First‐ and second‐generation H₁ antihistamines: from the molecular basis of their interaction with HERG K⁺ channels to physiological and pathophysiological implication

Summary The present article reports on the recent findings addressing the molecular basis for some rare but serious cardiovascular side‐effects exerted by some non‐sedating H 1 ‐blocking antihistamines. These latest developments, which have allowed fundamental insights into the role played by a specific class of potassium channels, the so‐called human ether‐a‐gogo‐related gene (HERG) channels, in the regulation of cardiac action potential duration and rhythm regulation, have also opened new areas of investigation into its participation in neuronal and endocrine (adenohypophyseal, chromaffin, and pancreatic) cells functioning.