Accuracy of Side Effect Reporting in Australian Prescribing Information

Abstract

The beneficial effects observed in patients taking inert substances placebo effects are well known. Less recognised are the adverse effects from these inert substances - the nocebo effect. Patients, perceptions strongly influence nocebo effects; thus to distinguish true adverse effects from nocebo effects requires blinding [[1]Planès S. Villier C. Mallaret M. The nocebo effect of drugs.Pharmacology Research & Perspectives. 2016; 4Google Scholar]. Although beta-blockers have proven efficacy in heart failure, use may be limited by concerns about side effect. Side effect information in Australian prescribing information may overestimate the true rate of side effects and limit usage of these life-preserving heart failure medications. We compared the adverse effects listed in a systematic review of randomised control trials of beta-blockers with the adverse effects listed in reference texts: The Australian Medicines Handbook Online and MIMS Online [2Barron A.J. Zaman N. Cole G.D. Wensel R. Okonko D.O. Francis D.P. Systematic review of genuine versus spurious side-effects of beta-blockers in heart failure using placebo control: recommendations for patient information.International journal of cardiology. 2013; 168: 3572-3579Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar, 3Australian Medicines Handbook. Adelaide: Australian Medicines Handbook Pty Ltd; 2019. January. Available from http://amhonline.net.au.Google Scholar, 4Metoprolol. In. MIMS Online. St Leonards, Australia; MIMS Australia. Available from http://www.mimsonline.com.au.Google Scholar]. 25 of 33 adverse effects listed in the systematic review were listed in AMH or MIMS. Of all listed adverse effects the rates were comparable for 10/25. Adverse effects were overestimated in 15/25 cases. Twelve adverse effects listed as common in reference texts were actually less common in the active treatment arm of randomised control trials. This study demonstrates that Australian reference texts overestimate the true rate of adverse effects attributable to beta-blockers and misinform patients and clinicians. As recognised by Barron et al. [[2]Barron A.J. Zaman N. Cole G.D. Wensel R. Okonko D.O. Francis D.P. Systematic review of genuine versus spurious side-effects of beta-blockers in heart failure using placebo control: recommendations for patient information.International journal of cardiology. 2013; 168: 3572-3579Abstract Full Text Full Text PDF PubMed Scopus (74) Google Scholar] overestimating these adverse effects may lead to clinicians and patients ceasing beneficial medications. Reviewing how information on adverse effects is published in Australian prescribing references may improve treatment of many conditions and reduce discontinuation of proven therapies.