Codeine and Muscle rigidity - a phase IV clinical study of FDA data

Summary:

Muscle rigidity is reported as a side effect among people who take Codeine (codeine sulfate), especially for people who are female, 30-39 old, have been taking the drug for < 1 month also take Lorazepam, and have Depression.

The phase IV clinical study analyzes which people have Muscle rigidity when taking Codeine. It is created by eHealthMe based on reports of 41,713 people who have side effects when taking Codeine from the FDA, and is updated regularly.

What is Codeine?

Codeine has active ingredients of codeine sulfate. It is often used in pain. eHealthMe is studying from 42,342 Codeine users. Check the latest studies of Codeine.

What is Muscle rigidity?

Muscle rigidity (muscle stiffness) is found to be associated with 793 drugs and 1,035 conditions by eHealthMe. Check the latest studies of Muscle rigidity.

On Feb, 08, 2026

41,713 people reported to have side effects when taking Codeine.
Among them, 130 people (0.31%) have Muscle rigidity.

Among these 130 people:

* Approximation only. Some reports may have incomplete information.

Do you take Codeine and have Muscle rigidity?

- Check whether Muscle rigidity 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 Codeine:

Codeine (42,342 reports)

Muscle rigidity treatments and more:

Muscle rigidity (16,888 reports)

How severe was Muscle rigidity and when was it recovered:

Muscle rigidity in Codeine

Expand to all the drugs that have ingredients of codeine sulfate:

Muscle rigidity and drugs with ingredients of codeine sulfate (130 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+

Browse all side effects of Codeine:

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 Muscle rigidity:

Muscle rigidity (793 drugs)

Browse all the conditions that are associated with Muscle rigidity:

Muscle rigidity (1,035 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on codeine sulfate (the active ingredients of Codeine) and Codeine (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.