Effexor and Grand mal convulsion - a phase IV clinical study of FDA data

Summary:

Grand mal convulsion is reported as a side effect among people who take Effexor (venlafaxine hydrochloride), especially for people who are female, 20-29 old, have been taking the drug for < 1 month also take Xanax, and have Multiple sclerosis.

The phase IV clinical study analyzes which people have Grand mal convulsion when taking Effexor. It is created by eHealthMe based on reports of 92,291 people who have side effects when taking Effexor from the FDA, and is updated regularly.

What is Effexor?

Effexor has active ingredients of venlafaxine hydrochloride. It is often used in depression. eHealthMe is studying from 99,496 Effexor users. Check the latest studies of Effexor.

What is Grand mal convulsion?

Grand mal convulsion (a type of generalized seizure that affects the entire brain) is found to be associated with 918 drugs and 1,337 conditions by eHealthMe. Check the latest studies of Grand mal convulsion.

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, 30, 2026

92,291 people reported to have side effects when taking Effexor.
Among them, 373 people (0.4%) have Grand mal convulsion.

Could Effexor cause Grand mal convulsion?

Among these 373 people:

How long have people been on Effexor when they have Grand mal convulsion? *

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What is the gender of people who have Grand mal convulsion when taking Effexor? *

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* Approximation only. Some reports may have incomplete information.

Do you take Effexor and have Grand mal convulsion?

- Check whether Grand mal convulsion 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 Effexor:

Effexor (99,496 reports)

Grand mal convulsion treatments and more:

Grand mal convulsion (19,182 reports)

How severe was Grand mal convulsion and when was it recovered:

Grand mal convulsion in Effexor

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

Grand mal convulsion and drugs with ingredients of venlafaxine hydrochloride

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 Effexor:

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 Grand mal convulsion:

Grand mal convulsion (918 drugs)

Browse all the conditions that are associated with Grand mal convulsion:

Grand mal convulsion (1,337 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on venlafaxine hydrochloride (the active ingredients of Effexor) and Effexor (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.