As cases of misuse rise, be diligent when filling gabapentin prescriptions

Toxicologists, health care practitioners, and others are noticing an alarming trend as physicians have begun prescribing fewer opioids: Gabapentin prescriptions and subsequent misuse of the painkiller have increased.

While diversion and misuse of gabapentin is well documented, a research team set out to quantify how widespread the problem really is. Using a complete database of gabapentin cases reported to poison control centers nationwide between 2013 and 2017, the researchers found that exposures to the drug increased 72% during the 5-year study period. They published their results in the journal Clinical Toxicology.

Gabapentin is recognized as a first-line agent for treatment of neuropathic pain, and many health care providers have embraced it as a safer alternative to opioids for pain management. DEA has not classified it as a controlled substance, but some individual states have made gabapentin a Schedule V controlled substance.

“This means that it has a lower potential for abuse than the other controlled substances, but that risk is still there,” said Katie Tellor, PharmD, FACC, BCPS, an associate professor at St. Louis College of Pharmacy.

Around the same time the study was published, FDA issued a warning discussing the risks of misuse and toxicity of gabapentin, particularly in combination with opioids. In a safety communication, FDA warned about breathing difficulties for patients who have respiratory risk factors and asked that new warnings be added to the prescribing information of gabapentinoids.

In addition to gabapentin exposures, the research team also analyzed baclofen exposures from 2014 through 2017 and saw an increase of 36% in misuse attempts.

“The misuse of baclofen is less prevalent and less well described; however, it has been apparent in my clinical practice, as has serious illness related to both acute toxicity and withdrawal, which is consistent with our findings,” said lead study author Michael Lynch, MD, medical director of the Pittsburgh Poison Center.

Lynch said the upward trend in overall exposures and misuse for both drugs confirmed their hypothesis.

“However, the magnitude of exposures related to suicide attempts was jarring and really underscores the co-occurrence of pain and mood disorders as well as the importance of screening for and addressing depression and suicidal thoughts,” he said.

According to the study findings, suspected suicide attempts involving gabapentin increased by 81% nationwide over the study period.

Another notable finding was an increase in health care utilization and expense associated with hospital and ICU admissions following exposures to each drug, but especially baclofen. 

When taken in high doses, gabapentin can give users the similar dissociative effects seen with other drugs that have a net effect on dopamine and downstream euphoria, said Jeffrey Fudin, PharmD, adjunct associate professor at Albany College of Pharmacy and Health Sciences in New York.

“Various reports have outlined that high doses of gabapentin and increased quantities are more prevalent now compared with several years ago, and community pharmacists have reported instances of early refills and overtaking gabapentinoids beyond prescribed doses and at shortened intervals,” he added.

Fudin advised pharmacists to be particularly diligent when filling prescriptions for gabapentin. They should approach each prescription as if it were a scheduled drug in their state, even if it’s not, he said.

For the full article, please visit www.pharmacytoday.org for the March 2020 issue of Pharmacy Today.