Effect of equivalent antihypertensive doses of mefruside and cyclopenthiazide on serum electrolytes, uric acid and glucose tolerance in hypertensive patients.

1. A comparative cross-over trial of mefruside and cyclopenthiazide, each drug being given for 6 weeks, was conducted on thirty hypertensive patients with diabetes mellitus or impaired glucose tolerance. Other antihypertensive therapy, any antidiabetic therapy and potassium supplementation were kept constant throughout the trial. Dosages of mefruside and cyclopenthiazide were adjusted to give approximately equal blood pressure levels in the two drug periods. 2. There was no significant difference in the following parameters studied during the sixth week of each of the two periods of drug therapy: serum electrolytes, total CO2, chloride, urea, amylase, haemoglobin, erythrocyte sedimentation rate, platelet and white blood cell counts, lying and standing blood pressure and pulse rate, weight, fasting and 2-h glucose and insulin levels and five-value glucose and insulin curve areas, fasting calcium and phosphate. 3. Serum creatinine and uric acid showed a small but significant fall during mefruside therapy.