Angiotensin II receptor antagonist
Angiotensin II receptor antagonists, also called Angiotensin II Type 1 receptor blockers ('ARBs) are "agents that antagonize angiotensin II type 1 receptor. Included are angiotensin II analogs such as saralasin and biphenylimidazoles such as losartan. Some are used as antihypertensive agents."[1]
Inhibition of the renin-angiotensin system is used to treat hypertension, heart failure, and chronic kidney disease.
Mechanism of action
Angiotensin II receptor antagonists block angiotensin II AT1 receptors, in contrast to angiotensin-converting enzyme inhibitors, which block the conversion of angiotensin I to the hypertensive angiotensin II. Along with Angiotensin-converting enzyme inhibitors. Randomized controlled trials have investigated the use of the two classes together for a synergistic effect, but have found increased adverse effects with no added benefit from their combination.[2]
Applications
These drugs are primarily antihypertensives. A meta-analysis by the Cochrane Collaboration concluded:[3]
- The blood pressure "lowering effect of ARBs is modest and similar to ACE inhibitors as a class; the magnitude of average trough BP lowering for ARBs at maximum recommended doses and above is -8/-5 mmHg. Furthermore, 60 to 70% of this trough BP lowering effect occurs with recommended starting doses."
- "There are no clinically meaningful BP lowering differences between available ARBs."
ARBs may also be used to protect the kidneys.
Adverse effects
Hyperkalemia
Angiotensin II receptor antagonists can cause hyperkalemia. The rise in potassium has been reported to be both similar to[4] and less that occurs with angiotensin-converting enzyme inhibitors.[5] A newer factorial randomized controlled trial has compared these drugs.[6]
Angioedema
Patients who previously had angioedema (a hypersensitivity reaction) with angiotensin-converting enzyme inhibitors may be at increased risk of angioedema with angiotensin II receptor antagonists.[7]
References
- ↑ Anonymous (2024), Angiotensin II Type 1 Receptor Blockers (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ McMurray JJ (April 2008). "ACE inhibitors in cardiovascular disease--unbeatable?". N. Engl. J. Med. 358 (15): 1615–6. DOI:10.1056/NEJMe0801925. PMID 18378521. Research Blogging.
- ↑ Heran BS, Wong MM, Heran IK, Wright JM (2008). "Blood pressure lowering efficacy of angiotensin receptor blockers for primary hypertension". Cochrane database of systematic reviews (Online) (4): CD003822. DOI:10.1002/14651858.CD003822.pub2. PMID 18843650. Research Blogging.
- ↑ The ONTARGET Investigators. 2008. Telmisartan, Ramipril, or Both in Patients at High Risk for Vascular Events. N Engl J Med 358, no. 15:1547-1559.
- ↑ Bakris GL, Siomos M, Richardson D, et al (2000). "ACE inhibition or angiotensin receptor blockade: impact on potassium in renal failure. VAL-K Study Group". Kidney Int. 58 (5): 2084–92. DOI:10.1111/j.1523-1755.2000.00381.x. PMID 11044229. Research Blogging.
- ↑ Mann et al. 2008. Lancet. Renal outcomes with telmisartan, ramipril, or both, in people at high vascular risk (the ONTARGET study): a multicentre, randomised, double-blind, controlled trial
- ↑ Haymore BR, Yoon J, Mikita CP, et al. Risk of angioedema with angiotensin receptor blockers in patients with prior angioedema associated with angiotensin-converting enzyme inhibitors: a meta-analysis. Ann Allergy Asthma Immunol. 2008 November;101:495-9.