Objective: Uncontrolled hypertension is present in most patients treated with only a single morning dose or fixed dose drug combination; usually a third of them have a high prevalence of a nondipper blood pressure pattern, especially patients with chronic illness. In most cases, nondipping is related partly to the absence of 24-h therapeutic coverage of the single morning doses. We have investigated the usefulness of shifting therapy to evening instead of the morning.
Aim: The aim of the study was to better control blood pressure and convert patients with a nondipping pattern to a dipper pattern without the need to increase the dose of their drugs or the addition of any other family of drugs.
Methods: Among 200 hypertensive patients, we investigated the impact of treatment time on the blood pressure pattern in 60 patients (33.3%) with uncontrolled hypertension with a nondipper pattern on the basis of clinic measurements who were studied by 24-h ambulatory monitoring during 2 and 4 months of follow-up; all of them received their treatment in the morning. This group of patients was divided randomly into two groups of 30 patients each; one group continued to receive the medication on awakening and the other took their medication at bedtime. Most of the treatment involved calcium channel blockers and other angiotensin-converting-enzyme inhibitors (ACEI), and 20 patients were taking one tablet of combined treatment (calcium blocker with ACEI).
Results: The percentage of patients with controlled ambulatory blood pressure was 0.86 among patients taking the drug at bedtime (P=0.005). Twenty-six patients with uncontrolled hypertension, receiving one drug or combined therapy at bedtime, showed a significant reduction in the 24-h mean systolic and diastolic blood pressure (6.2 and 2.6 mmHg, respectively; P<0.009). This reduction was more prominent during night-time (8.3 and 5.0 mmHg; P<0.001). In addition, all 26 patients showed normal blood pressure less than 140/90 during clinic measurement at daytime. Only four patients treated with monotherapy in the morning were unresponsive to the switching, and their blood pressure was controlled by the addition of a second drug at bedtime. The control group (who continued taking therapy in the morning) showed no reduction in blood pressure during night-time and remained with uncontrolled hypertension as they were at the beginning of the study.
Conclusion: In patients with uncontrolled hypertension, switching of therapy to bedtime should be considered to improve control and to avoid the nondipper pattern before any attempt is made to increase the dose or add more drugs. We need other research studies with long time follow-up to verify the efficacy of switching therapy.