estradiol, Alora; Climara; Delestrogen; Depo-Estradiol; Divigel; Elestrin; Estrace; and Others (cont.)
Eni Williams, PharmD, PhD
Eni Williams, PharmD, PhD
Dr. Eni Williams graduated from Creighton University in 1988 with a B.S. degree in pharmacy and a Doctor of Pharmacy from Howard University in 1994. She also obtained a Ph.D. in Public Policy in 2009 at the University of Maryland, Baltimore County.
Medical and Pharmacy Editor:
Rifampin, barbiturates, carbamazepine (Tegretol), griseofulvin, phenytoin (Dilantin), primidone and St. John's wort preparations can all increase the elimination of estrogen by enhancing the liver's ability to metabolize it. Concurrent use may result in reduction of the beneficial effects of estrogens. On the other hand, drugs such as erythromycin, clarithromycin, ketoconazole (Nizoral, Extina, Xolegel, Kuric), itraconazole (Sporanox), ritonavir (Norvir) and grapefruit juice can decrease the liver's ability to metabolize and eliminate estrogens and may increase the side effects of estrogen.
Estrogens may increase the levels and effects of exogenous corticosteroids (corticosteroids used as drugs that are not produced by the body), ropinirole (Requip, Requip XL), tipranavir (Aptivus) and medications that contain theophylline (Elixophyllin, Theo-24, Theochron).
Estrogens may reduce the levels and the effects of anastrozole (Arimidex), aripiprazole (Abilify), axitinib (Inlyta), hyaluronidase (Amphadase, Hylenex, Vitrase), saxagliptin (Onglyza), somatropin (Genotropin, Humatrope, Norditropen Flexpro etc.), ibrutinib (Imbruvica), and ursodiol (Actigall, Urso 250, Urso Forte).
Estrogen levels and effects may be decreased by dabrafenib (Tafinlar), deferasirox (Exjade), peginterferon Alfa-2b (Peg-Intron, Peg-Intron Redipen, Peg-Intron Redipen Pak 4 and Sylatron), P-glycoprotein inducers, tocilizumab (Actemra) and herbs that belong to a class of medications called CYP3A4 inducers. herbs with contents similar to estrogens may increase the side effects of estrogens.
Estrogen levels and effects may be increased by dehydroepiandrosterone, P-glycoprotein inhibitors, nonsteroidal anti-inflammatory drugs called COX-2 inhibitors such as celecoxib (Celebrex) and ascorbic acid (vitamin C).
PREGNANCY: Estrogens should not be used during pregnancy due to an increased risk of fetal abnormalities.
NURSING MOTHERS: Estrogens are secreted in milk and cause unpredictable effects in the infant. Estrogens generally should not be used by women if they are breastfeeding.
SIDE EFFECTS: Among the most common endocrine side effects are break-through bleeding or spotting, loss of periods or excessively prolonged periods, breast pain, breast enlargement, and changes in sexuality (increase or decrease in libido). Abdominal pain may indicate the development of gallstones or occasionally hepatitis. Migraine headaches have been associated with estrogen therapy. Estrogens can cause sodium and fluid retention leading to edema. Melasma, tan or brown patches, may develop on the forehead, cheeks, or temples. These may persist even after the estrogen is stopped. Conjugated estrogens may cause an increase in the curvature of the cornea. Patients with contact lenses may develop intolerance to their lenses.
Blood clots are an occasional but serious adverse effect and are dose-related. (The higher the dose of estradiol, the more likely blood clots are to form.) Cigarette smokers are at a higher risk for clots, and, therefore, patients requiring estrogen therapy are strongly encouraged to quit smoking.
Estrogens can increase the risk of endometrial cancer. This risk may be decreased if estrogens are combined with progestin. Some people also have a higher chance of developing breast cancer while taking estrogens. Sometimes people who have breast cancer when they are taking estrogens may have increased calcium in the blood. If this happens, the estrogen should be stopped.
Reference: FDA Prescribing Information
Last Editorial Review: 1/22/2014
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