Medicine (MD/DO)
Neurology, Ophthalmology & Otology
Antispasmodic Agents
Cyclobenzaprine (Flexeril)

Master Cyclobenzaprine (Flexeril) with Picmonic for Medicine

With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.

Cyclobenzaprine (Flexeril)

Recommended Picmonics

picmonic thumbnail
Nondepolarizing Neuromuscular Blocking Drugs
picmonic thumbnail
picmonic thumbnail

Cyclobenzaprine (Flexeril)

Centrally-Acting Muscle Relaxer
Muscle-guy with brain getting a massage

Cyclobenzaprine is a medication that acts as a muscle relaxer through mechanisms that moderate the interaction between the central nervous system and neuromuscular synapse.

Act on Alpha and Gamma Motor Neurons

Cyclobenzaprine is thought to work by acting on alpha and gamma motor neurons. Recall that alpha neurons are lower motor neurons that synapse at the motor end plate on extrafusal skeletal muscle fibers and help permit voluntary muscle contraction, while gamma motor neurons synapse on intrafusal fibers. While they do not contribute significantly to contraction, they aid in monitoring the tension in muscle fibers and providing a feedback loop that aids in maintaining tone and muscle activation in response to stretch.

Related to Tricyclic Antidepressants (TCAs)

Cyclobenzaprine is pharmacologically related to tricyclic antidepressants, or TCAs, and hence can exert many of the same unwanted side effects.

Muscle Spasms
Muscle-man Spaceship

Cyclobenzaprine is commonly used in treating painful muscle spasms associated with various conditions. Of note, it is not useful in treating spasticity due to neurologic conditions such as cerebral palsy.

Back Pain
Back Pain-bolt

Cyclobenzaprine is often used in the treatment of back pain thought to be musculoskeletal in nature. It is best used following acute injury during pain may be caused by muscle spasms, and generally should not be used long-term as it will not provide permanent relief.

MAO Inhibitors
MAO-inhibited with caution tape

Patients taking monamine oxidase (MAO) inhibitors should not take cyclobenzaprine. Since cyclobenzaprine is related pharmacologically to tricyclic antidepressants (TCAs), one of its partial actions is to prevent reuptake of certain neurotransmitters, namely norepinephrine, serotonin, and epinephrine. Taking this in concert with a MAO inhibitor could therefore cause dangerous buildup of these amines at the synapse and even lead to serotonin syndrome.

Serotonin Syndrome
Silver-tonic Savage

The most dangerous potential adverse reaction to cyclobenzaprine is serotonin syndrome. This is caused by the partial TCA-like action that cyclobenzaprine has at the neuron synapse, by preventing the re-uptake of the neurotransmitters serotonin, norepinephrine, and epinephrine. Serotonin syndrome is typically seen only in the context of polypharmacy (patients taking multiple mediations that affect the release and processing of serotonin and other catecholamines) or overdose.


Drowsiness is one of the most commonly reported side effects of cyclobenzaprine.

Broken Arrhythmia-drum

A potentially dangerous side effect of cyclobenzaprine is arrhythmia, specifically tachycardia and/or QT prolongation. These are again mediated by the partial TCA-like activity that cyclobenzaprine exibits.


Take the Cyclobenzaprine (Flexeril) Quiz

Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.

It's worth every penny

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Memorize facts with phonetic mnemonics

Ace Your Medicine (MD/DO) Classes & Exams with Picmonic:

Over 1,890,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Medicine (MD/DO) student study app.

Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medicine (MD/DO) education. Whether you’re studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, we’re here to help.

Works better than traditional Medicine (MD/DO) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.