Current prescription status of antihypertensive drugs with special reference to the use of diuretics in Japan

The guidelines for the management of hypertension recommend the inclusion of diuretics, especially when three or more antihypertensive drugs are used. The present study investigated the current prescription status of antihypertensive drugs with a particular focus on the use of diuretics in a local district in Japan. Prescriptions, including antihypertensive drugs, were collected from a dispensing pharmacy of the Yahata Pharmacist Association, located in Kitakyushu City, in October 2014. Of the 10 585 prescriptions, calcium channel blockers (CCBs) were prescribed in 73.5%, followed by angiotensin II receptor blockers (ARB, 62.7%), diuretics (16.5%) and β-blockers (13.6%). The average number of drugs used was 1.80. The rates of prescription of diuretics for patients with one, two, three and four drugs were 0.6%, 13.1%, 55.2% and 82.6%, respectively. Diuretics were more frequently prescribed in elderly patients, and the prescription rate of doctors in hospitals was significantly higher than that of general practitioners (19.1% vs . 15.7%, P <0.01). In addition, 40% of patients with thiazide diuretics were prescribed combination tablets of hydrochlorothiazide with ARB, whereas trichlormethiazide (34.9%) and indapamide (19.8%) were used in other patients. Based on these findings, the use of diuretics remains limited, even among patients taking multiple antihypertensive drugs.