Enteric-coated potassium: why are hydrosaluric-K and salupres still marketed?

Abstract

About 1964 enteric-coated potassium chloride preparations became recognised as a specific cause of small-bowel ulceration, leading to stricture or perforation. Since then almost all manufacturers of slow-release potassium chloride supplements have used other formulations, (e. g. embedding the drug in a wax-core, as in Slow-K) with which the risk is much less, though it must still be considered in patients who already have oesophageal or small-bowel obstruction. Two preparations containing enteric-coated potassium remain available, however, though Merck Sharp & Dohme, the manufacturer, tells us that they are not promoted. The preparations are Hydrosaluric-K (hydrochlorothiazide + potassium chloride) and Salupres (hydrochlorothiazide + reserpine + potassium chloride), and cases of small-bowel ulceration associated with the use of these tablets continue to be reported,1 2 despite the warning (mandatory since 1967 for all solid preparations of potassium salts), to ‘discontinue use if symptoms or signs of small-bowel ulceration develop’.