Molecule

Drug Groups

approved; investigational

Description

A serotonin agonist that acts selectively at 5HT1 receptors. It is used in the treatment of migraine disorders. A transdermal patch version of sumatriptan is currently in phase I trials in the U.S. under the code name NP101 (NuPathe).

Indication

For the treatment of migraine attacks with or without aura.

Pharmacology

Sumatriptan, an antimigraine drug, is a selective agonist of vascular serotonin ((5-hydroxytryptamine; 5-HT) type 1-like receptors, likely the 5-HT_1D and 5-HT_1B subtypes. It has no significant affinity (as measured using standard radioligand binding assays) or pharmacological activity at 5-HT2, 5-HT3 receptor subtypes or at alpha1-, alpha2-, or beta-adrenergic; dopamine1; dopamine2; muscarinic; or benzodiazepine receptors.

Toxicity

Symptoms of overdose include convulsions, tremor, paralysis, inactivity, ptosis, erythema of the extremities, abnormal respiration, cyanosis, ataxia, mydriasis, salivation, and lacrimation.

Affected Organisms

Biotransformation

Hepatic. In vitro studies with human microsomes suggest that sumatriptan is metabolized by monoamine oxidase (MAO), predominantly the A isoenzyme.

Absorption

Approximately 15%

Half Life

2.5 hours

Protein Binding

14%-21%

Elimination

Only 3% of the dose is excreted in the urine as unchanged sumatriptan; 42% of the dose is excreted as the major metabolite, the indole acetic acid analogue of sumatriptan.

Distribution

* 2.7 L/kg [subcutaneous dosing]

Clearance

* 1200 mL/min [Following a 6-mg SC injection]

References

External Links