Flexeril and Initial insomnia - a phase IV clinical study of FDA data

Summary:

Initial insomnia 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 Xyrem, and have Narcolepsy.

The phase IV clinical study analyzes which people have Initial insomnia 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 Initial insomnia?

Initial insomnia (feeling of inadequate or poor-quality sleep) is found to be associated with 711 drugs and 690 conditions by eHealthMe. Check the latest studies of Initial insomnia.

eHealthMe: drug outcomes in the real world

eHealthMe runs one of the largest post-marketing drug safety studies in the world. We study millions of patients and 5,000 more each day. Our data-driven phase IV clinical trials have been referenced on 800+ peer-reviewed medical publications including The Lancet, Mayo Clinic Proceedings, and Nature. Tools to study our phase IV findings are available to the public, anonymous and free >>>.

On Sep, 03, 2026

34,789 people reported to have side effects when taking Flexeril.
Among them, 55 people (0.16%) have Initial insomnia.

Among these 55 people:

How long have people been on Flexeril when they have Initial insomnia? *

What is the gender of people who have Initial insomnia when taking Flexeril? *

female: 69.09 %
male: 30.91 %

What is the age of people who have Initial insomnia when taking Flexeril? *

What are other drugs people take besides Flexeril? *

What are other side effects people have besides Initial insomnia? *

Headache (pain in head): 12 people, 21.82%
Fatigue (feeling of tiredness): 12 people, 21.82%
Drug Ineffective: 12 people, 21.82%
Memory Loss: 10 people, 18.18%
Depression: 9 people, 16.36%
Weakness: 9 people, 16.36%
Nausea (feeling of having an urge to vomit): 9 people, 16.36%
Stress And Anxiety: 8 people, 14.55%
Chest Pain: 8 people, 14.55%
Pain: 7 people, 12.73%

What are the existing conditions these people have? *

Insomnia (sleeplessness): 10 people, 18.18%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 10 people, 18.18%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 8 people, 14.55%
Headache (pain in head): 4 people, 7.27%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 4 people, 7.27%
Occipital Neuralgia (a condition characterized by chronic pain in the upper neck): 3 people, 5.45%
Nausea And Vomiting: 3 people, 5.45%
Migraine (headache): 3 people, 5.45%
Quit Smoking: 3 people, 5.45%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 3 people, 5.45%

* Approximation only. Some reports may have incomplete information.

Do you take Flexeril and have Initial insomnia?

- Check whether Initial insomnia is associated with a drug or a condition
- Predict drug outcomes for up to one year with AI
- Get an AI agent to monitor your drugs continuously

Related studies:

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

Flexeril (38,308 reports)

Initial insomnia treatments and more:

Initial insomnia (12,139 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 Initial insomnia:

Initial insomnia (711 drugs)

Browse all the conditions that are associated with Initial insomnia:

Initial insomnia (690 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.