse.

Sumatriptan is injected under the skin. You may be shown how to use injections at home. Do not give yourself this medicine if you do not understand how to use the injection and properly dispose of used needles and syringes.

Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

Use sumatriptan as soon as you notice headache symptoms, or after an attack has already begun.

Your blood pressure will need to be checked often.

Sumatriptan injection comes in a vial (bottle), an auto-injector or prefilled cartridge to be loaded into an auto-injector syringe, or in a needle-free injector device. Each vial, cartridge, or needle-free device is for one use only.

After using an injection: If your headache does not completely go away after the injection, call your doctor before using a second sumatriptan injection. If your headache goes away and then comes back, you may use a second injection if it has been at least one (1) hour since your first injection. Do not use more than two (2) injections in 24 hours. If your symptoms do not improve, contact your doctor before using any more injections.

Use a disposable needle and syringe only once. Follow any state or local laws about throwing away used needles and syringes. Use a puncture-proof "sharps" disposal container (ask your pharmacist where to get one and how to throw it away). Keep this container out of the reach of children and pets.

Store at room temperature away from moisture, heat, and light. Throw away any unused medicine after the expiration date on the label has passed.

Using sumatriptan while you are using certain other medicines can cause high levels of serotonin to build up in your body, a condition called "serotonin syndrome," which can be fatal. Tell your doctor if you also use:

• medicine to treat depression;

• medicine to treat a psychiatric disorder;

• a narcotic (opioid) medication; or

• medicine to prevent nausea and vomiting.

This list is not complete. Other drugs may interact with sumatriptan, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Ergot-containing Drugs

Ergot-containing drugs have been reported to cause prolonged vasospastic reactions. Because these effects may be additive, use of ergotamine-containing or ergot-type medications (like dihydroergotamine or methysergide) and Imitrex Injection within 24 hours of each other is contraindicated.

Monoamine Oxidase-A Inhibitors

MAO-A inhibitors increase systemic exposure by 2-fold. Therefore, the use of Imitrex Injection in patients receiving MAO-A inhibitors is contraindicated [see Clinical Pharmacology (12.3)].

Other 5-HT1 Agonists

Because their vasospastic effects may be additive, co-administration of Imitrex Injection and other 5-HT1 agonists (e.g., triptans) within 24 hours of each other is contraindicated.

Selective Serotonin Reuptake Inhibitors/Serotonin Norepinephrine Reuptake Inhibitors and Serotonin Syndrome

Cases of serotonin syndrome have been reported during co-administration of triptans and SSRIs, SNRIs, TCAs, and MAO inhibitors [see Warnings and Precautions (5.7)].

Since Imitrex is used as needed, it does not have a daily dosing schedule. Call your doctor promptly if your symptoms do not improve after using this medicine.

After taking an Imitrex tablet, you must wait two (2) hours before taking a second tablet. Do not take more than 200 mg of sumatriptan tablets in 24 hours.

After using Imitrex nasal spray, you must wait two (2) hours before using a second spray. Do not use more than 40 mg of sumatriptan nasal spray in 24 hours.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using Imitrex and call your doctor if you have:

• sudden and severe stomach pain and bloody diarrhea;

• severe headache, pounding in your neck or ears, severe chest pain, shortness of breath, irregular heartbeats;

• a seizure (convulsions);

• blood circulation problems - cramps in your hips or legs, tight or heavy feeling in your legs, numbness or tingling in your legs, muscle weakness, burning pain in your feet, pale or blue-colored appearance in your toes;

• heart attack symptoms - chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;

• signs of a stroke - sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance; or

• high levels of serotonin in the body - agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.

Common Imitrex side effects may include:

• pain or tight feeling in your chest, throat, or jaw;

• pressure or heavy feeling in any part of your body;

• numbness or tingling, feeling hot or cold;

• dizziness, drowsiness, weakness;

• unusual or unpleasant taste in your mouth after using the nasal medicine;

• burning, numbness, pain or other irritation in your nose or throat after using the nasal medicine; or

• runny or stuffy nose after using the nasal medicine.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Common side effects of Imitrex 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: nasal capsule, nasal spray, oral tablet, subcutaneous kit, subcutaneous solution, transdermal film extended release

General

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.[Ref]

Cardiovascular

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.[Ref]

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[Ref]

Nervous system

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[Ref]

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.[Ref]

Gastrointestinal

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[Ref]

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.[Ref]

Other

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[Ref]

Dermatologic

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[Ref]

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.[Ref]

Endocrine

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

Genitourinary

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[Ref]

Hematologic

Frequency not reported: Anemia, lymphadenopathy
Postmarketing reports: Hemolytic anemia, pancytopenia, thrombocytopenia[Ref]

Hepatic

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

Hypersensitivity

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

Immunologic

Rare (less than 0.1%): Influenza
Frequency not reported: Herpes[Ref]

Local

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[Ref]

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.[Ref]

Metabolic

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[Ref]

Musculoskeletal

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[Ref]

Ocular

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

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[Ref]

Oncologic

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

Psychiatric

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[Ref]

Renal

Rare (less than 0.1%): Renal calculus
Postmarketing reports: Acute renal failure[Ref]

Respiratory

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

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)[Ref]

Some side effects of sumatriptan may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Use only after a clear diagnosis of migraine has been established

Oral:
Initial dose: 25 mg, 50 mg, or 100 mg orally, once
-If some response to first dose occurs, a second dose may be administered at least 2 hours after first dose if needed
-Oral doses of 50 and 100 mg may provide greater relief than 25 mg; however, a 100 mg dose may not provide greater effect than a 50 mg dose
Maximum dose: 200 mg per 24 hours

Subcutaneous:
Initial dose: 1 to 6 mg subcutaneously, once
-If some response to first dose occurs, a second dose may be administered at least 1 hour after first dose if needed.
Maximum dose: 12 mg per 24 hours

Intranasal:
Nasal spray: Initial dose: 5 mg, 10 mg, or 20 mg into one nostril, once
-Administer the 5 and 20 mg doses as a single spray in 1 nostril; the 10 mg dose may be administered as 5 mg into each nostril
-If some response to first dose occurs, a second dose may be administered at least 2 hours after first dose if needed
Maximum dose: 40 mg per 24 hours

Nasal capsule/powder: Initial dose: 11 mg into each nostril via Xsail (R) breath-powered delivery device once
-If symptoms have not resolved in 2 hours, or return after transient improvement a second dose may be administered at least 2 hours after the first dose
Maximum dose: 2 doses (44 mg/4 nosepieces) per 24 hours

Comments:
-Treatment should be started at the first sign of a migraine headache, or associated symptoms such as nausea, vomiting, or photophobia; this drug should not be used for migraine prophylaxis.
-Higher doses may have a greater effect, but also carry a greater risk of adverse reactions.
-The safety of treating an average of more than 4 headaches in a 30 day period has not been established.

Use: For the acute treatment of migraine with or without aura.

Data not available

Zecuity(R) was voluntarily withdrawn from the market by the manufacturer in June 2016 due to reports of serious application site reactions associated with use of this iontophoretic transdermal system. Since marketing of the patch in September 2015, there have been a number of reports in which patients describe severe redness, cracked skin, blistering or welts, and burns or scars where the patch was worn. Many report resolution within hours to weeks, although there are reports of unresolved skin reactions, typically skin discoloration.

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Data not available

Sumatriptan is thought to work in migraine by binding to certain types of serotonin receptors (specifically 5‑HT1B/1D), which results in the constriction of cranial blood vessels and the inhibition of pro-inflammatory substances, relieving the symptoms of migraine.

IMITREX Injection should only be used where a clear diagnosis of migraine or cluster headache has been established. The prescriber should be aware that cluster headache patients often possess one or more predictive risk factors for coronary artery disease (CAD).

Risk of Myocardial Ischemia and/or Infarction and Other Adverse Cardiac Events: Sumatriptan should not be given to patients with documented ischemic or vasospastic CAD (see CONTRAINDICATIONS ). It is strongly recommended that sumatriptan not be given to patients in whom unrecognized CAD is predicted by the presence of risk factors (e.g., hypertension, hypercholesterolemia, smoker, obesity, diabetes, strong family history of CAD, female with surgical or physiological menopause, or male over 40 years of age) unless a cardiovascular evaluation provides satisfactory clinical evidence that the patient is reasonably free of coronary artery and ischemic myocardial disease or other significant underlying cardiovascular disease. The sensitivity of cardiac diagnostic procedures to detect cardiovascular disease or predisposition to coronary artery vasospasm is modest, at best. If, during the cardiovascular evaluation, the patient's medical history or electrocardiographic investigations reveal findings indicative of or consistent with coronary artery vasospasm or myocardial ischemia, sumatriptan should not be administered (see CONTRAINDICATIONS ).

For patients with risk factors predictive of CAD who are determined to have a satisfactory cardiovascular evaluation, it is strongly recommended that administration of the first dose of sumatriptan injection take place in the setting of a physician's office or similar medically staffed and equipped facility. Because cardiac ischemia can occur in the absence of clinical symptoms, consideration should be given to obtaining on the first occasion of use an electrocardiogram (ECG) during the interval immediately following IMITREX Injection, in these patients with risk factors.

It is recommended that patients who are intermittent long-term users of sumatriptan and who have or acquire risk factors predictive of CAD, as described above, undergo periodic interval cardiovascular evaluation as they continue to use sumatriptan. In considering this recommendation for periodic cardiovascular evaluation, it is noted that patients with cluster headache are predominantly male and over 40 years of age, which are risk factors for CAD.

The systematic approach described above is intended to reduce the likelihood that patients with unrecognized cardiovascular disease will be inadvertently exposed to sumatriptan.

Drug-Associated Cardiac Events and Fatalities:   Serious adverse cardiac events, including acute myocardial infarction, life-threatening disturbances of cardiac rhythm, and death have been reported within a few hours following the administration of IMITREX Injection or IMITREX (sumatriptan succinate) Tablets. Considering the extent of use of sumatriptan in patients with migraine, the incidence of these events is extremely low.

The fact that sumatriptan can cause coronary vasospasm, that some of these events have occurred in patients with no prior cardiac disease history and with documented absence of CAD, and the close proximity of the events to sumatriptan use support the conclusion that some of these cases were caused by the drug. In many cases, however, where there has been known underlying CAD, the relationship is uncertain.

Premarketing Experience With Sumatriptan:   Among the more than 1,900 patients with migraine who participated in premarketing controlled clinical trials of subcutaneous sumatriptan, there were 8 patients who sustained clinical events during or shortly after receiving sumatriptan that may have reflected coronary artery vasospasm. Six of these 8 patients had ECG changes consistent with transient ischemia, but without accompanying clinical symptoms or signs. Of these 8 patients, 4 had either findings suggestive of CAD or risk factors predictive of CAD prior to study enrollment.

Of 6,348 patients with migraine who participated in premarketing controlled and uncontrolled clinical trials of oral sumatriptan, 2 experienced clinical adverse events shortly after receiving oral sumatriptan that may have reflected coronary vasospasm. Neither of these adverse events was associated with a serious clinical outcome.

Among approximately 4,000 patients with migraine who participated in premarketing controlled and uncontrolled clinical trials of sumatriptan nasal spray, 1 patient experienced an asymptomatic subendocardial infarction possibly subsequent to a coronary vasospastic event.

Postmarketing Experience With Sumatriptan:   Serious cardiovascular events, some resulting in death, have been reported in association with the use of IMITREX Injection or IMITREX Tablets. The uncontrolled nature of postmarketing surveillance, however, makes it impossible to determine definitively the proportion of the reported cases that were actually caused by sumatriptan or to reliably assess causation in individual cases. On clinical grounds, the longer the latency between the administration of IMITREX and the onset of the clinical event, the less likely the association is to be causative. Accordingly, interest has focused on events beginning within 1 hour of the administration of IMITREX.

Cardiac events that have been observed to have onset within 1 hour of sumatriptan administration include: coronary artery vasospasm, transient ischemia, myocardial infarction, ventricular tachycardia and ventricular fibrillation, cardiac arrest, and death.

Some of these events occurred in patients who had no findings of CAD and appear to represent consequences of coronary artery vasospasm. However, among domestic reports of serious cardiac events within 1 hour of sumatriptan administration, the majority had risk factors predictive of CAD and the presence of significant underlying CAD was established in most cases (see CONTRAINDICATIONS ).

Drug-Associated Cerebrovascular Events and Fatalities: Cerebral hemorrhage, subarachnoid hemorrhage, stroke, and other cerebrovascular events have been reported in patients treated with oral or subcutaneous sumatriptan, and some have resulted in fatalities. The relationship of sumatriptan to these events is uncertain. In a number of cases, it appears possible that the cerebrovascular events were primary, sumatriptan having been administered in the incorrect belief the symptoms experienced were a consequence of migraine when they were not. As with other acute migraine therapies, before treating headaches in patients not previously diagnosed as migraineurs, and in migraineurs who present with atypical symptoms, care should be taken to exclude other potentially serious neurological conditions. It should also be noted that patients with migraine may be at increased risk of certain cerebrovascular events (e.g., cerebrovascular accident, transient ischemic attack).

Other Vasospasm-Related Events:   Sumatriptan may cause vasospastic reactions other than coronary artery vasospasm. Both peripheral vascular ischemia and colonic ischemia with abdominal pain and bloody diarrhea have been reported. Very rare reports of transient and permanent blindness and significant partial vision loss have been reported with the use of sumatriptan. Visual disorders may also be part of a migraine attack.

Increase in Blood Pressure:   Significant elevation in blood pressure, including hypertensive crisis, has been reported on rare occasions in patients with and without a history of hypertension. Sumatriptan is contraindicated in patients with uncontrolled hypertension (see CONTRAINDICATIONS ). Sumatriptan should be administered with caution to patients with controlled hypertension as transient increases in blood pressure and peripheral vascular resistance have been observed in a small proportion of patients.

Concomitant Drug Use:   In patients taking MAO-A inhibitors, sumatriptan plasma levels attained after treatment with recommended doses are nearly double those obtained under other conditions. Accordingly, the coadministration of sumatriptan and an MAO-A inhibitor is not generally recommended. If such therapy is clinically warranted, however, suitable dose adjustment and appropriate observation of the patient is advised (see CLINICAL PHARMACOLOGY ).

Use in Women of Childbearing Potential:   (see PRECAUTIONS )

Hypersensitivity:   Hypersensitivity (anaphylaxis/anaphylactoid) reactions have occurred on rare occasions in patients receiving sumatriptan. Such reactions can be life threatening or fatal. In general, hypersensitivity reactions to drugs are more likely to occur in individuals with a history of sensitivity to multiple allergens (see CONTRAINDICATIONS ).