A comparative study of the activity of a new agent, indapamide, in essential arterial hypertension

A single-blind crossover trial was carried out in 38 elderly, hospitalised patients with essential hypertension to compare the hypotensive activity of 5 mg. indapamide daily with 100 mg. chlorthalidone daily. After initial treatment for 10 days with placebo, patients received treatment for 45 days with either indapamide or chlorthalidone and were then crossed over to the alternative drug for a similar period. Potassium supplementation was necessary in 25 of the patients receiving chlorthalidone, but was precribed as a precautionary measure in only 1 patients whilst on indapamide. Results showed that there were significant drops in blood pressure following both active medications, but that the percentage reduction in diastolic pressure was greater after indapamide. Indapamide also proved more effective than chlorthalidone in controlling the patients' subjective and functional symptoms of their hypertension. In an overall assessment of the effectiveness of both drugs, indapamide was judged to be better tolerated as well as more effective than chlorthalidone in 18 of the 38 patients, whilst chlorthalidone was preferred in only 7 instances.