Sumatriptan Succinate (Imitrex)

Sumatriptan (sumatriptan succinate) available under brand names Imitrex, Imigran, Imigran recovery is a triptan drug including a sulfonamide group for the treatment of migraine headaches. Imitrex is marketed and manufactured by GlaxoSmithKline as well as various generic drug manufacturers.
Sumatriptan is structurally similar to serotonin (5HT), and is a 5-HT (types 5-HT1D and 5-HT1B[7]) agonist. The specific receptor subtypes it activates are present on the cranial arteries and veins. Acting as an agonist at these receptors, Sumatriptan reduces the vascular inflammation associated with migraine.

Uses Of Sumatriptan Succinate (Imitrex)

Sumatriptan is used for the treatment of migraine headaches. It is not used to prevent attacks or reduce the number of migraine attacks you have. Use Imitrex Tablets only to treat an actual migraine attack.
The efficacy of Sumatriptan (Imitrex) Tablets is unaffected by presence of aura, the duration of headache prior to treatment, gender, age, or weight of the patient.

Availability And Packaging

Sumatriptan was the first triptan available (in 1991), and is available only by medical prescription. Several dosage forms for sumatriptan have been approved, including tablets, solution for injection, and nasal inhalers. On April 15, 2008, the US FDA approved a combination of sumatriptan and naproxen, an NSAID, which is marketed in the USA under the trade name Treximet. This combination has shown a benefit over either medicine used separately. Generic version of Imitrex (Sumatriptan) tablets in 25, 50, and 100 milligram doses are already available in several countries since Glaxo's patent protections have expired as of 2009 or earlier.

Sumatriptan Dosage

Single doses of 25, 50, or 100 mg of Imitrex Tablets are effective for the acute treatment of migraine in adults.
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 dose, the dose may be repeated after 2 hours, not to exceed a total daily dose of 200 mg.

Pharmacokinetics

Sumatriptan is administered in several forms; tablets, subcutaneous injection, and nasal spray. Oral administration (as succinate) suffers from poor bioavailability, partly due to presystemic metabolism — some of it gets broken down in the stomach and bloodstream before it reaches the target arteries. A new rapid-release tablet formulation has the same bioavailability, but the maximum concentration is achieved on average 10–15 minutes earlier.
When injected, sumatriptan is faster acting (usually within 10 minutes), but the effect lasts for a shorter time. Sumatriptan is metabolised primarily by monoamine oxidase A into an indole acetic acid analogue, part of which is further conjugated with glucuronic acid. These metabolites are excreted in the urine and bile. Only about 3% of the active drug may be recovered unchanged.

Side effects Of Sumatriptan

Large doses of sumatriptan (200 mg/day) can cause sulfhemoglobinemia, a rare condition in which the blood changes from red to greenish-black, due to the integration of sulfur into the hemoglobin molecule. If sumatriptan is discontinued, the condition reverses within a few weeks.
Serious cardiac events, including some that have been fatal, have occurred following the use of Imitrex Injection or Tablets. Events reported have included coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia, and ventricular fibrillation.

Further Information

Manufacturers pamphlet: GlaxoSmithKline Imitrex Information