Ondansetron and Progressive multifocal leukoencephalopathy - a phase IV clinical study of FDA data

Summary:

Progressive multifocal leukoencephalopathy is reported as a side effect among people who take Ondansetron (ondansetron), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Tysabri, and have Multiple sclerosis.

The phase IV clinical study analyzes which people have Progressive multifocal leukoencephalopathy when taking Ondansetron. It is created by eHealthMe based on reports of 122,217 people who have side effects when taking Ondansetron from the FDA, and is updated regularly.

What is Ondansetron?

Ondansetron has active ingredients of ondansetron. It is often used in nausea. eHealthMe is studying from 122,739 Ondansetron users. Check the latest studies of Ondansetron.

What is Progressive multifocal leukoencephalopathy?

Progressive multifocal leukoencephalopathy (rapidly progressive neuromuscular disease caused by opportunistic infection of brain cells) is found to be associated with 591 drugs and 921 conditions by eHealthMe. Check the latest studies of Progressive multifocal leukoencephalopathy.

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 Aug, 22, 2026

122,217 people reported to have side effects when taking Ondansetron.
Among them, 71 people (0.06%) have Progressive multifocal leukoencephalopathy.

Could Ondansetron cause Progressive multifocal leukoencephalopathy?

Among these 71 people:

How long have people been on Ondansetron when they have Progressive multifocal leukoencephalopathy? *

What is the gender of people who have Progressive multifocal leukoencephalopathy when taking Ondansetron? *

female: 74.29 %
male: 25.71 %

What is the age of people who have Progressive multifocal leukoencephalopathy when taking Ondansetron? *

What are other drugs people take besides Ondansetron? *

What are other side effects people have besides Progressive multifocal leukoencephalopathy? *

Immune Reconstitution Syndrome (immune recovery syndrome): 8 people, 11.27%
Multiple Sclerosis Relapse (reoccurrence of a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 6 people, 8.45%
Dizziness: 6 people, 8.45%
Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 5 people, 7.04%
Headache (pain in head): 5 people, 7.04%
Hemiparesis (weakness on one side of the body): 4 people, 5.63%
Lymphoma (cancer that begins in immune system cells): 4 people, 5.63%
Encephalopathy (functioning of the brain is affected by some agent or condition): 4 people, 5.63%
Weakness: 3 people, 4.23%
Swallowing Difficulty: 3 people, 4.23%

What are the existing conditions these people have? *

Multiple Sclerosis (a nervous system disease that affects your brain and spinal cord. it damages the myelin sheath): 29 people, 40.85%
Non-Hodgkin's Lymphoma (malignant (cancer) cells form in the lymph system): 12 people, 16.90%
Chronic Lymphocytic Leukaemia (cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell)): 10 people, 14.08%
Constipation: 9 people, 12.68%
Pain: 8 people, 11.27%
Insomnia (sleeplessness): 8 people, 11.27%
High Blood Pressure: 7 people, 9.86%
High Blood Cholesterol: 7 people, 9.86%
Stress And Anxiety: 7 people, 9.86%
Muscle Spasms (muscle contraction): 6 people, 8.45%

* Approximation only. Some reports may have incomplete information.

Do you take Ondansetron and have Progressive multifocal leukoencephalopathy?

- Check whether Progressive multifocal leukoencephalopathy is associated with a drug or a condition
- Predict drug outcomes for up to one year with AI
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Related studies:

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

Ondansetron (122,739 reports)

Progressive multifocal leukoencephalopathy treatments and more:

Progressive multifocal leukoencephalopathy (13,731 reports)

How severe was Progressive multifocal leukoencephalopathy and when was it recovered:

Progressive multifocal leukoencephalopathy in Ondansetron

Expand to all the drugs that have ingredients of ondansetron:

Progressive multifocal leukoencephalopathy and drugs with ingredients of ondansetron

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 Ondansetron:

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 Progressive multifocal leukoencephalopathy:

Progressive multifocal leukoencephalopathy (591 drugs)

Browse all the conditions that are associated with Progressive multifocal leukoencephalopathy:

Progressive multifocal leukoencephalopathy (921 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on ondansetron (the active ingredients of Ondansetron) and Ondansetron (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.