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

Summary:

Tonic convulsion is reported as a side effect among people who take Effexor (venlafaxine hydrochloride), especially for people who are female, 30-39 old, have been taking the drug for < 1 month also take Ondansetron, and have Hyperparathyroidism secondary.

The phase IV clinical study analyzes which people have Tonic 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 99,493 Effexor users. Check the latest studies of Effexor.

What is Tonic convulsion?

Tonic convulsion (the person will quickly lose consciousness and the skeletal muscles will suddenly tense, often causing the extremities to be pulled towards the body or rigidly pushed away from it) is found to be associated with 162 drugs and 383 conditions by eHealthMe. Check the latest studies of Tonic convulsion.

On Jul, 17, 2026

92,291 people reported to have side effects when taking Effexor.
Among them, 21 people (0.02%) have Tonic convulsion.

Among these 21 people:

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

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

female: 85 %
male: 15 %

What is the age of people who have Tonic convulsion when taking Effexor? *

What are other drugs people take besides Effexor? *

Cyclophosphamide: 6 people, 28.57%
Emend: 6 people, 28.57%
Ondansetron: 6 people, 28.57%
Methylprednisolone Acetate: 5 people, 23.81%
Depakote: 4 people, 19.05%
Keppra: 4 people, 19.05%
Minirin: 2 people, 9.52%
Humalog: 1 person, 4.76%
Haldol: 1 person, 4.76%
Dilantin: 1 person, 4.76%

What are other side effects people have besides Tonic convulsion? *

Hyponatremia (abnormally low level of sodium in the blood; associated with dehydration): 6 people, 28.57%
Overdose: 3 people, 14.29%
Acute Kidney Failure: 2 people, 9.52%
Arrhythmias (irregular heartbeat): 2 people, 9.52%
Hypoglycemia (low blood sugar): 2 people, 9.52%
Intentional Self-Injury: 2 people, 9.52%
Electrocardiogram Qt Prolonged: 2 people, 9.52%
Weakness: 1 person, 4.76%
Drug Withdrawal Syndrome (interfere with normal social, occupational, or other functioning. are not due to another medical condition, drug use, or discontinuation): 1 person, 4.76%
Feeling Abnormal: 1 person, 4.76%

What are the existing conditions these people have? *

Hyperparathyroidism Secondary (an abnormally high concentration of parathyroid hormone in the blood, resulting in weakening of the bones through loss of calcium-secondary): 3 people, 14.29%
Type 1 Diabetes: 2 people, 9.52%
Migraine (headache): 2 people, 9.52%
Pain: 1 person, 4.76%
Insomnia (sleeplessness): 1 person, 4.76%
Dysmenorrhea (painful menstruation): 1 person, 4.76%
Bipolar Disorder (mood disorder): 1 person, 4.76%

* Approximation only. Some reports may have incomplete information.

Do you take Effexor and have Tonic convulsion?

- Check whether Tonic 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 (99,493 reports)

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 Tonic convulsion:

Tonic convulsion (162 drugs)

Browse all the conditions that are associated with Tonic convulsion:

Tonic convulsion (383 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.