Persistence and adherence to antihypertensive treatment in relation to initial prescription: diuretics versus other classes of antihypertensive drugs.

BACKGROUND The use of thiazide diuretics in the treatment of hypertension is widely considered as a first-line treatment, given the efficacy and low cost of this class of drugs. This indication is not unanimous, because thiazides can cause metabolic alterations, and other side effects that reduce compliance and persistence on treatment. OBJECTIVES In a multicentre, open-label randomized study we compared adherence and persistence to therapy of chlortalidone versus other treatments, as a first-line antihypertensive therapy. METHODS Ninety-two general practitioners (GPs) recruited 2409 hypertensive patients with indication to antihypertensive therapy, who were randomized in two arms to start treatment with chlortalidone (12.5-25 mg daily) or any other single medications (excluding thiazides). The patients have been followed for at least 2 years. RESULT Patients receiving diuretic therapy as first-line antihypertensive treatment, modified antihypertensive treatment regimen more often than the others (79.1 versus 43.9%; χ (2)< 0.0001). Patients starting with diuretics received greater number of drugs, compared to patients starting with different antihypertensive therapy (1.55 versus 1.4 antihypertensive drugs; P < 0.0001), but achieved the same blood pressure (BP) control during the follow-up. No differences were observed in persistence and adherence to treatment between the two groups. CONCLUSION Our results demonstrate that the recommendation to start antihypertensive therapy with diuretics, when no compelling indications are present, is not supported by the evidence that this strategy produces more rapid and better control of BP.