Estrogen formulations

Adverse effects include nausea, weight gain, breast tenderness, and breakthrough bleeding. Oral contraceptives have also been associated with an increased incidence of thromboembolic disease, particularly in women who use tobacco products or have other risk factors for thromboembolism. The development of these complications is significantly reduced when low-dose estrogen formulations of oral contraceptives are used.3... 

As of 1994, there were approximately 47 progestin-containing contraceptive dmg formulations sold in the United States for use as oral contraceptives (Table 3). In addition, there are three nonoral contraceptive formulations containing progestins ie, one injectable (Depo-Provera), one as an intrauterine device (lUD) (Progestasert), and one implantable (Norplant). Of the oral formulations, all but two also contain an estrogen component, ethynylestradiol. 

Several randomized trials have demonstrated that leuprolide and goserelin are effective agents when used alone in patients with advanced prostate cancer.19 Response rates around 80% have been reported, with a lower incidence of adverse effects compared with estrogens.19 There are no direct comparative trials of the currently available LHRH agonists or the dosage formulations, but a recent meta-analysis reported that there is no difference in efficacy or toxicity between leuprolide and goserelin. Therefore, the choice between the two usually is made based on cost and patient and physician preference for a dosing schedule. 

A wealth of epidemiological, clinical, and experimental studies link estrogens with cardiovascular disease (CVD). This evidence has promoted CVD as a key area within the extragenital effects of estrogens. The question is of interest because it directly affects the wide clinical use of estrogens as contraceptive agents or as principal constituents of hormonal therapy (HT) formulations in postmenopausal women. The significance of the subject is further reinforced by the relevance of CVD as a cause of mortality and morbidity in both women and men. 

Based on this concept of correlation between high replication rate/high persistent mutation risk, Pike et al. (1983) formulated the hypothesis of breast tissue age and developed a mathematical model to predict the effects of exposure to ovarian hormones. This model incorporates reproductive and endocrine items related to breast cancer and is able to predict the relative risk of individual situations with results that are very close to those observed in clinical trials. According to this hypothesis, both the years of exposure and the circulating serum levels of estrogens are associated to short-term breast cancer risk in postmenopausal women (Toniolo et al. 1995). 

C. Although progestin-only oral contraceptive formulations are available, the combination of estrogen and progestin is considered the safest and most desirable type. 

Diethylstilbestrol and hexestrol have been legally permitted for use as anabolics for quite some time in many countries, while the use of dienestrol, which is a metabolite of diethylstilbestrol, was restricted to illegal practice. Since all stilbene estrogens have high oral activity, both oral and parenteral formulations have been in use in catde and, to a lesser extent, in sheep and swine. 

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