Tysabri and Fistula - a phase IV clinical study of FDA data

Summary:

Fistula is reported as a side effect among people who take Tysabri (natalizumab), especially for people who are female, 40-49 old, have been taking the drug for 1 - 6 months also take Humira, and have Crohn's disease.

The phase IV clinical study analyzes which people have Fistula when taking Tysabri. It is created by eHealthMe based on reports of 220,870 people who have side effects when taking Tysabri from the FDA, and is updated regularly.

What is Tysabri?

Tysabri has active ingredients of natalizumab. It is often used in multiple sclerosis. eHealthMe is studying from 221,369 Tysabri users. Check the latest studies of Tysabri.

What is Fistula?

Fistula (an abnormal connection or passageway between two) is found to be associated with 843 drugs and 906 conditions by eHealthMe. Check the latest studies of Fistula.

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, 02, 2026

220,870 people reported to have side effects when taking Tysabri.
Among them, 59 people (0.03%) have Fistula.

Among these 59 people:

How long have people been on Tysabri when they have Fistula? *

What is the gender of people who have Fistula when taking Tysabri? *

female: 72.88 %
male: 27.12 %

What is the age of people who have Fistula when taking Tysabri? *

What are other drugs people take besides Tysabri? *

What are other side effects people have besides Fistula? *

Crohn's Disease (a condition that causes inflammation of the gastrointestinal tract): 12 people, 20.34%
Drug Ineffective: 9 people, 15.25%
Pain: 8 people, 13.56%
Headache (pain in head): 7 people, 11.86%
Weight Decreased: 6 people, 10.17%
Intestinal Obstruction: 5 people, 8.47%
Urinary Tract Infection: 5 people, 8.47%
Insomnia (sleeplessness): 4 people, 6.78%
Tinnitus (a ringing in the ears): 4 people, 6.78%
Enteritis Infectious (infection with feline parvovirus (fpv), also known as feline panleucopenia virus): 4 people, 6.78%

What are the existing conditions these people have? *

Crohn's Disease (a condition that causes inflammation of the gastrointestinal tract): 32 people, 54.24%
Depression: 3 people, 5.08%
Pain In Extremity: 2 people, 3.39%
Pain: 2 people, 3.39%
Vitamin B12 Deficiency: 1 person, 1.69%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 1 person, 1.69%
Bronchitis (inflammation of the mucous membrane in the bronchial tubes): 1 person, 1.69%
Constipation: 1 person, 1.69%
Diabetes: 1 person, 1.69%
Fatigue (feeling of tiredness): 1 person, 1.69%

* Approximation only. Some reports may have incomplete information.

Do you take Tysabri and have Fistula?

- Check whether Fistula 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 Tysabri:

Tysabri (221,369 reports)

Fistula treatments and more:

Fistula (16,274 reports)

Browse all side effects of Tysabri:

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 Fistula:

Fistula (843 drugs)

Browse all the conditions that are associated with Fistula:

Fistula (906 conditions)

How the study uses the data?

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