Red flags on benzodiazepines, gabapentin in drug misuse report

Overall prescription drug misuse rates remain stable among general care patients undergoing medication monitoring, but newly released data from clinical lab results of Quest Diagnostics reveal some troubling trends for patients being treated for a substance use disorder.

Also, the information in this month's Quest Diagnostics report titled Health Trends: Drug Misuse in America 2018 sheds light on problems involving a drug and a drug category that are often on treatment professionals' radar: the anticonvulsant medication gabapentin and the benzodiazepine drug class. These results indicate:

• Among patients in general care from a healthcare provider, gabapentin was the only substance with an increase in use in non-prescribed form in the 2017 data.

• Concurrent use of opioids and benzodiazepines remains disappointingly common, despite well-publicized warnings to providers and patients about the serious health risks associated with using these drug classes together.

The report's findings are derived from an analysis of more than 3.9 million de-identified drug monitoring tests conducted by Quest Diagnostics nationwide. The analysis found that 52% of Quest's drug tests in 2017 showed signs of potential misuse, a percentage identical to the rate from 2016. These potentially problematic test results run the gamut from patients' supplementing their prescribed medication with another drug to patients' substituting other substances for the drug that was prescribed to them.

Leland McClure, MD, medical science liaison director at Quest, points out in an interview with Addiction Professional that while the prevalence of inconsistent results has dropped from a level of 63% in the study's first year of analysis in 2011, the fact that the rate has declined little since 2013 poses some concern. This is especially true in light of stepped-up drug monitoring efforts in much of the prescribing community, McClure says.

“We're seeing a plateauing effect on misuse,” he says.

Test inconsistency rates were found to be nearly identical between men and women, but were most common in the age groups between 18 and 44. Medicaid-insured individuals saw higher rates of test inconsistency than Medicare beneficiaries or the privately insured.

Gabapentin

McClure points out that rates of non-prescribed use of opioids and stimulants in the general care population declined from 2016 to 2017. Misuse of gabapentin, which is used medically to treat seizures and neuropathic pain, is rising, however.

Overall there was a slight increase in potential misuse of gabapentin in the Quest testing sample, but potential misuse surged from levels of the previous year among patients in substance use disorder treatment settings, the report found.

This becomes particularly problematic in light of evidence that gabapentin can exaggerate the effects of opioids. According to research published in the fall of 2017, “Individuals taking prescription opioids and gabapentin concomitantly have a 49% greater risk for opioid-related death than those treated with opioids only,” the report states.

While gabapentin was the only substance with an increase in non-prescribed use in the general care population, use of non-prescribed and illicit drugs in the substance use treatment cohort is seeing nearly across-the-board increases in the Quest Diagnostics data. “Most notably, the rates of non-prescribed fentanyl and heroin use in the [substance use disorder] center population increased nearly 400% in the past year,” the report states.

Benzodiazepines

Risk of respiratory suppression and cardiac distress associated with concurrent use of opioids and benzodiazepines remains an issue of concern despite advisories such as the Food and Drug Administration's (FDA's) boxed warning about the drugs' use in combination, a warning issued in 2016.

The Quest report states that more than one in five test results from monitored patients showed evidence of concurrent use of opioids and benzodiazepines in 2017. Moreover, in nearly two-thirds of these cases, at least one of the drugs was not prescribed.

For providers in specialty substance use treatment settings, “It is important to maintain diligence on use of combinations of medications,” says McClure.