Welchol and Nightmares - a phase IV clinical study of FDA data

Summary:

Nightmares is reported as a side effect among people who take Welchol (colesevelam hydrochloride), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Chantix, and have Fungal infection.

The phase IV clinical study analyzes which people have Nightmares when taking Welchol. It is created by eHealthMe based on reports of 10,884 people who have side effects when taking Welchol from the FDA, and is updated regularly.

What is Welchol?

Welchol has active ingredients of colesevelam hydrochloride. It is often used in high blood cholesterol. eHealthMe is studying from 11,309 Welchol users. Check the latest studies of Welchol.

What is Nightmares?

Nightmares (unpleasant dreams) is found to be associated with 1,324 drugs and 1,914 conditions by eHealthMe. Check the latest studies of Nightmares.

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

10,884 people reported to have side effects when taking Welchol.
Among them, 24 people (0.22%) have Nightmares.

Among these 24 people:

How long have people been on Welchol when they have Nightmares? *

What is the gender of people who have Nightmares when taking Welchol? *

female: 60.87 %
male: 39.13 %

What is the age of people who have Nightmares when taking Welchol? *

What are other drugs people take besides Welchol? *

What are other side effects people have besides Nightmares? *

Stress And Anxiety: 8 people, 33.33%
Fatigue (feeling of tiredness): 6 people, 25.00%
Headache (pain in head): 6 people, 25.00%
Nausea (feeling of having an urge to vomit): 5 people, 20.83%
Nausea And Vomiting: 5 people, 20.83%
Nervousness: 4 people, 16.67%
Tremor (trembling or shaking movements in one or more parts of your body): 4 people, 16.67%
Feeling Abnormal: 4 people, 16.67%
Depression: 3 people, 12.50%
Insomnia (sleeplessness): 3 people, 12.50%

What are the existing conditions these people have? *

Stress And Anxiety: 4 people, 16.67%
Pain: 4 people, 16.67%
Depression: 4 people, 16.67%
Fungal Infection: 4 people, 16.67%
Quit Smoking: 3 people, 12.50%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 3 people, 12.50%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 3 people, 12.50%
Hiv Infection: 2 people, 8.33%
Bacterial Infection: 2 people, 8.33%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 2 people, 8.33%

* Approximation only. Some reports may have incomplete information.

Do you take Welchol and have Nightmares?

- Check whether Nightmares 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 Welchol:

Welchol (11,309 reports)

Nightmares treatments and more:

Nightmares (42,077 reports)

Browse all side effects of Welchol:

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 Nightmares:

Nightmares (1,324 drugs)

Browse all the conditions that are associated with Nightmares:

Nightmares (1,914 conditions)

How the study uses the data?

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