Manufacturers warn that patients who are hypersensitive to any component of carvedilol should not take it.1-4 They also caution that carvedilol might worsen severe allergic reactions and reduce the effectiveness of medicines used to treat them. Patients who have had a severe anaphylactic reaction in the past should be aware that taking carvedilol may make them less responsive to normal doses of epinephrine, medications commonly used to treat anaphylaxis.5 Carvedilol2 and carvedilol phosphate3 are active ingredients of carvedilol immediate-release tablets and extended-release capsules, respectively.
Studies and reviews observing adverse reactions of beta blockers report no increase in cases of anaphylactic allergic reactions or any serious adverse reactions related to allergic reactions.6-8 A systematic review of beta blocker side effects included 13 randomized controlled trials with 7,836 patients in the beta blocker arm.7 The study listed 33 side effects, of which anaphylactic allergic reaction was not listed as one. However, anaphylactic allergic reactions may not have been specifically assessed for, and the duration of follow-up in these studies was variable.
A case-control analysis examined the incidence rates of severe hypersensitivity reactions for various beta blockers among a cohort of beta blocker users in the LabRx Database.9 The study defined incident hypersensitivity reaction as a reaction of either anaphylactic shock or angioneurotic edema. Among 1.8 million beta blocker users, 7,914 events of severe hypersensitivity reactions were found. The unadjusted incidence rate was 2.40 events per 1,000 person-years (95% confidence interval [2.35 – 2.45]).
References
- Auro-Carvedilol [package insert]. Ontario, CA: Aurobindo Pharma Inc.; 2013.
- Coreg [package insert]. Ciales, PR: GK Pharmaceuticals Contract Manufacturing Operations; 2008.
- Coreg CR [package insert]. Ciales, PR: GK Pharmaceuticals Contract Manufacturing Operations; 2008.
- APO-Carvedilol [package insert]. Toronto, Canada: Apotex Pharmaceutical Holdings Inc.; 2015.
- Kemp SF, Lockey RF, Simons FE. Epinephrine: the drug of choice for anaphylaxis-a statement of the world allergy organization. World Allergy Organ J. 2008;1(7 Suppl):S18-26.
- Krum H, Roecker EB, Mohacsi P, et al. Effects of initiating carvedilol in patients with severe chronic heart failure: Results from the copernicus study. JAMA. 2003;289(6):712-718.
- Barron AJ, Zaman N, Cole GD, Wensel R, Okonko DO, Francis DP. Systematic review of genuine versus spurious side-effects of beta-blockers in heart failure using placebo control: Recommendations for patient information. Int J Cardiol. 2013;168(4):3572-3579.
- Ko DT, Hebert PR, Coffey CS, et al. Adverse effects of beta-blocker therapy for patients with heart failure: a quantitative overview of randomized trials. Arch Intern Med. 2004;164(13):1389-1394.
- Koro CE, Sowell MD, Stender M. An assessment of the association between carvedilol exposure and severe hypersensitivity reactions, angioedema, and anaphylactic reactions: a retrospective nested case-control analysis. Clin Ther. 2012;34(4):870-877.
