Background: Rilmenidine is an antihypertensive agent that selectively binds to imidazoline I1 receptor located in the brainstem and kidney. It acts both centrally by reducing sympathetic overactivity and in the kidney by decreasing water and sodium overload. This dual action leads to the immediate and delayed control of blood pressure caused by this drug.
Objective: The aim of this study was to assess the efficacy and safety of rilmenidine as monotherapy in mild-to-moderate essential hypertensive patients.
Method: An 8-week, open-labeled, multicenter study was conducted in Thai patients with mild-to-moderate essential hypertension. Rilmenidine 1 mg/day was given for 8 weeks. The dose could be titrated up to 2 mg/day according to the patient's blood pressure response at week 4. The primary efficacy parameters were the mean reductions in systolic and diastolic blood pressure. The proportions of patients whose blood pressure normalized or responded were evaluated as secondary efficacy parameters. Safety parameters were assessed by the changes in heart rate and reported side effects during the treatment period.
Results: 103 subjects (44.7% men) with a mean age of 53 +/- 9.7 years completed the 8-week follow-up. At baseline, 46.6 per cent and 53.4 per cent of the patients were classified with mild and moderate hypertension, respectively. The mean blood pressure was 154/93 mmHg. After the 8-week treatment, there was a significant decrease in blood pressure to 140/86 mmHg (p < 0.001), with mean pressure reduction of 14/7.5 mmHg. The normalization rate was 44 per cent and the response rate was 68 per cent. No significant changes were found for mean heart rate and any laboratory parameters tested. Only 17 patients reported mild and transient side effects such as drowsiness and dryness of the mouth and throat, which required no treatment.
Conclusion: This study has shown that rilmenidine is an effective and well tolerated monotherapy in Thai patients with mild-to-moderate essential hypertension.