Long-term follow-up of minoxidil therapy in refractory hypertension. A prospective trial in patients with various degrees of renal insufficiency.

Thirty patients with various degrees of renal insufficiency (4 on dialysis treatment) and severe hypertension refractory to conventional agents were treated with minoxidil and followed for up to 182 weeks. BP averaging 203 +/- 8.8/125 +/- 4.1 mm Hg supine and 194 +/- 7.8/125 +/- 3.9 upright before treatment, fell to 155 +/- 6.2/92 +/- 3.4 and 146 +/- 6.3/92 +/- 3.2 respectively within 1 week with 5 to 30 mg daily of minoxidil and remained stabilized around these normal values for three years or more. However, increasing doses of the drug became necessary after 52 weeks of therapy. Serum creatinine increased slightly during long-term treatment in most patients suggesting that the fall in renal function with time should be attributed to the natural progression of normotensive chronic renal failure. Adequate dialysis (in the 4 dialyzed patients) and high-ceiling diuretics prevented fluid imbalance during minoxidil therapy, while beta-blocking agents allowed complete control of reflex tachycardia.