The unsuitability of minoxidil for the treatment of moderate hypertension.

Minoxidil is very effective in the treatment of severe or resistant hypertension but fluid retention and hypertrichosis have been side-effects. This study examines the suggestion that the use of small doses of minoxidil may be effective in the treatment of moderate hypertension without causing these adverse effects. Sixteen patients with an elevated blood pressure level that was suboptimally controlled by combination therapy with diuretic and beta-adrenoreceptor blocking agents entered a randomized open trial to compare the efficacy and acceptability of minoxidil and prazosin as supplementary therapy to bendrofluazide and metoprolol. Blood pressure control was similar in the two groups. However, relatively large doses of minoxidil were required and over-all tolerance to the drug was poor; five of eight patients who were receiving minoxidil experienced marked fluid retention that necessitated a change in diuretic agent to substantial doses of frusemide. Low doses of minoxidil do not appear to be effective in the treatment of moderate hypertension, and the drug cannot be recommended for this indication.