Study: Prescribers Unaware of Comorbidity of Nonselective Beta Blockers for Patients With COPD or Asthma

A substantial number of prescribers did not regard nonselective beta blockers as contraindicated, suggesting the need for improvement programs that target the prescribers’ awareness and knowledge.

Previous recommendations in prevailing guidelines suggest avoiding the use of nonselective (NS) beta (β) blockers in patients with asthma or chronic obstructive pulmonary disease (COPD); however, on average 10 patients per community pharmacy receive these blockers monthly, according to researchers. A recent study found that a substantial number of prescribers were unaware of comorbidity or did not consider NS β-blockers contraindicated, despite the clinical guidelines.

The study involved 53 community pharmacists in the Netherlands who selected patients with actual concurrent use of inhalation medication and NS β-blockers. Each pharmacist screened all medication surveillance signals and actions taken at the first dispensing for at least 5 patients. Also, each pharmacist had selected 3 different initial prescribers for interviews that were intended to determine their awareness and their reasoning for using NS β-blockers.

“Due to the potential risk of triggering bronchoconstriction and an insufficient response to bronchodilator therapy during an exacerbation, use of non‐selective (NS) β‐blockers in patients with asthma or COPD is contraindicated according to prevailing guidelines for lung diseases and glaucoma,” explained the authors. “However, the contraindication in the guidelines is limited to NS β-blockers; fewer hospitalizations and emergency department visits occurred with cardioselective β-blockers, compared to NS β-blockers. There was no convincing evidence for a clinically relevant influence of selective β-blockers on bronchoconstriction.”

The pharmacists in the study identified 827 asthma/COPD patients who used NS β‐blockers. Of these patients, the researchers selected 153 NS β‐blockers to interview. The interviews revealed that 107 prescribers were aware of the drug-disease interaction of the asthma or COPD comorbidity when initiating the NS β‐blocker, while 46 prescribers were not. Furthermore, 40 prescribers did not consider the contraindication to be relevant when prescribing.

In addition, medication surveillance signals and actions at first dispensing were evaluated for 299 patients. Of those patients, 39.8% used ocular timolol, 30.8% used oral preparations propranolol, and 15.1% used carvedilol. The pharmacy system had generated a warning alert in 154 cases.

“Further research is needed to estimate whether NS β‐blockers may trigger the development of symptoms, whether this depends on different dose levels of NS β‐blockers or the duration of therapy, possible switching of dose levels in the past, or on specific co‐medication or co‐morbidities,” concluded the authors. “Evaluation of clinical outcomes is part of the implementation process, and this is an important topic for future research.”

Since a substantial number of prescribers were unaware of the comorbidity or did not regard NS β‐blockers as contraindicated, the researchers emphasize the need for improvement programs that target the prescribers’ awareness and knowledge of NS β‐blockers.

Reference

Kuipers E, Wensing M, De Smet PAGM, Teichert M. Considerations of prescribers and pharmacists for the use of non‐selective β‐blockers in asthma and COPD patients: an explorative study. J Eval Clin Pract. 2018;24(2):396-402. doi: 10.1111/jep.12869.