Monday, January 12, 2015

Renin-angiotensin system inhibitors versus other types of medicine for hypertension

Cochrane: Hypertension is a long-lasting medical condition in which a person's blood pressure is high. Hypertension can contribute to other health problems such as heart disease, stroke, and kidney problems, and so reduces quality of life.


What medicines can be used to treat hypertension?
 
There are a number of types of medicines that can be used to treat hypertension. These include three types of renin-angiotensin system (RAS) inhibitors: angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors. Other types of medicine include thiazide diuretics, beta-blockers, and calcium channel blockers (CCBs).
The first medicine that a person is prescribed for treating hypertension is called the 'first-line' medicine. Frequently, over time, other medicines are added to this in an attempt to reduce blood pressure in the long-term.

The purpose of this research
 
Researchers from the Cochrane Collaboration tried to determine how RAS inhibitors compare as first-line medicines for treating hypertension with other types of first-line medicines (thiazide diuretics, beta-blockers, CCBs, alpha-blockers, or central nervous system (CNS) active drugs) for hypertension.

What this research discovered
 
The researchers searched the medical literature up to November 2014 to identify all the relevant medical research. They identified a total of 42 medical studies that had included a total of 65,733 participants, with an average age of 66 years.
Nine of these studies did not include people who had suffered heart attacks or strokes, but 14 studies did include them if the heart attack or stroke had happened more than three or six months before the study began. Twelve studies included diabetic participants, and seven included people with kidney problems.
Twenty-six of the 42 studies were sponsored by pharmaceutical companies that manufactured the medicines being studied. The researchers did not investigate how this might have affected the results.
The results of the research showed moderate quality evidence that:
1. thiazides caused less heart failure and stroke than RAS inhibitors;
2. RAS inhibitors caused less heart failure but more stroke than CCBs, however the reduction in heart failure was considerably bigger than the increase in stroke.
Less robust results showed that RAS inhibitors reduced heart attacks and stroke compared to beta-blockers.
The different medicines produced small differences in effect on blood pressure, but these did not seem to be related to the number of heart attacks, strokes and kidney problems.
More trials are needed to strengthen the findings of this review.
- See more at: http://summaries.cochrane.org/CD008170/HTN_renin-angiotensin-system-inhibitors-versus-other-types-of-medicine-for-hypertension#sthash.GTaxPl8T.dpuf