Imitrex

Imitrex Information

Brand Name: Imitrex

Generic Name: Sumatriptan Succinate, Generic Imitrex

Other Common Names: Imigran

Imitrex (sumatriptan succinate) tablets are indicated for the acute treatment of migraine attacks with or without aura in adults.

Imitrex (sumatriptan succinate) tablets are not intended for the prophylactic therapy of migraine or for use in the management of hemiplegic or basilar migraine. Safety and effectiveness of Imitrex (sumatriptan succinate) tablets have not been established for cluster headache, which is present in an older, predominantly male population.

Injection:

Imitrex (Sumatriptan succinate) injection is intended to relieve your migraine or cluster headache, but not to prevent or reduce the number of attacks you experience. Use sumatriptan succinate injection only to treat an actual migraine or cluster headache attack.

Tablets:

Imitrex (Sumatriptan succinate) tablets are intended to relieve your migraine, but not to prevent or reduce the number of attacks you experience. Use sumatriptan succinate tablets only to treat an actual migraine attack.

Nasal Spray:

Imitrex (Sumatriptan succinate) nasal spray is intended to relieve your migraine, but not to prevent or reduce the number of attacks you experience. Use sumatriptan nasal spray only to treat an actual migraine attack.

Imitrex Ingredients and Composition

How Does Imitrex Work?

Mechanism of Action

Sumatriptan, the active ingredient in Imitrex, is an agonist for a vascular 5-hydroxytryptamine1 receptor subtype (probably a member of the 5-HT1D family) having only a weak affinity for 5-HT1A, 5-HT5A, and 5-HT7 receptors and no significant affinity (as measured using standard radioligand binding assays) or pharmacological activity at 5-HT2, 5-HT3 or 5-HT4 receptor subtypes or at alpha1-, alpha2-, or beta-adrenergic, dopamine1,; dopamine2; muscarinic, or benzodiazepine receptors.

The vascular 5-HT1 receptor subtype that sumatriptan (Imitrex) activates is present on cranial arteries in both dog and primate, on the human basilar artery, and in the vasculature of human dura mater and mediates vasoconstriction. This action in humans correlates with the relief of migraine headache. In addition to causing vasoconstriction, experimental data from animal Imitrex studies show that sumatriptan also activates 5-HT1 receptors on peripheral terminals of the trigeminal nerve innervating cranial blood vessels. Such an action may contribute to the antimigrainous effect of sumatriptan in humans.

In the anesthetized dog, Imitrex selectively reduces the carotid arterial blood flow with little or no effect on arterial blood pressure or total peripheral resistance. In the cat, Imitrex selectively constricts the carotid arteriovenous anastomoses while having little effect on blood flow or resistance in cerebral or extracerebral tissues.

How To Take Imitrex and Imitrex Dosage and Administration

In controlled clinical trials, single doses of 25, 50, or 100 mg of Imitrex (sumatriptan succinate) tablets were effective for the acute treatment of migraine in adults. There is evidence that doses of 50 and 100 mg may provide a greater effect than 25 mg. There is also evidence that doses of 100 mg do not provide a greater effect than 50 mg. Individuals may vary in response to doses of Imitrex (sumatriptan succinate) tablets. The choice of dose should therefore be made on an individual basis, weighing the possible benefit of a higher dose with the potential for a greater risk of adverse events.

If the headache returns or the patient has a partial response to the initial Imitrex dose, the dose may be repeated after 2 hours, not to exceed a total daily dose of 200 mg. If a headache returns following an initial treatment with sumatriptan succinate injection, additional single sumatriptan succinate Imitrex tablets (up to 100 mg/day) may be given with an interval of at least 2 hours between tablet doses. The safety of treating an average of more than 4 headaches in a 30-day period has not been established.

Because of the potential of MAO-A inhibitors to cause unpredictable elevations in the bioavailability of oral sumatriptan, their combined use is contraindicated.

Hepatic disease/functional impairment may also cause unpredictable elevations in the bioavailability of orally administered sumatriptan. Consequently, if treatment is deemed advisable in the presence of liver disease, the maximum single Imitrex dose should in general not exceed 50 mg.

If you suspect a Imitrex Overdose

Patients (n=670) have received single oral Imitrex doses of 140 to 300 mg without significant adverse effects. Volunteers (n=174) have received single oral doses of 140 to 400 mg without serious adverse events.

Imitrex overdose in animals has been fatal and has been heralded by:

convulsions
tremor
paralysis
inactivity
ptosis
erythema of the extremities
abnormal respiration
cyanosis
ataxia
mydriasis
salivation
lacrimation

The elimination half-life of Imitrex (sumatriptan) is approximately 2.5 hours, and therefore monitoring of patients after overdose with sumatriptan succinate tablets should continue for at least 12 hours or while symptoms or signs persist.

It is unknown what effect hemodialysis or peritoneal dialysis has on the serum concentrations of sumatriptan.

Imitrex Side Effects

Imitrex Warnings

Imitrex Precautions and Contraindications

General

Chest discomfort and wjaw or neck tightness have been reported following use of Imitrex (sumatriptan succinate) tablets and have also been reported infrequently following administration of sumatriptan nasal spray. Chest, jaw, or neck tightness is relatively common after administration of Imitrex (sumatriptan succinate) injection. Only rarely have these symptoms been associated with ischemic ECG changes. However, because sumatriptan may cause coronary artery vasospasm, patients who experience signs or symptoms suggestive of angina following Imitrex (sumatriptan succinate) should be evaluated for the presence of CAD or a predisposition to Prinzmetal's variant angina before receiving additional doses of sumatriptan, and should be monitored electrocardiographically if dosing is resumed and similar symptoms recur. Similarly, patients who experience other symptoms or signs suggestive of decreased arterial flow, such as ischemic bowel syndrome or Raynaud's syndrome.

Imitrex (sumatriptan succinate) should also be administered with caution to patients with diseases that may alter the absorption, metabolism, or excretion of drugs, such as impaired hepatic or renal function.

There have been rare reports of seizure following administration of Imitrex (sumatriptan succinate). Sumatriptan should be used with caution in patients with a history of epilepsy or structural brain lesions that lower their seizure threshold.

Care should be taken to exclude other potentially serious neurologic conditions before treating headache in patients not previously diagnosed with migraine headache or who experience a headache that is atypical for them. There have been rare reports where patients received Imitrex (sumatriptan succinate) for severe headaches that were subsequently shown to have been secondary to an evolving neurologic lesion.

For a given attack, if a patient does not respond to the first dose of Imitrex (sumatriptan succinate), the diagnosis of migraine should be reconsidered before administration of a second dose.

Contraindications to Imitrex

Imitrex (Sumatriptan succinate) tablets should not be given to patients with history, symptoms, or signs of ischemic cardiac, cerebrovascular, or peripheral vascular syndromes. In addition, patients with other significant underlying cardiovascular diseases should not receive Imitrex (Sumatriptan succinate) tablets. Ischemic cardiac syndromes include, but are not limited to, angina pectoris of any type (e.g., stable angina of effort and vasospastic forms of angina such as the Prinzmetal variant), all forms of myocardial infarction, and silent myocardial ischemia. Cerebrovascular syndromes include, but are not limited to, strokes of any type as well as transient ischemic attacks. Peripheral vascular disease includes, but is not limited to, ischemic bowel disease.

Because Imitrex (Sumatriptan succinate) tablets may increase blood pressure, they should not be given to patients with uncontrolled hypertension.

Concurrent administration of MAO-A inhibitors or use within 2 weeks of discontinuation of MAO-A inhibitor therapy is contraindicated.

Imitrex (Sumatriptan succinate) tablets should not be administered to patients with hemiplegic or basilar migraine.

Imitrex (Sumatriptan succinate) tablets and any ergotamine-containing or ergot-type medication (like dihydroergotamine or methysergide) should not be used within 24 hours of each other, nor should sumatriptan succinate and another 5-HT1 agonist.

Imitrex (Sumatriptan succinate) tablets are contraindicated in patients with hypersensitivity to sumatriptan or any of their components.

Imitrex (Sumatriptan succinate) succinate tablets are contraindicated in patients with severe hepatic impairment.

Imitrex Drug Interactions

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

MAO-A inhibitors reduce Imitrex (sumatriptan) clearance, significantly increasing systemic exposure. Therefore, the use of Imitrex tablets in patients receiving MAO-A inhibitors is contraindicated.

Selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline) have been reported, rarely, to cause weakness, hyperreflexia, and incoordination when coadministered with sumatriptan. If concomitant treatment with Imitrex and an SSRI is clinically warranted, appropriate observation of the patient is advised.

Taking Imitrex during Pregnancy or Breast-feeding

There are no adequate and well-controlled Imitrex studies in pregnant women. Therefore, Imitrex (sumatriptan succinate) tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Imitrex and Alcohol Interaction

Alcohol consumed 30 minutes prior to sumatriptan ingestion had no effect on the pharmacokinetics of Imitrex.

Sumatriptan is excreted in human breast milk. Therefore, caution should be exercised when considering the administration of Imitrex (sumatriptan succinate) tablets to a nursing woman.

Imitrex Clinical Trials and Studies

Storing Imitrex

Store between 2-30°C (36-86°F).

Additional Patient Information for Imitrex

The generic name of your medication, Imitrex, is sumatriptan succinate. It can be obtained only with a prescription from your doctor. The decision to use sumatriptan injection, tablets, or nasal spray is one that you and your doctor should make jointly, taking into account your individual preferences and medical circumstances. If you have risk factors for heart disease (such as high blood pressure, high cholesterol, obesity, diabetes, smoking, strong family history of heart disease, or you are postmenopausal or a male over 40), you should tell your doctor, who should evaluate you for heart disease in order to determine if sumatriptan succinate is appropriate for you. Although the vast majority of those who have taken Imitre (sumatriptan succinate) have not experienced any significant side effects, some individuals have experienced serious heart problems and, rarely, considering the extensiveness of Imitrex (sumatriptan succinate) use worldwide, deaths have been reported. In all but a few instances, however, serious problems occurred in people with known heart disease and it was not clear whether sumatriptan succinate was a contributory factor in these deaths.

Additional Notes

This medication is used to relieve a migraine attack in progress. It is not effective in preventing migraine attacks.