Reviews

Gabapentin for alcohol use disorder: A good option, or cause for concern?

Author and Disclosure Information

 

References

POTENTIAL FOR MISUSE

The use of gabapentin has become controversial owing to the growing recognition that it may not be as benign as initially thought.7–9,34 A review of US legislative actions reflects concerns about its misuse.35 In July 2017, Kentucky classified it as a schedule V controlled substance with prescription drug monitoring,35 as did Tennessee in 201836 and Michigan in January 2019.37 Currently, 8 other states (Massachusetts, Minnesota, Nebraska, North Dakota, Ohio, Virginia, Wyoming, and West Virginia) require prescription drug monitoring of gabapentin, and other states are considering it.35

Efforts to understand gabapentin misuse derive largely from people with drug use disorders. A review of postmortem toxicology reports in fatal drug overdoses found gabapentin present in 22%.38 Although it was not necessarily a cause of death, its high rate of detection suggests wide misuse among drug users.

Among a cohort of 503 prescription opioid misusers in Appalachian Kentucky, 15% reported using gabapentin “to get high.” Those who reported misusing gabapentin were 6 times more likely than nonusers to be abusing opioids and benzodiazepines. The main sources of gabapentin were doctors (52%) and dealers (36%). The average cost of gabapentin on the street was less than $1.00 per pill.39

Gabapentin misuse by methadone clinic patients is also reported. Baird et al40 surveyed patients in 6 addiction clinics in the United Kingdom for gabapentin and pregabalin abuse and found that 22% disclosed misusing these medications. Of these, 38% said they did so to enhance the methadone high.

In a review article, Quintero41 also cited enhancement of methadone euphoria and treatment of opioid withdrawal as motivations for misuse. Opioid-dependent gabapentin misusers consumed doses of gabapentin 3 to 20 times higher than clinically recommended and in combination with multiple drugs.4 Such use can cause dissociative and psychedelic effects.

Gabapentin also potentiates the sedative effects of opioids, thus increasing the risk of falls, accidents, and other adverse events.34,35 Risk of opioid-related deaths was increased with coprescription of gabapentin and with moderate to high gabapentin doses.34

Are people with AUD at higher risk of gabapentin abuse?

Despite concerns, patients in clinical trials of gabapentin treatment for AUD were not identified as at high risk for misuse of the drug.2,4,5,16 Further, no such trials reported serious drug-related adverse events resulting in gabapentin discontinuation or side effects that differed from placebo in frequency or severity.2,4,5,16

Clinical laboratory studies also have found no significant interactions between alcohol and gabapentin.42,43 In fact, they showed no influence of gabapentin on the pharmacokinetics of alcohol or on alcohol’s subjective effects. Relative to placebo, gabapentin did not affect blood alcohol levels, the degree of intoxication, sedation, craving, or alcohol self-administration.

Smith et al9 reported estimates that only 1% of the general population misuse gabapentin. Another review concluded that gabapentin is seldom a drug of choice.17 Most patients prescribed gabapentin do not experience cravings or loss of control, which are hallmarks of addiction. Hence, with adequate precautions, the off-label use of gabapentin for AUD is reasonable.

CLINICAL IMPLICATIONS OF GABAPENTIN PRESCRIBING

Overall, evidence for the benefit of gabapentin in AUD is mixed. Subgroups of alcoholic patients, such as those who do not respond to or tolerate standard therapies, may particularly benefit, as may those with comorbid insomnia or neuropathic pain.44 Clinicians should prescribe gabapentin only when it is likely to be helpful and should carefully document its efficacy.2,45

At each visit, an open and honest assessment of the benefits and risks serves to promote shared decision-making regarding initiating, continuing, or discontinuing gabapentin.

For alcohol withdrawal

Before gabapentin is prescribed for alcohol withdrawal, potential benefits (reduction of withdrawal symptoms), side effects (sedation, fatigue), and risks (falls) should be discussed with the patient.46 Patients should also be informed that benzodiazepines are the gold standard for alcohol withdrawal and that gabapentin is not effective for severe withdrawal.46

For relapse prevention

When initiating treatment for relapse prevention, the patient and the prescriber should agree on specific goals (eg, reduction of drinking, anxiety, and insomnia).2,16 Ongoing monitoring is essential and includes assessing and documenting improvement with respect to these goals.

In the AUD studies, gabapentin was well tolerated.16 Frequently observed side effects including headache, insomnia, fatigue, muscle aches, and gastrointestinal distress did not occur at a statistically different rate from placebo. However, patients in studies are selected samples, and their experience may not be generalizable to clinical practice. Thus, it is necessary to exercise caution and check for comorbidities that may put patients at risk of complications.47 Older patients and those on hemodialysis are more susceptible to gabapentin side effects such as sedation, dizziness, ataxia, and mental status changes,34 and prescribers should be alert for signs of toxicity (eg, ataxia, mental status changes).47,48

Gabapentin misuse was not observed in AUD studies,2,4,5,16 but evidence indicates that patients with opioid use disorder, prisoners, and polydrug users are at high risk for gabapentin misuse.39–41 In all cases, clinicians should monitor for red flags that may indicate abuse, such as missed appointments, early refill requests, demands for increased dosage, and simultaneous opiate and benzodiazepine use.49

Acknowledgment: The authors wish to thank Nick Mulligan for his invaluable assistance with formatting and grammar.

Next Article:

Off-label and oft-prescribed

Related Articles

  • Current Drug Therapy

    Drug adjuncts for treating alcohol dependence

    We have learned much about the neurochemical basis of alcohol dependence over the past 20 years, but we still have only a few drugs for treating...

  • From the Editor

    Off-label and oft-prescribed

    When prescribing drugs for uses beyond their FDA indications, we need to explain their anticipated side effects and benefits.