Blood pressure medications have similar results but different side effects

When comparing first-time prescriptions of a single medication for high blood pressure, angiotensin-converting enzyme, or ACE, inhibitors are as effective as angiotensin receptor blockers, or ARBs, in the prevention of cardiovascular events, new research has found. The similarities, however, end with efficacy. The results are published in Hypertension.

In a U.S. National Science Foundation-supported study that analyzed data from almost 3 million patients, the side effects and safety concerns of these medications were noted and examined. The results showed that patients taking ARBs were less likely to experience serious side effects when compared to patients prescribed ACE inhibitors. To date, ACE inhibitors are more commonly prescribed. The findings from this research will help doctors tailor blood pressure medications to more closely meet the needs of patients.

Patients taking ACE inhibitors were more likely to develop cough, pancreatic inflammation, gastrointestinal bleeding and fluid accumulation. However, these findings do not include patients taking multiple medications or those already taking ACE inhibitors. 

Both medications target the renin-angiotensin-aldosterone system, a group of hormones that act as blood pressure regulators, and block angiotensin to reduce blood vessel constriction. ACE inhibitors lower blood pressure by blocking an enzyme so less angiotensin is produced, and ARBs block the blood vessel receptors to which angiotensin attaches.

Results from this analysis of first-time therapy may not translate to patients prescribed combination treatments or who switch regimens. Patients in the study were observed over varying durations of time, and some participants had shortened follow-up periods which could result in less therapeutic effectiveness.

"This team developed a comprehensive framework for real-world evidence to predict drug efficacy and safety while minimizing bias," says Sylvia Spengler, a program director in NSF's Directorate for Computer and Information Science and Engineering, which partially supported the research.