Alcohol and Flexeril (Cyclobenzaprine): Not Recommended
No, patients should not drink alcohol while taking Flexeril (cyclobenzaprine), as the FDA explicitly warns that cyclobenzaprine may enhance the effects of alcohol and other CNS depressants, potentially impairing mental and physical abilities required for safe functioning. 1
FDA-Mandated Warning
The official FDA drug label for cyclobenzaprine clearly states that:
- Cyclobenzaprine enhances the effects of alcohol, barbiturates, and other CNS depressants 1
- The combination may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle 1
- Patients should be specifically counseled about this interaction during medication initiation 1
Clinical Risks of Combined Use
Central Nervous System Depression
The combination of cyclobenzaprine and alcohol produces additive CNS depressant effects through a pharmacodynamic interaction, where alcohol enhances the sedating effects of the medication 2. This can result in:
- Excessive sedation and drowsiness beyond what either substance produces alone 2
- Impaired coordination and judgment, increasing fall risk 2
- Respiratory depression in severe cases 2
Documented Fatal Case
A forensic case report documented a fatal drowning in a 35-year-old woman with blood alcohol of 215 mg/dL and cyclobenzaprine level of 1.786 mg/L, demonstrating that this combination can have lethal consequences 3. While this involved high levels of both substances, it illustrates the serious potential for harm.
Real-World Adverse Events
In mental health patients taking psychotropic medications (which share similar CNS depressant properties with cyclobenzaprine), 23% reported serious adverse effects from alcohol-drug interactions, including worsening psychiatric conditions, hospital admissions, and increased drowsiness 4. This suggests patients frequently underestimate these risks despite receiving counseling.
Practical Clinical Guidance
What to Tell Patients
Advise patients to:
- Completely avoid alcohol while taking cyclobenzaprine 1
- Understand that even moderate alcohol consumption can cause dangerous sedation 2
- Be aware that the risk extends to all forms of alcohol, including beer, wine, and spirits 2
- Know that this interaction can impair driving ability and increase fall risk 1
Special Populations at Higher Risk
Elderly patients face compounded risks because:
- Cyclobenzaprine plasma concentrations are already elevated in this population 1
- They have increased susceptibility to CNS adverse events including hallucinations and confusion 1
- Falls and their sequelae pose greater morbidity and mortality risks 1
Patients with hepatic impairment should exercise extreme caution as:
- Cyclobenzaprine concentrations are increased with liver dysfunction 1
- These patients are more susceptible to sedating effects 1
- Alcohol itself causes hepatic stress 5
Common Clinical Pitfall
Many patients report receiving advice to avoid alcohol but do not follow this guidance 4. The gap between counseling and compliance is substantial—in one study, 75% received counseling but only 49% followed the advice 4. This emphasizes the need for:
- Clear, direct warnings about specific risks (sedation, falls, impaired driving)
- Written information provided at prescription
- Reinforcement at follow-up visits about the ongoing contraindication
Duration of Restriction
The alcohol restriction applies throughout the entire treatment course with cyclobenzaprine 1. Since muscle relaxants should only be used short-term (trials were ≤2 weeks duration), this represents a time-limited but absolute restriction 6.