ER vs. IR Drugs: An Interview with Theresa Cassidy, VP of Health Analytics

Inflexxion’s Vice President of Health Analytics, Theresa Cassidy, was recently interviewed on the issues and abuse of Extended Release (ER) opioids vs. Immediate Release (IR) opioids based on supporting data and analytics.

Q1: Extended Release opioids have more stringent regulatory restrictions because of their potential for tampering/abuse. The focus on extended-release/long acting opioids as a class wide Risk Evaluation and Mitigation Strategy is an example of this. How widely do you think IR opioids are being abused? Can you share any data to support this?

A1: Abuse of Immediate-release (IR) opioids is certainly a public health concern. They impact a broad segment of the adult and adolescent population and are the most widely prescribed pain medications in the country at a population level.  We have found that IR opioids like hydrocodone and oxycodone combination products have higher abuse prevalence (nearly 2 to 3 times more) compared to ER opioids among adults and adolescents with substance abuse problems.

Abuse of immediate-release and extended-release opioid product for adults within substance abuse treatment (July 2015 – June 2016)

Source: data from ASI-MV, NAVIPPRO

Q2: Based on your data, can you talk about whether the 2014 reclassification of Hydrocodone IR from a class III to a class II substance had a measurable impact on abuse rates?

A2: This is an interesting and important question and is related to the how the total amount of prescriptions impacts abuse.  We know that there is a relationship or correlation between the abuse level for a product and the amount of product available that can be diverted for misuse or abuse.  It stands to reason that if the total amount of drug available is reduced that there should be a corresponding reduction in abuse.  What is not well understood is how much of a reduction in total prescriptions is necessary to observe a meaningful change in abuse-related events.  The amount of prescriptions dispensed for hydrocodone/acetaminophen dropped from 125 million in 2014 to 90 million 2015 after the rescheduling but this still represented the majority of prescriptions dispensed for all opioids (62% of all prescriptions dispensed).

Q3: Is the problem compounded with IR drugs that are also generic?

A3: The large majority of IR products are generic formulations (92%).Combined with the fact that IRs are not part of the class wide REMS, there is minimal guidance on this drug grouping and how to measure abuse. Additionally, the majority of hydrocodone and oxycodone medications are generic (98%), and these are two of the most widely abused drugs on the market.

Q4: Can you share some studies you’ve undertaken that address this topic?

A4: Yes:  We’ve done some studies recently to better understand the progression of non-medical use of hydrocodone combination products and how that relates to abuse of other prescription opioids and illicit drugs and associated problems. Among a recent sample of recreational drug abusers, we found that approximately 63% reported first non-medical use of HCPs between the ages of 10 and 18.  Nearly 50% believed initial use of HCPs led them to abuse other prescription opioids with those who began using these products at young ages to report subsequent snorting or injecting of other prescription opioids.  These findings suggest that initial abuse exposures to these types of products during adolescence can lead to abuse of more potent opioids and more dangerous routes of administration (Cassidy et al., 2016. Progression of non-medical use of hydrocodone combination products: results from an Internet survey of recreational drug users.  Poster presentation. International Conference on Opioids (ICOO), June 5-7, 2016, Boston, MA).

Q5: What do you see as an important focus to help understand issues with ER and IR abuse?

A5: I think an important aspect of understanding abuse of IR versus ER opioid products will be effective monitoring and measuring abuse outcomes for these products, particularly new formulations or abuse deterrent formulations (ADFs) for IR products. Since the IR opioid market is largely generic products, this presents a challenge to design studies that can monitor and measure abuse of new products with low market share.  In addition, to traditional surveillance systems, other data sources such as monitoring of drug discussion may become important sources of information regarding abuse of these products.