Combination therapy in hypertension. A population-based study in eastern Finland.

In a cross-sectional study, antihypertensive drug treatment was studied in a representative population sample of people aged 30-64 years, using a combination of postal survey, personal interview, clinical assessment and drug prescriptions. 11% of the men and 16% of the women were currently taking antihypertensives; 54% of patients used one, 38% used two, and 8% used three or more preparations. Men used slightly more drugs than women. Diuretics were used by 62% and betablockers by 49% of the sample population. Fixed combinations of thiazides and potassium-sparing agents formed 70% of all diuretic preparations used. Only 12% of the patients used fixed antihypertensive combinations, of which over half were diuretic-reserpine-vasodilator combinations; women and older patients used them most often. The most common freely combined preparations were diuretics and betablockers, which formed almost half of all two-drug combinations, and were also present in 70% of all triple combinations. Adequate control of blood pressure (DBP less than 100 mmHg) was achieved by slightly under 50% of the patients, the BP of women being more adequately controlled than that of men. Differences in BP control were found between the different drugs and combinations. Antihypertensive combination therapy is important in successful treatment, but we still cannot be sure whether fixed combination preparations or, as in this study, free combinations of marketed preparations are better alternatives for treatment.