Letrozole Side Effects

Brand Names: Femara

Please note - some side effects for Letrozole may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Letrozole - for the Consumer

Letrozole

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Letrozole:

Back, leg, or arm pain; breast pain; constipation; cough; diarrhea; dizziness; headache; hot flashes; flushing; increased sweating; indigestion; joint or muscle pain; loss of appetite; mild swelling or fluid retention; nausea; night sweats; sleeplessness; stomach pain; tiredness; vaginal dryness or irritation; vomiting; weakness; weight gain or loss.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); calf pain or tenderness; chest pain; confusion; fever, chills, or sore throat; increased or painful urination; numbness of an arm or leg; one-sided weakness; severe or persistent bone pain; severe stomach pain; shortness of breath; sudden severe headache, vomiting, dizziness, or fainting; swelling of the ankles or feet; unexplained vaginal bleeding or discharge; vision or speech changes.

Side Effects by Body System

General

General side effects including fatigue (up to 8%), chest pain (up to 6%), peripheral edema (5%), asthenia (up to 5%), and increased weight (2%) have been reported.

Cardiovascular

Cardiovascular side effects including hypertension (up to 7%), palpitations, cardiac failure, arterial thrombosis, angioedema, and tachycardia have been reported.

Gastrointestinal

Gastrointestinal side effects including nausea (up to 15%), vomiting (7%), constipation (up to 7%), diarrhea (up to 6%), abdominal pain (up to 6%), anorexia (up to 5%), dyspepsia (up to 4%), and dryness of mucosa (including dry mouth) have been reported.

Other

In the adjuvant setting, an increase in total cholesterol in patients who had baseline values of total serum cholesterol within the normal range, and then subsequently had an increase in total serum cholesterol of 1.5 time the upper limit of normal (ULN) was 5.4% on letrozole versus 1.2% on tamoxifen. Lipid lowering medications were used by 18% of patients on letrozole and 12% on tamoxifen.

Other side effects including viral infection (up to 6%), dysesthesia, memory impairment, irritability, nervousness, stomatitis cancer pain, pyrexia, increased appetite and disturbances of taste and thirst have been reported.

Musculoskeletal

Musculoskeletal side effects including musculoskeletal effects in general (up to 22%) and arthralgia (up to 8%) have been reported.

In the extended adjuvant setting, preliminary results (median duration of follow-up was 20 months) from the bone sub-study (calcium 500 mg and vitamin D 400 international units per day mandatory; bisphosphonates not allowed) demonstrated that at two years the mean decrease compared to baseline in hip bone mass density in letrozole patients was 3% versus 0.4% for placebo. The mean decrease from baseline bone mass density results for the lumbar spine at two years was letrozole 4.6% decrease and placebo 2.2%. Consideration should be given to monitoring bone mass density.

Nervous system

Nervous system side effects including headache (up to 12%), somnolence (up to 3%), and dizziness (up to 5%) have been reported.

Respiratory

Respiratory side effects including dyspnea (up to 9%) and coughing (up to 6%) have been reported.

Dermatologic

Dermatologic side effects including hot flushes (up to 6%), rash (up to 5%), pruritus (up to 2%), urticaria, and dry skin have been reported.

Hepatic

Hepatic side effects including abnormal liver chemistries (3% in patients where it was not associated with a documented metastases) have been reported.

Hematologic

Hematologic side effects including leukopenia and a case of reversible pancytopenia have been reported.

Ocular

Ocular side effects including cataract, eye irritation, and cases of blurred vision have been reported.

Metabolic

Metabolic side effects including hypercholesterolemia (3%) have been reported.

Genitourinary

Genitourinary side effects including increased urinary frequency and vaginal discharge have been reported.

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