Tamoxifen side effects

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Side effects

General

Patients with metastatic breast cancer

Patients with soft tissue disease

Male patients with breast cancer

Other adverse reactions

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General

Adverse reactions to Tamoxifen are relatively mild and rarely severe enough to require discontinuation of treatment in breast cancer patients. Continued clinical studies have resulted in further information which better indicates the incidence of adverse reactions with Tamoxifen as compared to placebo. Return to top

Patients with metastatic breast cancer

In patients treated with Tamoxifen for metastatic breast cancer, the most frequent adverse reaction to Tamoxifen is hot flashes. Increased bone and tumor pain and, also, local disease flare have occurred, which are sometimes associated with a good tumor response. Return to top

Patients with soft tissue disease

Patients with soft tissue disease may have sudden increases in the size of preexisting lesions, sometimes associated with marked erythema within and surrounding the lesions and/or the development of new lesions. Return to top

Male patients with breast cancer

Tamoxifen is well tolerated in males with breast cancer. Reports from the literature and case reports suggest that the safety profile of Tamoxifen in males is similar to that seen in women. Loss of libido and impotence have resulted in discontinuation of Tamoxifen therapy in male patients. Also, in oligospermic males treated with Tamoxifen, LH, FSH, testosterone and estrogen levels were elevated. No significant clinical changes were reported. Return to top

Other adverse reactions

Other adverse reactions which are seen infrequently are hypercalcemia, peripheral edema, distaste for food, pruritus vulvae, depression, dizziness, light-headedness, headache, hair thinning and/or partial hair loss, and vaginal dryness.
Less frequently reported adverse reactions are vaginal bleeding, vaginal discharge, menstrual irregularities, skin rash and headaches. Usually these have not been of sufficient severity to require dosage reduction or discontinuation of treatment. Very rare reports of erythema multiforme, Stevens-Johnson syndrome, bullous pemphigoid, interstitial pneumonitis, and rare reports of hypersensitivity reactions including angioedema have been reported with Tamoxifen therapy. In some of these cases, the time to onset was more than one year. Rarely, elevation of serum triglyceride levels, in some cases with pancreatitis, may be associated with the use of Tamoxifen. Return to top

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The content of this page is taken from the FDA package insert for this drug and should not be edited.