What happens when you stop taking letrozole?
When you stop taking letrozole, side effects such as swelling, cough, hot flashes, and nausea, should improve within a week or 10 days. Some, such as high cholesterol, bone loss, and hair thinning may take many months to resolve. As long as you have taken it for at least 5 years, then letrozole should continue to reduce the risk of breast cancer coming back for many years after you stop taking it. Letrozole is usually taken for 5 years, but may be recommended for up to 10 years depending on individual circumstances. The American Society of Clinical Oncology (ASCO) recommends that 10 years should be the maximum duration of therapy, based on their 2019 clinical practice guideline update.
Do not stop taking letrozole without talking to your treatment team first. If you are not tolerating it well due to side effects, sometimes temporarily stopping it or switching to another hormone drug may be considered. If letrozole stops working and your breast cancer comes back, your specialist may prescribe another hormone drug. Not taking letrozole for the recommended time may increase the risk of your breast cancer coming back. Taking letrozole for long periods of time has been associated with an increased risk of bone fractures and heart side effects.
References
- Letrozole Updated 01/2024. Intas Pharmaceuticals Ltd. https://www.drugs.com/pro/letrozole.html
- Letrozole (Femara) Breast cancer now. https://breastcancernow.org/information-support/facing-breast-cancer/going-through-breast-cancer-treatment/hormone-therapy/letrozole-femara
Read next
How long do letrozole side effects last?
Most side effects of letrozole are mild and temporary, lasting only a few days or weeks until your body gets used to taking the medication. Some other side effects of letrozole take a few months to develop and tend to persist long term until you stop taking letrozole. The half-life of letrozole is 2 days, so once you stop taking letrozole, you might continue to experience side effects for about a week to 10 days after your last dose. Continue reading
When is the best time of day to take letrozole?
You can take letrozole (Femara) in the morning or evening, but you should take it at about the same time each day. Taking it at the same time each day will help you to remember your dose. Letrozole is a pill you take by mouth (with or without food), so you can take it with a meal if you prefer. If you miss a dose, do not double your dose the next day. Continue reading
Is letrozole a form of chemotherapy?
Letrozole is not chemotherapy, it is a type of hormone therapy that is used to treat people with breast cancer that is hormone receptor-positive. If your cancer is hormone receptor-negative, then letrozole will not be of any benefit. Traditional chemotherapy agents stop cancer cells from growing, dividing, and making more cells. Letrozole works by blocking the action of the enzyme aromatase, which prevents the body from converting androgens into estrogens. Estrogen is a hormone that causes estrogen receptor-positive (ER+) breast cancer to grow. Letrozole belongs to the class of medicines known as aromatase inhibitors. Continue reading
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Drug information
- Letrozole Information for Consumers
- Letrozole prescribing info & package insert (for Health Professionals)
- Side Effects of Letrozole (detailed)
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