Flexeril (Cyclobenzaprine) Usage – Dosage – Side Effects – Getting High – And With Alcohol

Dr. April Harris DO

This article was reviewed and approved by Dr. April Harris DO
Written by Drew Davis

This article is about Flexeril (cyclobenzaprine), its dosages, side effects, getting high with this drug, and its interactions with alcohol. 

It is a prescription medication used to reduce localized skeletal muscle spasms without interfering with the muscle’s actual function. It acts by blocking nerve impulses to the brain that cause muscle spasms and reduce pain signals. However, it does not result in altered perception per se. 

It should be in addition to physical therapy, rest, and other non-invasive treatments to manage acute sprains and overuse injuries.

Flexeril, Amrix, and Fexmid are brand names for cyclobenzaprine.

Side effects include:

  • dizziness
  • dry mouth
  • nausea
  • constipation
  • extreme tiredness
  • heartburn 
  • fatigue
  • blurred vision
  • irregular heartbeat
  • low blood pressure

In some cases, this drug may cause confusion, delirium, and cognitive impairment. It can also interact with many other medicines causing mild, moderate, and even severe drug-drug interactions. 

When taken on its own, it has little value to the recreational user seeking to get high. However, users report having no difficulty securing a prescription for it from their regular medical provider, walk-in clinics, or emergency department physicians. 

  • Users report experiencing a mild euphoric sensation due to the increased sense of relaxation after taking this drug.
  • Experts believe that users who do experience a mild high while taking Flexeril are reacting to the antidepressant qualities of this drug and take this side effect to be a sign that these users should consider seeking medical treatment for depression.

Some people seek it out for use as a sleep aid. However, users report that when combining it with other substances causes slowing down of brain processes. For example, when combined with alcohol and benzodiazepines, it can cause a semi-conscious state.

As with all types of prescription and over-the-counter medications, taking more than the recommended daily dose can cause multiple side effects, some of which can be life-threatening.

The most common symptoms of an overdose are extreme drowsiness and irregular or slow heartbeat. Other reported symptoms of acute overdose from this drug include nausea, dizziness, tremors, slurred speech, and hallucinations.

According to the 2011 DAWN Report published by the U.S. Department of Health and Human Services, approximately 0.9 percent of emergency-room visits for pharmaceutical overdoses involved Flexeril and other medications containing this drug. However, at least one fatality is known. 

The active ingredient is cyclobenzaprine HCI – a tricyclic amine salt that is both water-soluble and alcohol-soluble.

  • It is chemically related to tricyclic antidepressants (TCAs) such as Amoxapine, Doxepin, and Pamelor. 
  • Contrary to popular belief, it is not a narcotic.

It is a central nervous system (CNS) depressant. It reduces the frequency and severity of nerve impulses sent to the brain resulting in reduced muscle spasms and pain sensations associated with an acute muscle injury.

It has a notably long half-life of 18 hours, and it can take upwards of 90 hours to fully clear from the body, which is why many people who take this muscle relaxant report feeling the effects for an extended time.

According to the FDA, “Use only for short periods (up to two or three weeks) because adequate evidence of effectiveness for more prolonged use is not available.” 

Always be sure and consult with your physician about the proper dose of this drug or any medication.

Before 2003, the maximum recommended daily dosage was 60 mg. However, upon review of clinical studies, the manufacturer lowered the daily recommended dosage.

The suggested starting dosage of this drug for otherwise healthy adults is 5 mg taken up to 3 times per day for standard tablets. It is available in:

  • 5 mg tablets
  • 7.5 mg tablets
  • 10 mg tablets

It is also available in 15 mg and 30 mg extended-release capsules.

The maximum recommended dose is 30 mg per day, divided into three doses spaced 8 hours apart. Alternatively, it may be dosed as 2-15 mg extended-release capsules daily or 1-30 mg extended-release capsule daily.