Q. One of the inclusion criteria state that the patient must have not used heroin in the past 3 months – however, there is no reference to any other recreational drug. Why? Does heroin have a unique effect on asthma pathology?


A. The goal of the study is to observe whether providing patients with asthma education and a corresponding Asthma Action Plan will reduce the number of ED visits due to asthma-related complications.

Heroin-users are likely excluded from the AAP study, simply due to the nature of heroin usage increasing the risk of ED visits and hospitalizations for asthma patients. Specifically, heroin is an acute respiratory depressant, meaning it leads to decreased or absent inspiratory airflow. In asthma patients, this can subsequently translate into severe asthma exacerbation, which is often life-threatening and requires intubation and ventilation. For several decades now, case reports, retrospective studies, and laboratory investigations have demonstrated this connection between heroin usage and reduced pulmonary function and the subsequent increase in emergency department visits and hospitalizations for asthma.

In order words, heroin users are likely excluded from our study because even if a user embraced the AAP – took both controller and reliever medications and knew exactly what actions to take given their peak flow at a given moment – there is a high chance the user would still return to the ED frequently for heroin-induced asthma-related complications, thereby reducing our ability to determine the efficacy of the asthma action plan (ie. the statistical power of the study).

Follow-up Q: What I do wonder still, however, is why we are not also excluding cocaine users, as cocaine has been shown to exert similar effects on asthmatic individuals. Any thoughts?



  1. Understanding Heroin Overdose: A Study of the Acute Respiratory Depressant Effects of Injected Pharmaceutical Heroin (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4619694)
  2. Asthma associated with the use of cocaine, heroin, and marijuana: A review of the evidence (https://www.ncbi.nlm.nih.gov/pubmed/27858495)