A Cochrane review included 9 studies with a total of 460 subjects. The studies evaluated the dose-related blood pressure (BP) lowering efficacy of five drugs within the loop diuretics class (furosemide 40 to 60 mg, cicletanine 100 to 150 mg, piretanide 3 to 6 mg, indacrinone enantiomer -2.5 to -10.0/+80 mg and etozolin 200 mg) for a mean duration of 8.8 weeks (baseline blood pressure 162/103 mmHg). The best estimate of SBP/DBP lowering efficacy of loop diuretics was -7.9 mmHg (95% CI -10.4 to -5.4) / -4.4 mmHg (95% CI -5.9 to -2.8). There was no clinically meaningful BP lowering differences between different drugs within the loop diuretic class. Withdrawals due to adverse effects was not statistically significant (RR 1.9, 95% CI 0.3 to 10.8; 6 studies, n=331). The review did not provide a good estimate of the incidence of harms associated because of the short duration of the trials and the lack of reporting of adverse effects in many of the trials.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment) and by potential reporting bias.