to show much utility. Due to its short duration of action, it was thought that longer-acting ENaC inhibitors may prove more effective. However, longer-acting ENaC inhibitors (i.e. benzamil) have also failed clinical trials, despite an improvement in both the solubility and potency of the drugs. A third generation amiloride analogue (N-(3,5-diamino-6-chloropyrazine-2-carbonyl)-N'-4-[4-(2,3-dihydroxypropoxy)phenyl]butyl-guanidine methanesulfonate, research name "552-02"), with better pharmacokinetic properties, is being studied. Pain induced by exposure to acid is attenuated by amiloride in human trials, which may indicate a role for amiloride in the treatment of pain in the future. References External links Potassium-sparing diuretics Aminopyrazines Acylguanidines World Health Organization essential medicines Sodium channel blockers World Anti-Doping Agency prohibited substances Wikipedia medicine articles ready to translate