Letrozole (Femara) Side Effects

Possible side effects of letrozole are listed below. Call your doctor for medical advice about side effects if they are severe or continue after a few days.

• Hot flashes 
• Night sweats
• Nausea
• Vomiting
• Diarrhea
• Constipation
• Heartburn
• Stomach pain
• Loss of appetite
• Weight gain or weight loss
• Muscle, bone, or joint pain
• Tiredness
• Weakness
• Dizziness
• Headache
• Sleep problems
• Vaginal irritation or bleeding
• Breast pain
• Swelling of the hands, lower legs, ankles, or feet
• Blurred vision
• Hair loss

Some of the adverse effects of letrozole are more serious. Call your doctor right away or seek emergency medical help if you develop the following symptoms:

• Chest pain
• Difficulty breathing
• Allergic reactions with skin rash, hives, itching
• Unusual bleeding or bruising
• Right upper stomach pain
• Yellowing of the eyes or skin
• Flu-like symptoms
• Pain, warmth, heaviness in the lower leg
• Sudden weakness or numbness in an arm or leg
• Sudden problems with speech
• Severe headache

The above list may not include all the potential side effects of letrozole. Contact your healthcare provider if the side effects are unusual or severe or if they do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Letrozole (Femara) Overdose: In case of an overdose of letrozole, call your doctor immediately. You can also call the National Poison Control Center at 1-800-222-1222. Call 911 if someone has collapsed, is not responding, has stopped breathing, or has had a seizure.

Source: FDA