Estrogen administration leads to increased thyroid-binding globulin (TBG) levels. Patients with normal thyroid function can compensate for the increased TBG by making more thyroid hormone, thus maintaining free T4 and T3 serum concentrations in the normal range. Patients dependent on thyroid hormone replacement therapy who are also receiving estrogens may require increased doses of their thyroid-replacement therapy. These patients should have their thyroid function monitored in order to maintain an acceptable range.
6. Fluid retention
Estrogens may cause some degree of fluid retention. Patients who have conditions that might be influenced by this factor, such as a cardiac or renal dysfunction, warrant careful observation when estrogens are prescribed.
7. Hypocalcemia
Estrogens should be used with caution in individuals with severe hypocalcemia.
8. Exacerbation of endometriosis
Endometriosis may be exacerbated with administration of estrogens. A few cases of malignant transformation of residual endometrial implants have been reported in women treated post-hysterectomy with estrogen alone therapy. For patients known to have residual endometriosis post-hysterectomy, the addition of progestin should be considered.
9. Exacerbation of other conditions
Estrogens may cause an exacerbation of asthma, diabetes mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and hepatic hemangiomas and should be used with caution in women with these conditions.
10. Photosensitivity/Photoallergy
Increased sensitivity to direct exposure to the sun on areas of EstroGel application has not been eva luated.
11. Effect of sunscreen application
The effects of concomitant application of EstroGel and a sunscreen lotion have not been eva luated.
12. Alcohol-based gels are flammable.
Avoid fire, flame, or smoking until the gel has dried.
B. Patient Information
Physicians are advised to discuss the PATIENT INFORMATION leaflet with patients for whom they prescribe EstroGel.
C. Laboratory Tests
Serum follicle stimulating hormone and estradiol levels have not been shown to be useful in the management of moderate to severe vasomotor symptoms and moderate to severe symptoms of vulvar and vaginal atrophy.
D. Drug and Laboratory Test Interactions
Accelerated prothrombin time, partial thromboplastin time, and platelet aggregation time; increased platelet count; increased factors II, VII antigen, VIII antigen, VIII coagulant activity, IX, X, XII, VII-X complex, II-VII-X complex, and beta-thromboglobulin; decreased levels of anti-factor Xa and antithrombin III, decreased antithrombin III activity; increased levels of fibrinogen and fibrinogen activity; increased plasminogen antigen and activity.
Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid hormone levels, as measured by protein-bound iodine (PBI), T4 levels (by column or by radioimmunoassay) or T3 levels by radioimmunoassay. T3 resin uptake is decreased, reflecting the elevated TBG. Free T4 and T3 concentrations are unaltered. Patients on thyroid-replacement therapy may require higher doses of thyroid hormone.
Other binding proteins may be elevated in serum (Corticosteroid-binding globulin [CBG], sex hormone-binding globulin [SHBG]), leading to increased total circulating corticosteroids and sex steroids, respectively. Free hormone concentrations may be decreased. Oth |
