Triptans, sold under the brandnames Imitrex, Zomig, Amerge, Maxalt, Relpax and others, are a range of highly effective drugs used to treat Migraineplugin-autotooltip__plain plugin-autotooltip_bigMigraine

"Chronic migraine has a great detrimental influence on a patient’s life, with a severe impact on socioeconomic functioning and quality of life. Chronic migraine affects 1–2% of the general population, and about 8% of patients with migraine; it usually develops from episodic migraine at an annual conversion rate of about 3%." and Cluster headacheplugin-autotooltip__plain plugin-autotooltip_bigCluster headache

"Cluster headache (CH) always involves pain that is one sided (although it can switch sides) and the main defining feature is the association with one or more of the 'cranial autonomic' features normally described as follows: • Reddening and tearing of the eye • A runny or blocked nostril • Droopy eyelid • Constriction of the pupil • Flushing and facial sweating.

The mechanism of action of the drugs has been debated since the 1980s.

It's currently thought that Triptans work by a (possible) combination of vaso-constriction and the blocking of 5-HT_1D receptors, and/or because of its effects on nitric oxide levels.

[…] there was always a debate about its mechanism of action, and it still remains unclear today."

Source : Wikipedia