Which is less addicting, Flexeril (cyclobenzaprine) or Gabapentin?

Flexeril (Cyclobenzaprine) is Less Addicting than Gabapentin

Based on FDA labeling and systematic reviews, cyclobenzaprine has minimal to no addiction potential, while gabapentin carries documented risks of abuse, dependence, and withdrawal—particularly in patients with substance use disorder histories.

Key Differences in Addiction Risk

Cyclobenzaprine (Flexeril)

• The FDA label explicitly states that withdrawal symptoms after prolonged use are "not indicative of addiction" 1
• Pharmacologic similarities to tricyclic drugs may produce rare withdrawal symptoms (nausea, headache, malaise) upon abrupt cessation, but these do not represent true dependence 1
• There is concern that "some" skeletal muscle relaxants can lead to abuse and addiction, but cyclobenzaprine specifically lacks substantial evidence of addictive potential 2
• No documented cases of drug-seeking behavior or dose escalation for euphoric effects 1

Gabapentin

• The FDA acknowledges gabapentin abuse and dependence in postmarketing surveillance, particularly in patients taking higher-than-recommended doses for unapproved uses 3
• Most individuals misusing gabapentin had a history of polysubstance abuse or used it to relieve withdrawal symptoms from other substances 3
• Documented withdrawal symptoms include agitation, disorientation, and confusion after sudden discontinuation 3
• Systematic reviews identified 18 case reports/series of gabapentin addiction, with patients averaging >3000 mg/day (range 600-8000 mg/day) 4
• Misuse prevalence: 1.1% in general population but 22% in drug abuse treatment centers 4

Clinical Context and Risk Stratification

Population at Highest Risk for Gabapentin Addiction

• Patients with current or past substance use disorders (especially opioid and multi-drug users) represent the principal at-risk population 5, 6
• In patients without prior abuse history, only 4 cases of behavioral dependence meeting ICD-10 criteria have been documented 5, 6
• Gabapentin is increasingly sold on black markets and internet platforms 5, 7

Mechanism of Abuse Potential

• Gabapentin produces anxiolytic effects at therapeutic doses, stimulation at lower doses, and sedation with increasing doses 5
• Users report euphoria, though gabapentin's rewarding properties appear limited compared to traditional substances of abuse 6
• The drug may possess GABA-mimetic properties and possible effects on dopaminergic reward systems 7

Important Clinical Caveats

Around half of patients prescribed gabapentin continuously for ≥12 months—a practice not recommended by guidelines in many cases 2. This long-term prescribing pattern increases exposure to potential dependence risks.

When gabapentin is combined with opioids, dangerous respiratory depression can occur, and this combination is associated with overdose fatalities 2. This synergistic risk is particularly concerning given that opioid-dependent individuals frequently misuse gabapentin 5, 6.

Prescribing Recommendations

For patients without substance use disorder history:

• Both medications carry low addiction risk, but cyclobenzaprine has essentially negligible potential 1, 6
• Gabapentin requires standard monitoring without special addiction-focused precautions 3

For patients with current or past substance use disorders:

• Avoid gabapentin if possible 5, 6
• If gabapentin is indispensable, administer exclusively over limited time with strict therapeutic and prescription monitoring 5, 6
• Cyclobenzaprine remains the safer choice in this population 1

The FDA specifically recommends that prescribers "carefully evaluate patients for a history of drug abuse and observe them for signs and symptoms of gabapentin misuse or abuse (e.g., development of tolerance, self-dose escalation, and drug-seeking behavior)" 3.