Efficacy of Blood Pressure reduction of Losartan in selected Thai populations using Home Blood Pressure Monitoring and Office Blood Pressure measurements.

Background: Angiotensin Receptor Blockades (ARB) is becoming a first line drug for essential Hypertension for many types of patient. Losartan is the prototype of ARB due to its vast clinical trials. Home Blood pressure monitoring can provide accurate evaluation of certain drug effect on blood pressure with small number of patient samples. Local production of medicine has made the Medicine readily available and could bring about clinical improvement. Our hypothesis was that Thai population with essential hypertension responded quite well to Losartan and Generic Losartan was not inferior to Original- Losartan.

Objective: To evaluate the effectiveness and safety in BP reduction by Losartan in certain Thai population and to compare these parameters between Generic Losartan and Original-Losartan using both office and HBPM method.

Method: After a two-week run-in period when they would learn to use HBPM device and their blood pressure were still recorded to be higher than 140/90 by office BP or 135/85 by HBPM with or without previous medical regimen, 24 patients were randomized to receive either Generic Losartan or Original-Losartan for 6 weeks. Then they would cross over to receive the alternative and were followed again at 6 weeks. HBPM was performed in the morning and in the evening for 5 days, at baseline, and after 6 & 12 weeks. Office BP measurements were obtained at baseline and after 6 & 12 weeks.

Result: One patient in each group dropped out from the study. 22 patients with average age of 54 and averaged office BP 154/88 completed the 12 weeks study. By office BP, SBP was reduced by 27±14.2 at week 6 and 28±15.1 mmHg at week 12. By HBPM, SBP dropped by 17±10.8 at week 6 and by 18±9. at week12. At the end of 12 weeks 68% (15/22) of patients had Office BP <140/90 and 64% (14/22) of patients had HBPM <135/85. There was no significant difference of BP reduction at week 6 between Original-xLosartan and Generic Losartan group. After crossover the BP reduction was maintained in both groups. The percentage of patient whose Office BP <140/90 or HBPM <135/85 were not different among the two Losartan groups. There was no serious adverse side effect.

Conclusion: Using both office BP and HBPM this group of Thai patient with essential hypertension responded well to Losartan and Generic Losartan.