Benadryl and Bile duct obstruction - a phase IV clinical study of FDA data

Summary:

Bile duct obstruction is reported as a side effect among people who take Benadryl (diphenhydramine hydrochloride), especially for people who are female, 60+ old, also take Demerol, and have Pancreatic carcinoma.

The phase IV clinical study analyzes which people have Bile duct obstruction when taking Benadryl. It is created by eHealthMe based on reports of 100,139 people who have side effects when taking Benadryl from the FDA, and is updated regularly.

What is Benadryl?

Benadryl has active ingredients of diphenhydramine hydrochloride. It is often used in allergies. eHealthMe is studying from 104,955 Benadryl users. Check the latest studies of Benadryl.

What is Bile duct obstruction?

Bile duct obstruction (blockage in the tubes that carry bile from the liver to the gallbladder) is found to be associated with 463 drugs and 625 conditions by eHealthMe. Check the latest studies of Bile duct obstruction.

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, 29, 2026

100,139 people reported to have side effects when taking Benadryl.
Among them, 32 people (0.03%) have Bile duct obstruction.

Could Benadryl cause Bile duct obstruction?

Among these 32 people:

What is the gender of people who have Bile duct obstruction when taking Benadryl? *

female: 68.75 %
male: 31.25 %

What is the age of people who have Bile duct obstruction when taking Benadryl? *

What are other drugs people take besides Benadryl? *

What are other side effects people have besides Bile duct obstruction? *

Gallstones (stone formation by bile component): 8 people, 25.00%
Nausea And Vomiting: 7 people, 21.88%
Abdominal Pain Upper: 7 people, 21.88%
Jaundice - Yellow Skin (a yellowish pigmentation of the skin): 7 people, 21.88%
Urinary Tract Infection: 6 people, 18.75%
Pancreatitis (inflammation of pancreas): 6 people, 18.75%
Rashes (redness): 6 people, 18.75%
Nausea (feeling of having an urge to vomit): 5 people, 15.62%
Abdominal Pain: 5 people, 15.62%
Weight Increased: 4 people, 12.50%

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): 4 people, 12.50%
High Blood Pressure: 4 people, 12.50%
Pancreatic Carcinoma (pancreatic cancer): 4 people, 12.50%
Acute Myeloid Leukaemia (acute cancer in which the bone marrow makes abnormal myeloblasts): 3 people, 9.38%
Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 3 people, 9.38%
Pain: 3 people, 9.38%
Primary Progressive Multiple Sclerosis (primary progressive inflammatory disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged): 2 people, 6.25%
Chronic Lymphocytic Leukaemia Refractory (a cancer of blood cells lymphocytes that no longer responds favourably to treatment): 2 people, 6.25%
Hypersensitivity: 2 people, 6.25%
Depression: 2 people, 6.25%

* Approximation only. Some reports may have incomplete information.

Do you take Benadryl and have Bile duct obstruction?

- Check whether Bile duct obstruction 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 Benadryl:

Benadryl (104,955 reports)

Browse all side effects of Benadryl:

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 Bile duct obstruction:

Bile duct obstruction (463 drugs)

Browse all the conditions that are associated with Bile duct obstruction:

Bile duct obstruction (625 conditions)

How the study uses the data?

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