[High doses of aspirin reduce natriuresis in hypertensive patients treated with enalapril].

Angiotensin converting enzyme inhibitors have been shown to be useful in the treatment of essential hypertension while anti-platelet agents improve the overall cardiovascular risk profile in this population. Our aim was to assess the interaction of two different aspirin (ASA) doses--81 and 325 mg/day--with the antihypertensive effect of enalapril as well as their impact upon the urinary sodium excretion (Na(u)). A total of 22 patients between 35 and 65 years of age were included in a prospective double blind trial with a partial cross-over design. We excluded patients with secondary hypertension and recent use of anti-inflammatory drugs. Patients were placed on enalapril and a low sodium diet--<6 g of NaCl/day--and, sequentially, on two different doses of aspirin separated by a 10 day wash out period. Blood pressure (BP) was measured at weekly visits. Systolic, diastolic and mean BP levels decreased significantly in enalapril-treated patients (p<0.01) and no difference was detected between the two AAS dosages although a non-statistically significant difference towards better BP control was observed when 81 mg of ASA was used. Na(u) was higher at baseline when compared with the two periods under ASA (p<0.01) and Na(u) was higher with 81 mg than with 325 mg. These results suggest that in essential hypertensive individuals treated with enalapril and two ASA doses, low doses of ASA are associated with better blood pressure control and higher natriuresis.