Pharmacology 1: Block 3 Fertility

Estradiol

MOA: Most predominant estrogen in the human body; Indication/Why It's Given: Oral contraception; treatment of primary hypogonadism; treatment as hormone replacement therapy in post-menopausal women; Side Effects: Hypertension; thromboembolic disorders; gallbladder disease; giving estrogen alone as HRT increases risk of endometrial cancer

Norethidrone

MOA: Progesterone formulation; used to suppress ovarian function; Indication/Why It's Given: Oral contraception; treatment of dysmenorrhea, endometriosis, and uterine bleeding; used on hormone replacement therapy to prevent uterine hyperplasia and reduce risk of endometrial cancer; Side Effects: HRT should not be used in women with endometrial cancer or breast cancer history

Nuvaring

MOA: Progesterone/Estrogen combination; Estrogen – reduces FSH secretion; Progesterone – Inhibits the midcycle LH surge required for ovulation; Indication/Why It's Given: treatment of acne vulgaris; treatment of dysmenorrhea; Side Effects: Inserted for 3 weeks, removed for 1 week during which woman will have normal menstrual cycle

Nexplanon

MOA: Progesterone only; Indication/Why It's Given: Contraception; Side Effects: Implant approved up to 3 years; progestin-only contraceptives suited for women who smoke, are older and women whom estrogen is contraindicated

Yasmin

MOA: Progesterone/Estrogen combination; Estrogen – reduces FSH secretion; Progesterone – Inhibits the midcycle LH surge required for ovulation; Indication/Why It's Given: Oral contraception; treatment of acne vulgaris; treatment of dysmenorrhea; Side Effects: Drospirenone is an aldosterone antagonist with a weak antiandrogenic effect; beware of interactions with drugs that increase hepatic metabolism of OCP's

Paragard

MOA: Alters the viability and transport of both sperm and ovum, thus preventing pregnancy before fertilization; copper also damages ovum after fertilization but before implantation; Indication/Why It's Given: Contraception; Side Effects: Can be used for up to 10 years

Mirena

MOA: Progesterone; prevent pregnancy by producing localized effects on the endometrium; Indication/Why It's Given: Contraception; Side Effects: Can be used for up to 8 years

Plan B

MOA: Progesterone formulation; prevents fertilization by inhibition of ovulation and thickening of cervical mucous; unlikely to prevent the implantation of a fertilized egg; Indication/Why It's Given: Emergency contraception; Side Effects: Nausea and vomiting; first dose taken within 72 hours of intercourse and second dose taken 12 hours later

Ullipristal

MOA: Progestin agonist/antagonist; Indication/Why It's Given: Emergency contraception; Side Effects: Available by prescription only

Clomiphene

MOA: Weak estrogen agonist and moderate estrogen antagonist; blocks estrogen receptors (ER) in the hypothalamus and pituitary, preventing estrogen feedback inhibition on gonadotropin secretion; thus, it leads to increase in FSH and LH; Indication/Why It's Given: Treats anovulatory infertility; Side Effects: 5-7% of women treated with this have multiple births

Tamoxifen

MOA: Prodrug that is absorbed from the gut and converted to active metabolites; breast tissue – acts as estrogen receptor (ER) antagonist; Indication/Why It's Given: Used as prevention and treatment for breast cancer (tumor cells are estrogen receptor positive); Side Effects: Can lead to increased risk of endometrial cancer

Mifepristone

MOA: Glucocorticoid receptor antagonist AND progesterone receptor antagonist; causes endometrial degeneration, leading to detachment of the blastocyst; Indication/Why It's Given: Medical termination of pregnancy through 49 days gestation; Side Effects: Nausea and vomiting; after administration, followed up by giving a prostaglandin (misoprostol) 48 hours later to stimulate uterine contractions

Raloxifene

MOA: Estrogen agonist effect on bone; estrogen antagonist effect on breast; Indication/Why It's Given: Used for prevention of osteoporosis and reduction of risk of breast cancer

Finasteride

MOA: 5-alpha-reductase inhibitors; reduces DHT synthesis; Indication/Why It's Given: Treats symptomatic benign prostatic hypertrophy (BPH); used to treat male pattern baldness; Side Effects: Erectile dysfunction

Flutamide

MOA: Androgen receptor antagonist; Indication/Why It's Given: Treats inoperable prostate cancer alongside GnRH analogs