Femara and Svc obstruction - a phase IV clinical study of FDA data

Summary:

Svc obstruction is reported as a side effect among people who take Femara (letrozole), especially for people who are female, 40-49 old, have been taking the drug for 1 - 6 months also take Zometa, and have Breast cancer metastatic.

The phase IV clinical study analyzes which people have Svc obstruction when taking Femara. It is created by eHealthMe based on reports of 19,093 people who have side effects when taking Femara from the FDA, and is updated regularly.

What is Femara?

Femara has active ingredients of letrozole. It is often used in breast cancer. eHealthMe is studying from 19,630 Femara users. Check the latest studies of Femara.

What is Svc obstruction?

Svc obstruction (superior vena cava obstruction (svco) is an uncommon complication of lung cancer) is found to be associated with 214 drugs and 336 conditions by eHealthMe. Check the latest studies of Svc obstruction.

On Jul, 06, 2026

19,093 people reported to have side effects when taking Femara.
Among them, 26 people (0.14%) have Svc obstruction.

Among these 26 people:

How long have people been on Femara when they have Svc obstruction? *

What is the gender of people who have Svc obstruction when taking Femara? *

female: 88.46 %
male: 11.54 %

What is the age of people who have Svc obstruction when taking Femara? *

What are other drugs people take besides Femara? *

What are other side effects people have besides Svc obstruction? *

Osteonecrosis Of Jaw (death of bone of jaw): 24 people, 92.31%
Lymph Follicular Hypertrophy (an increase in the size of the lymph node follicles): 24 people, 92.31%
Pain: 23 people, 88.46%
General Physical Health Deterioration (weak health status): 23 people, 88.46%
Thrombocytopenia (decrease of platelets in blood): 22 people, 84.62%
Osteoradionecrosis (irradiation of bones causes damage to osteocytes and impairs the blood supply): 20 people, 76.92%
Weight Decreased: 19 people, 73.08%
Neoplasm Malignant (cancer tumour): 19 people, 73.08%
Joint Pain: 19 people, 73.08%
Hiatal Hernia (hernia resulting from the protrusion of part of the stomach through the diaphragm): 19 people, 73.08%

What are the existing conditions these people have? *

Breast Cancer Metastatic: 17 people, 65.38%
Nausea (feeling of having an urge to vomit): 1 person, 3.85%
Metastases To Bone (cancer spreads to bone): 1 person, 3.85%
Gastroesophageal Cancer: 1 person, 3.85%

* Approximation only. Some reports may have incomplete information.

Do you take Femara and have Svc obstruction?

- Check whether Svc obstruction 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 Femara:

Femara (19,630 reports)

Browse all side effects of Femara:

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 Svc obstruction:

Svc obstruction (214 drugs)

Browse all the conditions that are associated with Svc obstruction:

Svc obstruction (336 conditions)

How the study uses the data?

The study uses data from the FDA. It is based on letrozole (the active ingredients of Femara) and Femara (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.