Torasemide prolonged release (PR), a high-ceiling diuretic, inhibits renal tubular reabsorption of sodium and chloride in the thick ascending limb of the loop of Henle. Relative to the immediate-release (IR) formulation, the PR formulation of torasemide was associated with similar systemic exposure, but significantly slower rates of absorption and lower fluctuations in plasma concentrations, and provided higher natriuretic efficiency and more constant diuresis. The antihypertensive efficacy of once-daily torasemide PR 5-10 mg was noninferior to that of once-daily torasemide IR 5-10 mg with regard to the change from baseline in sitting diastolic BP (primary endpoint) in a 12-week, randomized, double-blind trial in patients with mild to moderate hypertension. Sitting systolic BP (SBP) decreased from baseline to a similar extent in the overall population of the treatment groups at week 12. However, daytime SBP decreased to a significantly greater extent with torasemide PR than IR in a subgroup of patients who underwent ambulatory 24-hour BP monitoring. Patients receiving torasemide PR were more likely to achieve adequate control of BP at weeks 8 and 12 than those receiving torasemide IR. The PR formulation of torasemide was well tolerated in the clinical trial, with a tolerability profile that was similar to that with the IR formulation.