New developments in the pharmacotherapy of tension-type headaches.

The first International Headache Society classification defined tension-type headaches (TTHs) by itemising those characteristics of migraines TTHs did not possess [1]. As a result, TTHs, both episodic and chronic, remain the most nonspecific of all the commonly observed primary headaches. Until recently, there has been little impetus on the part of the pharmaceutical industry to investigate TTHs; many of the potentially useful drugs are now generic and unprofitable. In addition, few investigators have pursued the study of TTHs in lieu of its more glamorous neighbour, migraine. As a result, there are few well-designed studies on the pharmacotherapy of TTHs. The few studies that exist support the use of age-old standard drug classes, the tricyclic antidepressants and the NSAIDs. New research is now emerging that points to the potential utility of botulinum toxin type A, NMDA-receptor antagonists including Mg(2+) and nitric oxide synthase inhibitors. More scientifically rigorous clinical studies are needed.