Phenergan and Cystitis interstitial - a phase IV clinical study of FDA data

Summary:

Cystitis interstitial is reported as a side effect among people who take Phenergan (promethazine hydrochloride), especially for people who are female, 60+ old, also take Ativan, and have Multiple myeloma.

The phase IV clinical study analyzes which people have Cystitis interstitial when taking Phenergan. It is created by eHealthMe based on reports of 24,254 people who have side effects when taking Phenergan from the FDA, and is updated regularly.

What is Phenergan?

Phenergan has active ingredients of promethazine hydrochloride. It is often used in nausea. eHealthMe is studying from 25,312 Phenergan users. Check the latest studies of Phenergan.

What is Cystitis interstitial?

Cystitis interstitial (unknown cause characterized by bladder pain) is found to be associated with 333 drugs and 439 conditions by eHealthMe. Check the latest studies of Cystitis interstitial.

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, 21, 2026

24,254 people reported to have side effects when taking Phenergan.
Among them, 18 people (0.07%) have Cystitis interstitial.

Could Phenergan cause Cystitis interstitial?

Among these 18 people:

What is the gender of people who have Cystitis interstitial when taking Phenergan? *

female: 100 %
male: 0.0 %

What is the age of people who have Cystitis interstitial when taking Phenergan? *

What are other drugs people take besides Phenergan? *

What are other side effects people have besides Cystitis interstitial? *

Dehydration (dryness resulting from the removal of water): 15 people, 83.33%
Fever: 14 people, 77.78%
Weakness: 13 people, 72.22%
Urinary Tract Infection: 13 people, 72.22%
Pain In Extremity: 13 people, 72.22%
Osteoarthritis (a joint disease caused by cartilage loss in a joint): 12 people, 66.67%
Movement Disorder (neurological syndromes where they may be excess of movement or a paucity of movement that is not connected to weakness): 12 people, 66.67%
Pain In Jaw: 12 people, 66.67%
Pneumonia: 12 people, 66.67%
Sinusitis (inflammation of sinus): 12 people, 66.67%

What are the existing conditions these people have? *

Multiple Myeloma (cancer of the plasma cells): 11 people, 61.11%
High Blood Pressure: 5 people, 27.78%
Febrile Neutropenia (fever with reduced white blood cells): 5 people, 27.78%
Pain: 4 people, 22.22%
Urinary Tract Infection: 3 people, 16.67%
Ovarian Cancer (cancer of ovary): 3 people, 16.67%
Narcolepsy (brain's inability to regulate sleep-wake cycles normally): 1 person, 5.56%
Mitral Valve Prolapse (heart's mitral valve doesn't work well): 1 person, 5.56%
Migraine (headache): 1 person, 5.56%
Gastroesophageal Reflux Disease (a condition in which stomach contents leak backward from the stomach into the oesophagus): 1 person, 5.56%

* Approximation only. Some reports may have incomplete information.

Do you take Phenergan and have Cystitis interstitial?

- Check whether Cystitis interstitial 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 Phenergan:

Phenergan (25,312 reports)

Browse all side effects of Phenergan:

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 Cystitis interstitial:

Cystitis interstitial (333 drugs)

Browse all the conditions that are associated with Cystitis interstitial:

Cystitis interstitial (439 conditions)

Related publications that referenced our studies

Teimoory M, Arefi M, Behnoush B, Bastani B, "Promethazine and Treatment Refractory Agitation in Clonidine Toxicity", International Journal of Medical Toxicology and Forensic Medicine, 2013 Mar .
Teimoory M, Arefi M, Behnoush B, Bastani B, "Promethazine and Treatment Refractory Agitation in Clonidine Toxicity", International Journal of Medical Toxicology and Forensic Medicine, 2013 Mar .

How the study uses the data?

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