Bone Effects
Patients using Letroz may see a decrease in lumbar spine and hip bone
mineral density. The incidence of bone
fractures and thinning of bones has also observed with the combined therapy of tamoxifen and Letroz. It is advised to monitor bone mineral density.
Cholesterol Level
A very high level of
cholesterol in the blood has been observed with the combined use of Letroz and tamoxifen. Proper monitoring of the blood cholesterol level should be considered.
Liver Abnormality
Patients with liver damage are at an increased risk while using this medicine. Patients with scarring of the liver and severe liver damage experienced twice the exposure to Letroz. Therefore, a dose reduction is advised for such patients. The effect of liver damage on Letroz exposure in
cancer patients with raised bilirubin levels has not been evaluated.
Fatigue and Dizziness
Fatigue, drowsiness, and
dizziness have been seen with the use of Letroz. Take necessary precautions in such patients while driving or using machinery, until it is recognized how the patient responds to Letroz use.
Laboratory Test Abnormalities
Patients using Letroz may experience a moderate decrease in lymphocyte count and abnormally low levels of thrombocyte.
Fetal Poisoning
Letroz can induce harm to the unborn baby and should not be used in pregnant women. In post-marketing reports, the use of Letroz during
pregnancy resulted in problems of unintentional
abortions and existing birth defects. Pregnant women are advised of the possible risk to an unborn baby. Females of reproductive potential are encouraged to use effective
contraception during treatment with Letroz and at least for 3 weeks after the final dose.
Family History Problems
Patients with rare family history problems of severe lactase deficiency, galactose intolerance or improper absorption of glucose-galactose are at an increased risk when using this medicine. Use of Letroz is not recommended in such patients.
Tamoxifen, or other Antiestrogens
Use of Letroz with tamoxifen, other anti-estrogens or estrogen-containing medicines should abstain as these substances may reduce the drug action of Letroz.
Menopausal Status
Patients whose
menopausal status is not clear, follicle-stimulating
hormone, luteinizing hormone, and estradiol levels should be estimated before starting therapy with Letroz. Only women who have undergone a period of menopause endocrine status should take Letroz.