title: Effect of aspirin on blood pressure in hypertensive patients taking enalapril or losartan.
abstract: The ability of angiotensin converting enzyme (ACE) inhibitors to lower blood pressure may in part be due to the formation of vasodilatory prostaglandins. Inhibition of prostaglandin synthesis with aspirin may therefore theoretically attenuate the antihypertensive effect of ACE inhibitors. This trial studied the interaction between aspirin (ASA) and enalapril, an ACE inhibitor, and ASA and losartan, an angiotensin subtype 1 receptor antagonist. Seventeen essential hypertensive patients were studied, maintained on a stable dose of either enalapril (n = 7) or losartan (n = 10) monotherapy for > or =12 weeks before and throughout the study. Each patient received a 2-week course of placebo, 81 mg/day ASA, and 325 mg/day ASA, each treatment separated by a 2-week washout period. Blood pressure (BP) and serum thromboxane B2 (TXB2) samples were obtained at the end of each treatment period. Placebo was compared with each dose of ASA for each group. In both the enalapril and losartan groups, mean, systolic, and diastolic BP were unchanged with the addition of ASA. Concentrations of TXB2 were suppressed to <10% in both groups with ASA. This study demonstrates that 81 to 325 mg/day ASA exerts no significant effect on BP in essential hypertensives taking enalapril or losartan.
authors.affiliation: Philadelphia College of Pharmacy, University of the Sciences in Philadelphia, Pennsylvania, USA. nawarska@unm.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Nawarskas
authors.forename: R R
authors.initials: RR
authors.lastname: Townsend
authors.forename: M D
authors.initials: MD
authors.lastname: Cirigliano
authors.forename: S A
authors.initials: SA
authors.lastname: Spinler
mesh_terms: D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001241:Aspirin / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004311:Double-Blind Method; D004347:Drug Interactions; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D019808:Losartan / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D016861:Cyclooxygenase Inhibitors; D013929:Thromboxane B2; D004656:Enalapril; D019808:Losartan; D001241:Aspirin