Small-molecule modulators of inward rectifier K+ channels: recent advances and future possibilities

Inward rectifier potassium (Kir) channels have been postulated as therapeutic targets for several common disorders including hypertension, cardiac arrhythmias and pain. With few exceptions, however, the small-molecule pharmacology of this family is limited to nonselective cardiovascular and neurologic drugs with off-target activity toward inward rectifiers. Consequently, the actual therapeutic potential and 'drugability' of most Kir channels has not yet been determined experimentally. The purpose of this review is to provide a comprehensive summary of publicly disclosed Kir channel small-molecule modulators and highlight recent targeted drug-discovery efforts toward Kir1.1 and Kir2.1. The review concludes with a brief speculation on how the field of Kir channel pharmacology will develop over the coming years and a discussion of the increasingly important role academic laboratories will play in this progress.