Flexeril and Drug level decreased - a phase IV clinical study of FDA data

Summary:

Drug level decreased is reported as a side effect among people who take Flexeril (cyclobenzaprine hydrochloride), especially for people who are female, 50-59 old, have been taking the drug for < 1 month also take Oxycodone, and have Crohn's disease.

The phase IV clinical study analyzes which people have Drug level decreased 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 38,308 Flexeril users. Check the latest studies of Flexeril.

What is Drug level decreased?

Drug level decreased is found to be associated with 588 drugs and 696 conditions by eHealthMe. Check the latest studies of Drug level decreased.

On Jul, 26, 2026

34,789 people reported to have side effects when taking Flexeril.
Among them, 13 people (0.04%) have Drug level decreased.

Could Flexeril cause Drug level decreased?

Among these 13 people:

How long have people been on Flexeril when they have Drug level decreased? *

What is the gender of people who have Drug level decreased when taking Flexeril? *

female: 83.33 %
male: 16.67 %

What is the age of people who have Drug level decreased when taking Flexeril? *

What are other drugs people take besides Flexeril? *

What are other side effects people have besides Drug level decreased? *

Melaena (the passage of black, tarry stools): 5 people, 38.46%
Diarrhea: 4 people, 30.77%
Drug Ineffective: 4 people, 30.77%
Intestinal Polyp (small growths in the bowel with the potential for further growth): 3 people, 23.08%
Weight Decreased: 3 people, 23.08%
Anaemia (lack of blood): 3 people, 23.08%
Crohn's Disease (a condition that causes inflammation of the gastrointestinal tract): 3 people, 23.08%
Pain: 3 people, 23.08%
Faeces Discolored: 3 people, 23.08%
Nausea (feeling of having an urge to vomit): 3 people, 23.08%

What are the existing conditions these people have? *

Crohn's Disease (a condition that causes inflammation of the gastrointestinal tract): 7 people, 53.85%
Neuralgia (pain in one or more nerves): 5 people, 38.46%
Stress And Anxiety: 3 people, 23.08%
High Blood Pressure: 3 people, 23.08%
Asthma: 3 people, 23.08%
Cancer Pain: 3 people, 23.08%
Panic Disorder: 3 people, 23.08%
Diabetes: 3 people, 23.08%
Hypersensitivity: 3 people, 23.08%
Intervertebral Disc Protrusion (spinal disc protrusion): 3 people, 23.08%

* Approximation only. Some reports may have incomplete information.

Do you take Flexeril and have Drug level decreased?

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Related studies:

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

Flexeril (38,308 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

Browse all the drugs that are associated with Drug level decreased:

Drug level decreased (588 drugs)

Browse all the conditions that are associated with Drug level decreased:

Drug level decreased (696 conditions)

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.