Benadryl and Bladder spasm - a phase IV clinical study of FDA data

Summary:

Bladder spasm is reported as a side effect among people who take Benadryl (diphenhydramine hydrochloride), especially for people who are female, 60+ old, have been taking the drug for < 1 month also take Tylenol, and have Encephalitis autoimmune.

The phase IV clinical study analyzes which people have Bladder spasm 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 104,954 Benadryl users. Check the latest studies of Benadryl.

What is Bladder spasm?

Bladder spasm is found to be associated with 342 drugs and 467 conditions by eHealthMe. Check the latest studies of Bladder spasm.

On Jul, 06, 2026

100,139 people reported to have side effects when taking Benadryl.
Among them, 73 people (0.07%) have Bladder spasm.

Among these 73 people:

How long have people been on Benadryl when they have Bladder spasm? *

What is the gender of people who have Bladder spasm when taking Benadryl? *

female: 83.33 %
male: 16.67 %

What is the age of people who have Bladder spasm when taking Benadryl? *

What are other drugs people take besides Benadryl? *

Tylenol: 25 people, 34.25%
Acetaminophen: 19 people, 26.03%
Pantoprazole Sodium: 18 people, 24.66%
Myrbetriq: 18 people, 24.66%
Prednisone: 18 people, 24.66%
Calcium: 17 people, 23.29%
Methylprednisolone Sodium Succinate: 15 people, 20.55%
Risedronate Sodium: 14 people, 19.18%
Levothyroxine Sodium: 14 people, 19.18%
Keppra: 14 people, 19.18%

What are other side effects people have besides Bladder spasm? *

Urinary Tract Infection: 39 people, 53.42%
Fatigue (feeling of tiredness): 36 people, 49.32%
Infusion Related Reaction: 27 people, 36.99%
Neuropathy Peripheral (surface nerve damage): 26 people, 35.62%
Fall: 24 people, 32.88%
Fever: 22 people, 30.14%
Headache (pain in head): 21 people, 28.77%
High Blood Pressure: 19 people, 26.03%
Weakness: 19 people, 26.03%
Numbness And Tingling (unusual prickling sensations): 18 people, 24.66%

What are the existing conditions these people have? *

Encephalitis Autoimmune (autoimmune origin disturbances of consciousness and pyramidal signs, inflammation of the brain): 14 people, 19.18%
Multiple Myeloma (cancer of the plasma cells): 11 people, 15.07%
Rheumatoid Arthritis (a chronic progressive disease causing inflammation in the joints): 11 people, 15.07%
High Blood Pressure: 11 people, 15.07%
Urinary Tract Infection: 10 people, 13.70%
Relapsing-Remitting Multiple Sclerosis (reoccurrence of an inflammatory disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged): 9 people, 12.33%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 8 people, 10.96%
Cataplexy (loss of muscle tone accompanied by full conscious awareness): 8 people, 10.96%
Muscle Spasms (muscle contraction): 6 people, 8.22%
Pain: 6 people, 8.22%

* Approximation only. Some reports may have incomplete information.

Do you take Benadryl and have Bladder spasm?

- Check whether Bladder spasm 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 (104,954 reports)

Bladder spasm treatments and more:

Bladder spasm (3,924 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 Bladder spasm:

Bladder spasm (342 drugs)

Browse all the conditions that are associated with Bladder spasm:

Bladder spasm (467 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.