Flexeril and Abnormal behavior - a phase IV clinical study of FDA data

Summary:

Abnormal behavior is reported as a side effect among people who take Flexeril (cyclobenzaprine hydrochloride), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Xanax, and have Stress and anxiety.

The phase IV clinical study analyzes which people have Abnormal behavior when taking Flexeril. It is created by eHealthMe based on reports of 34,789 people who have side effects when taking Flexeril from the FDA, and is updated regularly.

What is Flexeril?

Flexeril has active ingredients of cyclobenzaprine hydrochloride. It is often used in muscle spasms. eHealthMe is studying from 38,306 Flexeril users. Check the latest studies of Flexeril.

What is Abnormal behavior?

Abnormal behavior is found to be associated with 1,404 drugs and 1,902 conditions by eHealthMe. Check the latest studies of Abnormal behavior.

On Nov, 02, 2025

34,789 people reported to have side effects when taking Flexeril.
Among them, 151 people (0.43%) have Abnormal behavior.

Among these 151 people:

* Approximation only. Some reports may have incomplete information.

Do you take Flexeril and have Abnormal behavior?

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Related studies:

Effectiveness of, long term effects of, and alternative drugs to Flexeril:

Flexeril (38,306 reports)

Abnormal behavior treatments and more:

Abnormal behavior (51,307 reports)

How severe was Abnormal behavior and when was it recovered:

Abnormal behavior in Flexeril

Expand to all the drugs that have ingredients of cyclobenzaprine hydrochloride:

Abnormal behavior and drugs with ingredients of cyclobenzaprine hydrochloride (323 reports)

Sub-studies by gender and age:

Female: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Male: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Common Flexeril side effects:

Flexeril side effect: Nausea (feeling of having an urge to vomit) (3,094 reports)
Flexeril side effect: Drug ineffective (2,359 reports)

Browse all side effects of Flexeril:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Common drugs associated with Abnormal behavior:

Browse all the drugs that are associated with Abnormal behavior:

Abnormal behavior (1,404 drugs)

Common conditions associated with Abnormal behavior:

Depression: 3,069 reports
Adhd: 2,683 reports
Cigarette smoking: 1,988 reports
Parkinson's disease: 1,664 reports
Pain: 1,586 reports
Alternative medicine - pain relief: 1,584 reports
Schizophrenia: 1,544 reports
Anxiety: 1,538 reports
Jitters: 1,536 reports
Stress and anxiety: 1,518 reports

Browse all the conditions that are associated with Abnormal behavior:

Abnormal behavior (1,902 conditions)

Drugs similar to Flexeril and Abnormal behavior :

How the study uses the data?

The study uses data from the FDA. It is based on cyclobenzaprine hydrochloride (the active ingredients of Flexeril) and Flexeril (the brand name). Other drugs that have the same active ingredients (e.g. generic drugs) are not considered. Dosage of drugs is not considered in the study.

How to use the study?

DO NOT STOP MEDICATIONS without first consulting your doctor. If there are any serious or long term adverse effects discovered in the study, discuss the study with your doctor to ensure that proper medication management will be in place if applicable.

Who is eHealthMe?

With medical big data and proven AI/ML algorithms, eHealthMe provides a platform for everyone to run phase IV clinical trials. We study millions of patients and 5,000 more each day. Results of our real-world drug study have been referenced on 800+ peer-reviewed medical publications, including The Lancet, Mayo Clinic Proceedings, and Nature. Our analysis results are available to researchers, health care professionals, patients (testimonials), and software developers (open API).

WARNING, DISCLAIMER, USE FOR PUBLICATION

WARNING: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on eHealthMe.com is for informational purposes only, and is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare provider. All information is observation-only. Our phase IV clinical studies alone cannot establish cause-effect relationship. Different individuals may respond to medication in different ways. Every effort has been made to ensure that all information is accurate, up-to-date, and complete, but no guarantee is made to that effect. The use of the eHealthMe site and its content is at your own risk.

If you use this eHealthMe study on publication, please acknowledge it with a citation: study title, URL, accessed date.