THE ANTIHYPERTENSIVE AND METABOLIC EFFECTS OF LOW AND CONVENTIONAL DOSE CYCLOPENTHIAZIDE IN TYPE-II DIABETICS WITH HYPERTENSION

The antihypertensive efficacy and metabolic effects of cyclopenthiazide 125-mu-g were compared with cyclopenthiazide 500-mu-g in patients with non-insulin dependent diabetes and hypertension in a double blind, randomized crossover study. After a 6-week placebo period 24 patients with non-insulin dependent diabetes mellitus, stabilized on diet or oral hypoglycaemic agents, who had a mean diastolic blood pressure between 90 and 120 mmHg after receiving placebo for 6 weeks were given 125-mu-g or 500-mu-g cyclopenthiazide for 12 weeks. Patients then received placebo for a further 6-week period, following which they received the alternate treatment dosage for 12 weeks. There were no differences between doses in their antihypertensive effects. While 500-mu-g significantly reduced systolic and diastolic blood pressures, only diastolic pressure was significantly reduced by 125-mu-g from pre-treatment values. The higher dose of cyclopenthiazide had greater effects on measures of diabetic control than did the 125-mu-g dose and the rise in blood glucose after 12 weeks' treatment with 500-mu-g was significantly different from pre-treatment values. Cyclopenthiazide 125-mu-g had significantly less effect on triglycerides, potassium and urate, than did 500-mu-g. Cyclopenthiazide 500-mu-g resulted in a significant fall in serum potassium from pre-treatment values. There were no intertreatment differences in the other variables measured. Cyclopenthiazide 125-mu-g is as effective as 500-mu-g in reducing diastolic blood pressure in mildly hypertensive non-insulin dependent diabetic patients. The higher dose had more pronounced adverse effects on glucose control and serum concentrations of triglycerides, potassium and urate.