Diphen and Syphilis - a phase IV clinical study of FDA data

Summary:

Syphilis is reported as a side effect among people who take Diphen (diphenhydramine hydrochloride), especially for people who are female, 60+ old, also take Acetaminophen, and have Gastroenteritis.

The phase IV clinical study analyzes which people have Syphilis when taking Diphen. It is created by eHealthMe based on reports of 113,958 people who have side effects when taking Diphen from the FDA, and is updated regularly.

What is Diphen?

Diphen has active ingredients of diphenhydramine hydrochloride. It is often used in insomnia. eHealthMe is studying from 115,432 Diphen users. Check the latest studies of Diphen.

What is Syphilis?

Syphilis (sexually transmitted , chronic bacterial disease caused by the spirochete treponema pallidum) is found to be associated with 128 drugs and 235 conditions by eHealthMe. Check the latest studies of Syphilis.

On Jan, 07, 2026

113,958 people reported to have side effects when taking Diphen.
Among them, 11 people (0.01%) have Syphilis.

Among these 11 people:

What is the gender of people who have Syphilis when taking Diphen? *

female: 100 %
male: 0.0 %

What is the age of people who have Syphilis when taking Diphen? *

What are other drugs people take besides Diphen? *

Acetaminophen: 9 people, 81.82%
Albuterol: 6 people, 54.55%
Atovaquone: 6 people, 54.55%
Dolutegravir: 5 people, 45.45%
Truvada: 5 people, 45.45%
Amoxicillin: 5 people, 45.45%
Descovy: 5 people, 45.45%
Verapamil Hydrochloride: 4 people, 36.36%
Trazodone Hydrochloride: 4 people, 36.36%
Levofloxacin: 4 people, 36.36%

What are other side effects people have besides Syphilis? *

Itching: 5 people, 45.45%
Pericoronitis (inflammation of the gingiva surrounding the crown of a tooth): 5 people, 45.45%
Alcohol Poisoning: 5 people, 45.45%
Drug Eruption (adverse drug reaction of the skin): 5 people, 45.45%
Folliculitis (infection of hair root): 5 people, 45.45%
Gastroenteritis (inflammation of stomach and intestine): 5 people, 45.45%
Hepatic Steatosis (fatty liver disease): 5 people, 45.45%
High Blood Pressure: 5 people, 45.45%
Water Intoxication (water poisoning): 5 people, 45.45%
Lip Erosion (peeling off of lip): 5 people, 45.45%

What are the existing conditions these people have? *

Alcohol Poisoning: 5 people, 45.45%
Hiv Infection: 5 people, 45.45%
Pneumonia: 5 people, 45.45%
Pericoronitis (inflammation of the gingiva surrounding the crown of a tooth): 5 people, 45.45%
Cytomegalovirus Infection: 5 people, 45.45%
Itching: 5 people, 45.45%
Gastroenteritis (inflammation of stomach and intestine): 5 people, 45.45%
Behcet's Syndrome (involves inflammation of the blood vessels): 3 people, 27.27%
Conjunctival Ulcer: 3 people, 27.27%
Eye Pain: 3 people, 27.27%

* Approximation only. Some reports may have incomplete information.

Do you take Diphen and have Syphilis?

- Check whether Syphilis 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 Diphen:

Diphen (115,432 reports)

Syphilis treatments and more:

Syphilis (1,148 reports)

Browse all side effects of Diphen:

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 Syphilis:

Syphilis (128 drugs)

Browse all the conditions that are associated with Syphilis:

Syphilis (235 conditions)

How the study uses the data?

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