Lesson

Oral contraceptives, or birth control pills, simulate a hormonal state that mimics pregnancy. If the human body thinks that it is pregnant, it will not ovulate and release an egg to be fertilized. These medications are 99% effective if taken exactly as prescribed at the same time every day. Oral contraceptives are available in four different categories: monophasic, biphasic, triphasic, and progestin-only. Monophasic oral contraceptives have fixed doses of progestin and estrogen in each tablet. Biphasic birth control pills have two phases of hormones in each monthly pack. The first phase contains fixed doses of a progestin and an estrogen, while the second phase provides an increased dose of progestin, but the same dose of estrogen. Similarly, triphasic oral contraceptives have three phases in each monthly prescription. Just like the others, the first phase provides fixed doses of a progestin and an estrogen. In the second phase, either one or both of the hormones increases in each tablet. In the third and final phase, either one or both of the hormones increases or decreases in each tablet. Finally, the progestin-only birth control pills only contain a progestin, such as norethindrone or norgestrel.

Oral methods are not the only way to administer contraceptives. Other alternatives include intrauterine devices, subcutaneous depo-formulated progestins, spermicidals, transdermal patches, and vaginal rings.

Loss of estrogen has multiple physiologic consequences, including vasomotor symptoms (hot flashes), accelerated bone loss, increased risk for CVD, and breast cancer.

The primary benefits of menopausal hormone therapy (HT) are suppression of vasomotor symptoms, prevention of urogenital atrophy, prevention of osteoporosis and related fractures, and prevention of colorectal cancer. Another benefit is improved quality of life. Data from HERS and HERS II indicate that HT does NOT protect against cardiovascular disease. Other benefits include a positive effect on wound healing, tooth retention, and glycemic control.

Minor adverse effects of HT include fluid retention, weight gain, and breast tenderness. As it relates to the cardiovascular system, data from WHI indicate that both ET and EPT increase risk for MI, stroke, pulmonary embolism, and DVT. There is also an increased risk for endometrial cancer (but only when used alone). There is a risk of breast cancer, ovarian cancer, gall bladder disease, and an increased risk for dementia and Alzheimer’s disease. It also may worsen urinary incontinence. The FDA ruled that all products intended for HT must carry strengthened warnings.

There are three FDA approved indications for HT: treatment of moderate to severe hot flashes associated with menopause, treatment of moderate to severe symptoms of loss of vulvar and vaginal muscle tone and vaginal dryness associated with menopause, and prevention of postmenopausal osteoporosis, or weakening of the bones. Every woman undergoing HT receives estrogen, and every woman with a uterus also receives a progestin. Several schedules of administration may be employed.

The overall strategy of drug therapy for female infertility is to produce a mature follicle of the ovaries, stimulate ovulation, provide sufficient production of cervical mucus, control endometriosis, and reduce excessive prolactin levels.

Clomiphene (Clomid, Milophene, Serophene) promotes follicular maturation and ovulation by blocking receptors for estrogen. This causes the pituitary to increase secretion of LH and FSH to stimulate the ovary to produce ovulation and follicular maturation. Common side effects include nausea, abdominal pain, bloating, hot flashes, and mammary pain. Some women even experience visual disturbances as well. Multiple births occur in 8% to 10% of women who choose this type of therapy. Ovarian hyperstimulation is rare. This drug should be avoided during pregnancy.

Menotropins (Pergonal, Repronex, Menopur, human menopausal gonadotropin) have equal amounts of LH and FSH and are used with HCG for follicular maturation and ovulation. Side effects include overstimulation of the ovaries. These medications also can cause spontaneous abortion or multiple births. Monitoring this kind of therapy includes checking ovarian responses to determine the timing of administration and measuring estrogen levels.

Follitropins, including urofollitropin (Metrodin, Fertinex, Bravelle), follitropin alfa (Gonal-F), and follitropin beta (Follistim), are preparations of FSH. It is used in women to act directly on the ovary to stimulate follicle maturation. The use in men has been approved for promoting spermatogenesis in males with primary or secondary hypogonadotropic hypogonadism.

Lutropin alfa (Luveris) is a recombinant form of LH and has been approved for combined use with follitropin alfa to promote follicular maturation in infertile, hypogonadotropic, and hypogonadal women with profound LH deficiency.

Human chorionic gonadotropin (hCG), like LH, promotes follicular maturation and induces ovulation. Adverse effects include ovarian hyperstimulation syndrome requiring hospitalization and discontinuation of HCG, rupture of ovarian cysts, multiple births, edema, pain at injection site, and CNS disturbances.

Choriogonadotropin alfa (Ovidrel) is a form of hCG produced by recombinant DNA technology.

Gonadotropin-releasing hormone antagonists (GnRH) can be used to prevent a premature surge of endogenous LH in women undergoing controlled ovarian stimulation.

Two dopamine agonists, cabergoline (Dostinex) and bromocriptine (Parlodel), are approved for hyperprolactinemia. Cabergoline is better tolerated and is more convenient than bromocriptine is.

As a GnRH agonist, Leuprolide (Lupron Depot) is indicated for uterine fibroids, central precocious puberty, and advanced prostate cancer; endometriosis; and suppressed endometriosis by indirectly suppressing ovarian hormone production. Common adverse effects are hot flashes, vaginal dryness, decreased libido, mood changes, and headache. The most concerning adverse effect is bone loss. The drug is given IM once a month, or every three months.

Oxytocin (Pitocin) is used for induction of labor. Oxytocin is a hormone produced by the posterior pituitary, which promotes uterine contraction during parturition and stimulates mild-ejection reflex. Physiologic and pharmacologic effects include uterine stimulation, milk ejection, and water retention. Pharmacokinetics include IV or IM and intranasal for promoting milk production, short half-life (12 to 17 minutes) with hepatic metabolism, and renal excretion. Improper use can be hazardous (as it can cause uterine rupture). Water intoxication is also possible due to antidiuretic effect.

Carboprost Tromethamine is used to control postpartum hemorrhage. Adverse effects include GI disturbances, fever, and vasoconstriction, as well as constriction of the bronchi. There is a risk of hypertension and impairment of respiration.

Reproduced digitally Turley, Susan M., Understanding Pharmacology For Health Professionals, 5th ed., (C)2016. Reprinted by permission of Pearson Education, Inc. New York, New York.