Generic Imitrex Sumatriptan

How was Imitrex discovered?

Pharmaceutical companies had largely ignored migraine as a diagnosis, despite the size of the potential market.

The new era in antimigraine drugs began only in 1973 with efforts to synthesize a more selective serotonin agonist, following up on numerous observations implicating serotonin (a potent vasoconstrictor and a pain modulator) in the generation of a migraine attack.

GlaxoSmithKline introduced the first of the new serotonin agonists, Sumatriptan (Imitrex), in 1991. Patrick Humphrey working in the research team of GlaxoSmithKline (GSK) discovered Sumatriptan.

Note: sells generic version of Imitrex


Imitrex is a product of GlaxoSmithKline (GSK).

GlaxoSmithKline (GSK) is a world leading research-based pharmaceutical company with a powerful combination of skills and resources that provides a platform for delivering strong growth in today's rapidly changing healthcare environment.

GSK's mission is to improve the quality of human life by enabling people to do more, feel better and live longer.

Headquartered in the UK and with operations based in the US, the new company is one of the industry leaders, with an estimated seven per cent of the world's pharmaceutical market.

GSK also has leadership in four major therapeutic areas - anti-infectives, central nervous system (CNS), respiratory and gastro-intestinal/metabolic. In addition, it is a leader in the important area of vaccines and has a growing portfolio of oncology products.

The company also has a Consumer Healthcare portfolio comprising over-the-counter (OTC) medicines, oral care products and nutritional healthcare drinks, all of which are among the market leaders.

GSK has over 100,000 employees worldwide. Of these, over 40,000 are in sales and marketing, the largest sales force in the industry. Around 35,000 employees work at 82 manufacturing sites in 37 countries and over 15,000 are in R&D.

GSK R&D is based at 24 sites in 11 countries. The company has a leading position in genomics/genetics and new drug discovery technologies.


The phases of typical migraine headache

Migraine is a type of headache marked by severe head pain lasting several hours or more.

Migraine is an intense, often debilitating type of headache.

More than three million women and one million men have one or more severe headaches every month.
Migraines often begin in adolescence, and are rare after age 60.

Two types of migraine are recognized. Eighty percent of migraine sufferers experience "migraine without aura,"formerly called common migraine. In "migraine with aura," formerly called classic migraine, pain is preceded or accompanied by visual or other sensory disturbances, including hallucinations, partial obstruction of the visual field, numbness or tingling, or a feeling of heaviness. Symptoms are often most prominent on one side of the body, and may begin as early as 72 hours before the onset of pain.

Causes & symptoms

The physiological basis of migraine has proved difficult to uncover. Genetics appear to play a part for many, but not all, people with migraine. There are a multitude of potential triggers for a migraine attack, and recognizing one's own set of triggers is the key to prevention.

The most widely accepted hypothesis of migraine suggests that a migraine attack is precipitated when pain-sensing nerve cells in the brain release chemicals called neuropeptides. At least one of the neurotransmitters, substance P, increases the pain sensitivity of other nearby nociceptors.

Other neuropeptides act on the smooth muscle surrounding cranial blood vessels. This smooth muscle regulates blood flow in the brain by relaxing or contracting, thus dilating (enlarging) or constricting the enclosed blood vessels. At the onset of a migraine headache, neuropeptides are thought to cause muscle relaxation, allowing vessel dilation and increased blood flow. Other neuropeptides increase the leakiness of cranial vessels, allowing fluid leak, and promote inflammation and tissue swelling. The pain of migraine is though to result from this combination of increased pain sensitivity, tissue and vessel swelling, and inflammation. The aura seen during a migraine may be related to constriction in the blood vessels that dilate in the headache phase.

Susceptibility to migraine may be inherited. A child of a migraine sufferer has as much as a 50% chance of developing migraine. If both parents are affected, the chance rises to 70%. However, the gene or genes responsible have not been identified, and many cases of migraine have no obvious familial basis. It is likely that whatever genes are involved set the stage for migraine, and that full development requires environmental influences as well.

A wide variety of foods, drugs, environmental cues, and personal events are known to trigger migraines. It is not known how most triggers set off the events of migraine, nor why individual migraine sufferers are affected by particular triggers but not others.

Common food triggers include:

  • Cheese
  • Alcohol
  • Caffeine products, and caffeine withdrawal
  • Chocolate
  • Intensely sweet foods
  • Dairy products
  • Fermented or pickled foods
  • Citrus fruits
  • Nuts
  • Processed foods, especially those containing nitrites, sulfites, or monosodium glutamate (MSG).

Environmental and event-related triggers include:

  • Stress or time pressure
  • Menstrual periods, menopause
  • Sleep changes or disturbances, oversleeping
  • Prolonged overexertion or uncomfortable posture
  • Hunger or fasting
  • Odors, smoke, or perfume
  • Strong glare or flashing lights.

Drugs which may trigger migraine include:

  • Oral contraceptives
  • Estrogen replacement therapy
  • Nitrates
  • Theophylline
  • Reserpine
  • Nifedipine
  • Indomethicin
  • Cimetidine
  • Decongestant overuse
  • Analgesic overuse
  • Benzodiazepine withdrawal.

Migraine without aura may be preceded by elevations in mood or energy level for up to 24 hours before the attack. Other pre-migraine symptoms may include fatigue, depression, and excessive yawning.

Aura most often begins with shimmering, jagged arcs of white or colored light progressing over the visual field in the course of 10-20 minutes. This may be preceded or replaced by dark areas or other visual disturbances. Numbness and tingling is common, especially of the face and hands. These sensations may spread, and may be accompanied by a sensation of weakness or heaviness in the affected limb.

The pain of migraine is often present only on one side of the head, although it may involve both, or switch sides during attacks. The pain is usually throbbing, and may range from mild to incapacitating. It is often accompanied by nausea or vomiting, painful sensitivity to light and sound, and intolerance of food or odors. Blurred vision is common.

Migraine pain tends to intensify over the first 30 minutes to several hours, and may last from several hours to a day or longer. Afterward, the affected person is usually weary, and sensitive to sudden head movements.

Migraine is diagnosed by a careful medical history. Lab tests and imaging studies such as magnetic resonance imaging (MRI) scans have not been useful for identifying migraine. However, for some patients, those tests may be needed to rule out a brain tumor or other structural causes of migraine headache.

Once a migraine begins, the person will usually seek out a dark, quiet room to lessen painful stimuli. Imitrex may be used to reduce the pain and severity of the attack.

When is Imitrex best taken?

In clinical studies with Imitrex Tablets, up to 45 percent of patients had their migraine pain eliminated or reduced as early as 60-90 minutes after taking a 25 mg Imitrex dose.

Clinical studies also showed that up to 83 percent of migraine sufferers (range 68%-83%; average 70%) treated with Imitrex Tablets had the ability to work and function normally or to work while mildly impaired within four hours of taking Imitrex.

Imitrex Tablets have been studied in clinical trials with over 19,400 patients treating more than 102,500 migraine attacks.

How do different people react to Imitrex?

Age: The pharmacokinetics of oral Imitrex in the elderly (mean age, 72 years; 2 males and 4 females) and in patients with migraine (mean age, 38 years; 25 males and 155 females) were similar to that in healthy male subjects (mean age, 30 years).

Gender: In a study comparing females to males, no pharmacokinetic differences were observed between genders for maximum concentration, maximum time, and half-life.

Race : The systemic clearance and maximum concentration of Imitrex were similar in black (n = 34) and Caucasian (n = 38) healthy male subjects.

How does Imitrex affect your existing condition/ailment?

Renal Impairment : The effect of renal impairment on the pharmacokinetics of Imitrex has not been examined, but little clinical effect would be expected as Imitrex is largely metabolized to an inactive substance.

Hepatic Impairment : The liver plays an important role in the presystemic clearance of orally administered Imitrex. Accordingly, the bioavailability of Imitrex following oral administration may be markedly increased in patients with liver disease.

What else does Imitrex treat?

Imitrex can ONLY be used for migraine.

What are the side effects of Imitrex?

Serious cardiac events, including some that have been fatal, have occurred following the use of Imitrex. These events are extremely rare and most have been reported in patients with risk factors predictive of CAD. Events reported have included coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia, and ventricular fibrillation. Significant hypertensive episodes, including hypertensive crises, have been reported on rare occasions in patients with or without a history of hypertension.

Incidence in Controlled Clinical Trials:

The table below lists adverse events that occurred in placebo-controlled clinical trials in patients who took at least 1 dose of Imitrex.

Only events that occurred at a frequency of 2% or more in any group treated with Imitrex Tablets and were more frequent in that group than in the placebo group have been included in the table.

The events cited reflect experience gained under closely monitored conditions of clinical trials in a highly selected patient population. In actual clinical practice or in other clinical trials, these frequency estimates may not apply, as the conditions of use, reporting behavior, and the kinds of patients treated may differ.

Other, less serious side effects may be more likely to occur. Continue to use Imitrex and talk to your doctor if you experience

  • nausea;
  • drowsiness or dizziness;
  • tingling, flushing, warmth, redness, or heaviness of a body part;

Side effects other than those listed here may also occur. Talk to your doctor about any side effects that seems unusual or that is especially bothersome