Duopa and On and off phenomenon - a phase IV clinical study of FDA data

Summary:

On and off phenomenon is reported as a side effect among people who take Duopa (carbidopa; levodopa), especially for people who are male, 60+ old, have been taking the drug for < 1 month also take Sinemet, and have Parkinson's disease.

The phase IV clinical study analyzes which people have On and off phenomenon when taking Duopa. It is created by eHealthMe based on reports of 8,206 people who have side effects when taking Duopa from the FDA, and is updated regularly.

What is Duopa?

Duopa has active ingredients of carbidopa; levodopa. eHealthMe is studying from 8,208 Duopa users. Check the latest studies of Duopa.

What is On and off phenomenon?

On and off phenomenon is found to be associated with 194 drugs and 183 conditions by eHealthMe. Check the latest studies of On and off phenomenon.

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

8,206 people reported to have side effects when taking Duopa.
Among them, 223 people (2.72%) have On and off phenomenon.

Could Duopa cause On and off phenomenon?

Among these 223 people:

How long have people been on Duopa when they have On and off phenomenon? *

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What is the gender of people who have On and off phenomenon when taking Duopa? *

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* Approximation only. Some reports may have incomplete information.

Do you take Duopa and have On and off phenomenon?

- Check whether On and off phenomenon 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 Duopa:

Duopa (8,208 reports)

On and off phenomenon treatments and more:

On and off phenomenon (11,494 reports)

How severe was On and off phenomenon and when was it recovered:

On and off phenomenon in Duopa

Expand to all the drugs that have ingredients of carbidopa; levodopa:

On and off phenomenon and drugs with ingredients of carbidopa; levodopa (653 reports)

Sub-studies by gender and age:

Female: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Male: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Browse all side effects of Duopa:

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 On and off phenomenon:

On and off phenomenon (194 drugs)

Browse all the conditions that are associated with On and off phenomenon:

On and off phenomenon (183 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on carbidopa; levodopa (the active ingredients of Duopa) and Duopa (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.