ADDITIVE EFFECTS OF CAPTOPRIL AND LOSARTAN ON BLOOD-PRESSURE IN MILDLY SODIUM-DEPLETED NORMOTENSIVES

The lowering of the mean blood pressure (MBP) by a combination of losa rtan 50mg/captopril 50mg and by, respectively, losartan 50mg and 100mg and captopril 50mg and 100mg was studied in 10 sodium-depleted normal subjects. A double-blind, randomised, 5-way crossover study design wa s followed. To induce the mild sodium depletion, each subject took 40m g furosemide orally 12 hours preceding each study session. On each stu dy day the subjects were placed in a semirecumbent position and the MB P and heart rate were monitored at defined intervals over the 8 hours following the administration of the antihypertensive drug. The differe nce between captopril 100mg and the combination regimens did not reach statistical significance. The combination of losartan 50mg/captopril 50mg caused a significantly greater maximum baseline-subtracted fall i n MBP at 2 hours than did the 50 or 100mg losartan at 6 hours (p < 0.0 5). In addition, the area under the concentration time curve from 1 to 8 hours (AUC(1-8)) for the fall in MBP with the combination was signi ficantly larger than that with the losartan-only regimens. In conclusi on, it appears that the administration of the combination of an ACE in hibitor and angiotensin II antagonist provides a more pronounced lower ing of MBP than equivalent increases in the dose of one drug or the ot her, at least when administered short term to sodium-depleted normal s ubjects.