Pegasys and Erythema nodosum - a phase IV clinical study of FDA data


Erythema nodosum is found among people who take Pegasys, especially for people who are female, 40-49 old, have been taking the drug for 1 - 6 months.

The phase IV clinical study analyzes which people take Pegasys and have Erythema nodosum. It is created by eHealthMe based on reports of 56,935 people who have side effects when taking Pegasys from the FDA, and is updated regularly. You can use the study as a second opinion to make health care decisions.

Phase IV trials are used to detect adverse drug outcomes and monitor drug effectiveness in the real world. With medical big data and AI algorithms, eHealthMe is running millions of phase IV trials and makes the results available to the public. Our original studies have been referenced on 600+ medical publications including The Lancet, Mayo Clinic Proceedings, and Nature.

On Oct, 01, 2022

56,935 people reported to have side effects when taking Pegasys.
Among them, 31 people (0.05%) have Erythema nodosum.

What is Pegasys?

Pegasys has active ingredients of peginterferon alfa 2a. It is often used in hepatitis c. eHealthMe is studying from 57,043 Pegasys users for its effectiveness, alternative drugs and more.

What is Erythema nodosum?

Erythema nodosum (skin inflammation that results in reddish, painful, tender lumps most commonly located in the front of the legs below) is found to be associated with 868 drugs and 465 conditions by eHealthMe.

Number of Pegasys and Erythema nodosum reports submitted per year:

Could Pegasys cause Erythema nodosum?

Time on Pegasys when people have Erythema nodosum *:

  • < 1 month: 0.0 %
  • 1 - 6 months: 85.71 %
  • 6 - 12 months: 14.29 %
  • 1 - 2 years: 0.0 %
  • 2 - 5 years: 0.0 %
  • 5 - 10 years: 0.0 %
  • 10+ years: 0.0 %

Gender of people who have Erythema nodosum when taking Pegasys *:

  • female: 86.67 %
  • male: 13.33 %

Age of people who have Erythema nodosum when taking Pegasys *:

  • 0-1: 0.0 %
  • 2-9: 0.0 %
  • 10-19: 0.0 %
  • 20-29: 0.0 %
  • 30-39: 3.7 %
  • 40-49: 55.56 %
  • 50-59: 29.63 %
  • 60+: 11.11 %

Common drugs people take besides Pegasys *:

  1. Ribavirin: 11 people, 35.48%
  2. Copegus: 10 people, 32.26%
  3. Rebetol: 3 people, 9.68%
  4. Victrelis: 2 people, 6.45%
  5. Incivek: 2 people, 6.45%
  6. Banan: 2 people, 6.45%
  7. Nplate: 2 people, 6.45%
  8. Amlodipine: 1 person, 3.23%
  9. Citalopram Hydrobromide: 1 person, 3.23%
  10. Clonazepam: 1 person, 3.23%

Common side effects people have besides Erythema nodosum *:

  1. Sarcoidosis (an inflammatory disease that affects multiple organs in the body, but mostly the lungs and lymph glands): 5 people, 16.13%
  2. White Blood Cell Count Decreased: 4 people, 12.90%
  3. Vasculitis (inflammation of a blood vessel or blood vessels): 4 people, 12.90%
  4. Nodule (a small rock or mineral cluster): 4 people, 12.90%
  5. Granuloma (a small area of inflammation due to tissue injury): 4 people, 12.90%
  6. Fever: 2 people, 6.45%
  7. Back Pain: 2 people, 6.45%
  8. Haemoglobin Decreased: 2 people, 6.45%
  9. Pain: 2 people, 6.45%
  10. Rashes (redness): 2 people, 6.45%

Common conditions people have *:

  1. Thrombocytopenia (decrease of platelets in blood): 1 person, 3.23%
  2. Menstruation Irregular: 1 person, 3.23%
  3. Idiopathic Thrombocytopenic Purpura (Itp) (bleeding disorder in which the immune system destroys platelets, which are necessary for normal blood clotting): 1 person, 3.23%
  4. High Blood Pressure: 1 person, 3.23%
  5. Gastritis (inflammation of stomach): 1 person, 3.23%
  6. Anaemia (lack of blood): 1 person, 3.23%
  7. Agranulocytosis (a deficiency of granulocytes in the blood, causing increased vulnerability to infection): 1 person, 3.23%

* Approximation only. Some reports may have incomplete information.

Do you take Pegasys and have Erythema nodosum?

Check whether Erythema nodosum is associated with a drug or a condition

How to use the study?

You can discuss the study with your doctor, to ensure that all drug risks and benefits are fully discussed and understood.

Related studies

How severe was Erythema nodosum and when was it recovered:

Expand to all the drugs that have ingredients of peginterferon alfa 2a:

Alternative drugs to, pros and cons of Pegasys:

Common Pegasys side effects:

Browse all side effects of Pegasys:

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

Erythema nodosum treatments and more:

COVID vaccines that are related to Erythema nodosum:

Common drugs associated with Erythema nodosum:

All the drugs that are associated with Erythema nodosum:

Common conditions associated with Erythema nodosum:

All the conditions that are associated with Erythema nodosum:

How the study uses the data?

The study uses data from the FDA. It is based on peginterferon alfa 2a (the active ingredients of Pegasys) and Pegasys (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.

Who is eHealthMe?

With medical big data and proven AI 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 600+ 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: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on 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.

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