Guidelines for rational diuretic use in the elderly.

The elderly not only have lower body stores of potassium, but also tend to eat a diet relatively low in potassium content. Loss of muscle strength, constipation and mental apathy are all features of potassium deficiency. In addition, serious arrhythmias have been attributed to hypokalaemia and must therefore be prevented. While potassium supplements may replete body potassium stores, they often require large amounts and may still be ineffective in preventing diuretic-induced hypokalaemia. Thus, several guidelines for the rational and safe use of diuretics in the elderly have been proposed including in addition to potassium supplementation, the determination of dietary and total body potassium sources, dosage of the diuretic and intensity of the diuresis, and the relationship between potassium and calcium and magnesium.