The antihypertensive effect of a single dose persisted for 24 hours. In most trials, the antihypertensive effect of fosinopril sodium increased during the first several weeks of repeated measurements. The antihypertensive effect of fosinopril sodium has been shown to continue during long-term therapy for at least 2 years. Abrupt withdrawal of fosinopril sodium has not resulted in a rapid increase in blood pressure. Limited experience in controlled and uncontrolled trials combining fosinopril with a calcium channel blocker or a loop diuretic has indicated no unusual drug-drug interactions.
ACE inhibitors are generally less effective in blacks than in non-blacks.
The effectiveness of fosinopril sodium was not influenced by age, sex, or weight. Reduction in systemic blood pressure appears to have been mediated by a decrease in peripheral vascular resistance without reflex cardiac effects. Similarly, renal, splanchnic, cerebral, and skeletal muscle blood flow were unchanged compared to baseline, as was glomerular filtration rate. No tachyphylaxis was seen. Favorable effects were maintained for up to two years.