In general, side effects are common with almost any medication. What’s less common are side effects that can complicate your recovery from the very condition you’re looking to treat. Case in point: medications that can cause weight gain.
Research suggests a growing number of people take drugs that cause weight gain — most notably, for conditions that are exacerbated by excess weight. Drawing on data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES), a recent study published in Obesity found that 1 in 5 U.S. adults take at least one medication that causes weight gain.
As side effects go, weight gain may not seem like a big deal, especially if you’re treating a life-threatening condition. But in less serious scenarios, the added weight can compromise your overall health. People with obesity are at increased risk for many serious diseases and health conditions, including heart disease, stroke, and death, according to the Centers for Disease Control and Prevention (CDC). Even modest weight gain — we’re talking five to 20 pounds — can have negative health effects, one study shows.
What is Anastrozole?
Anastrozole, sold under the brand name Arimidex among others, is a medication used with other treatments, such as surgery or radiation, to treat early breast cancer in women who have experienced menopause (change of life; end of monthly menstrual periods). This medication is also used in women, who have experienced menopause, as the first treatment for breast cancer that has spread within the breast or to other areas of the body. This medication is also used to treat breast cancer in women whose breast cancer has worsened after taking tamoxifen (Nolvadex).
Anastrozole is considered a hormone therapy rather than a traditional chemotherapy medication. Chemotherapy is used to target and kill cancer cells.
How does anastrozole work?
Your blood carries estrogen to cells and tissues throughout your body. Estrogen plays a vital role in sexual development and reproductive health. But estrogen is also a carcinogen, which means it has the potential to cause cancer. In estrogen-dependent cancer, estrogen fuels cancer’s growth. Anastrozole belongs to a class of medications called nonsteroidal aromatase inhibitors, it works by lowering the amount of estrogen the body makes. This can slow or stop the growth of many types of breast cancer cells that need estrogen to grow.
How should anastrozole be used?
Anastrozole comes as a tablet to take by mouth. It is usually taken once a day with or without food. Take anastrozole at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. The typical dose is 1 mg by mouth daily. Take anastrozole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
You may need to take anastrozole for several years or longer. Continue to take anastrozole even if you feel well. Do not stop taking anastrozole without talking to your doctor. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.
Does anastrozole cause weight gain?
Yes, anastrozole can cause your body to hold onto fat more easily, which can lead to weight gain. In clinical studies involving women with early breast cancer, 9% of those taking anastrozole had weight gain while in studies of women with advanced breast cancer, 2% of those taking anastrozole had weight gain.
Lipoprotein lipase (LPL) is a gatekeeper for the delivery of fat to tissues in the body. In adipose tissue, LPL activity increases upon feeding and decreases with starvation. Thus LPL plays an important role in regulating rates of triglyceride deposition in adipocytes according to the energy needs of the organism. The hormone estrogen is known to suppress LPL activity on fat cells.
By introducing anastrozole which suppresses the amount of estrogen the body makes, LPL pulls more fat into fat cells and stores it there, this explains why many people gain weight while taking anastrozole.
For more information on the possible side effects of anastrozole, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome including weight gain.
