Megestrol acetate (MGA), sold under the brand name Megace among others, is a progestin medication which is used mainly as an appetite stimulant to treat wasting syndromes such as cachexia. It is also used to treat breast cancer and endometrial cancer, and has been used in birth control. MGA is generally formulated alone, although it has been combined with estrogens in birth control formulations. It is usually taken by mouth.Side effects of MGA include increased appetite, weight gain, vaginal bleeding, nausea, edema, low sex hormone levels, sexual dysfunction, osteoporosis, cardiovascular complications, glucocorticoid effects, and others. MGA is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has weak partial androgenic activity, weak glucocorticoid activity, and no other important hormonal activity. Due to its progestogenic activity, MGA has antigonadotropic effects. The mechanism of action of the appetite stimulant effects of MGA is unknown.MGA was discovered in 1959 and was introduced for medical use, specifically in birth control pills, in 1963. It may be considered a "first-generation" progestin. The medication was withdrawn in some countries in 1970 due to concerns about mammary toxicity observed in dogs, but this turned out not to apply to humans. MGA was approved for the treatment of endometrial cancer in 1971 and wasting syndromes in 1993. It is marketed widely throughout the world.
Primary dysmenorrhea is when there is no underlying cause that is identified, and secondary dysmenorrhea is when the menstrual pain is caused by other conditions such as endometriosis, fibroids, or infection. Diagnosis of menstrual disorders
Diagnosis begins with an in-depth medical history and physical exam, including a pelvic exam and sometimes a Pap smear.Additional testing may include but are not limited to blood tests, hormonal tests, ultrasound, gynecologic ultrasound, magnetic resonance imaging (MRI), hysteroscopy, laparoscopy, endometrial biopsy, and dilation and curettage (D&C). Treatment of menstrual disorders
Premenstrual syndrome and premenstrual dysphoric disorder
Due to the unclear etiology of premenstrual syndrome and premenstrual dysphoric disorder, symptom relief is the primary goal of treatment. Selective serotonin reuptake inhibitors and spironolactone decrease physical and psychological symptoms associated with premenstrual syndrome. Oral contraceptives may ameliorate physical symptoms of breast tenderness and bloating. Ovarian suppression treatment with gonadotropin-releasing hormone agonist as an off-label use may reduce symptoms but have adverse side effects including decreased bone density. Other less commonly use medications such as alprazolam may reduce anxiety symptoms but has potential for dependence, tolerance, and abuse. Pyridoxine, a form of vitamin B6, may be used as a dietary supplement to relieve overall symptoms. Amenorrhea
Successful treatment varies depending on the diagnosis of amenorrhea. In patients with functional hypothalamic amenorrhea due to physical or psychological stress, non-pharmacological options include weight gain, resolution of emotional issues, or decreased intensity of exercise. Patients experiencing amenorrhea due to hypothyroidism may be started with thyroid replacement therapy. Dopamine agonists such as bromocriptine are used in patients with pituitary adenomas.