Naratriptan

Naratriptan (trade names include Amerge and Naramig) is a triptan drug marketed by GlaxoSmithKline and is used for the treatment of migraine headaches. Naratriptan is available in 2.5 mg tablets. It is a selective 5-HT1 receptor subtype agonist. Naratriptan hydrochloride is chemically designated as N-methyl-3-( 1-methyl-4-piperidinyl)-1H-indole-5-ethanesulfonamide.

Indication
Naratriptan is used for the treatment of the acute migraine attacks and the symptoms of migraine, including severe, throbbing headaches that sometimes are accompanied by nausea and sensitivity to sound or light.

Mechanism of Action
The causes of migraine are not clearly understood; however, the efficacy of naratriptans and other triptans is believed to be due to their activity as 5HT (serotonin) agonists.

Efficacy
A meta-analysis of 53 clinical trials has shown that all triptans are effective for treating migraine at marketed doses and that naratriptan, although less effective than sumatriptan and rizatriptan was more effective than placebo in reducing migraine symptoms at two hours and efficacy was demonstrated in almost two thirds of subjects after four hours of treatment.

Side effects
Side effects include: dizziness, drowsiness, tingling of the hands or feet, unusual tiredness, nausea, dry mouth and unsteadiness. If these effects persist or worsen, notify your doctor promptly. Side-effects which are unlikely and which should be promptly reported include: chest pain/pressure, throat pain/pressure, unusually fast/slow/irregular pulse, one-sided muscle weakness, vision problems, cold/bluish hands or feet, stomach pain, bloody diarrhea, mental/mood changes, and fainting. In the unlikely event you have a serious allergic reaction to this drug, seek immediate medical attention. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing.

Exclusivity
In the United States, the Food and Drug Administration (FDA) approved naratriptan on February 11, 1998. It was covered by ; the FDA lists the patent as expiring on July 7, 2010.

In July 2010, in the wake of the patent expiration, several drug manufacturers, including Roxane Labs, Sandoz and Teva Pharmaceuticals, announced that they were launching generic Naratriptan medications.

The drug continues to be covered by European patent 0303507 in Germany, Spain, France and the United Kingdom through March 10, 2012, and by Australian patent 611469 in Australia through June 17, 2013. It had previously been covered by Canadian patent 1210968; but both Sandoz and Novopharm have offered generic equivalents in Canada since that patent's expiration December 1, 2009.