Effect of anti-hypertensive drug dose frequency on the clinic-home blood pressure difference in patients with stage 1 treated hypertension

Clinic blood pressure (CBP) is generally used for diagnosis and treatment monitoring in hypertension, but target organ damage correlates more closely with home blood pressure (HBP). Eliminating the clinic-home blood pressure difference (CHBPD) would make conventional CBP a more accurate alternative to HBP. This prospective, randomized, open trial compared the effect of a once-daily versus a twice-daily regimen of anti-hypertensive therapy on CHBPD. After a 2-week wash-out period, 85 confirmed stage 1 hypertensive patients were randomized to receive 2 mg trichlormethiazide daily in one (40 subjects) or two (45 subjects) daily doses for 3 weeks. CBP and HBP measurements were taken during the third week of treatment and the CHBPD calculated. After treatment, the systolic and diastolic CHBPD values were significantly greater in the once-daily regimen than in the twice-daily regimen. Conventional CBP should not be used as an alternative to HBP for evaluating prognosis and monitoring anti-hypertensive therapy when using a once-daily regimen.