Chapter 34 Women's health drugs Flashcards
The development of the primary sex structures in the female reproductive system, initiation of reproductive functions (starting at puberty), and maintenance are controlled by?
pituitary gonadotropin hormones and the female sex steroid hormones—estrogens and progesterone.
Pituitary gonadotropins include?
follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which play a primary role in hormonal communication between the pituitary gland and the ovaries in the continuous regulation of the menstrual cycle from month to month.
Estrogens are also responsible for stimulating the development of?
secondary female sex characteristics and distribution of body fat and hair, creating optimal conditions for pregnancy in the endometrium just after ovulation, and promoting the start of menses.
The ovaries function both as endocrine glands and as reproductive glands. As reproductive glands, they?
produce mature ova within ovarian follicles, which are then ovulated or released into the space in the peritoneal cavity between the ovary and the fallopian tube.
Three major estrogens are synthesized in the ovaries: (1) estradiol (the principal estrogen), (2) esterone, and (3) estriol. Exogenous estrogens can be classified into two main groups:
(1) steroidal estrogens (e.g., conjugated estrogens, esterified estrogens, and estradiol)
(2) nonsteroidal estrogens (e.g., chlorotrianisene, dienestrol, and diethylstilbestrol [DES]).
Estradiol is the principal secretory product of the ovary and has several estrogenic effects. One of these effects is the regulation of gonadotropin (FSH and LH) secretion via negative feedback to the pituitary gland. Others include promotion of the development of women’s?
secondary sex characteristics, monthly endometrial growth, thickening of the vaginal mucosa, thinning of the cervical mucus, and growth of the ductal system of the breasts.
Progesterone is the principal secretory product of the corpus luteum and has progestational effects. This is required for?
endometrial egg implantation and maintenance of pregnancy.
Exogenous estrogenic drugs were developed because endogenous estrogens are inactive when taken orally. Synthetic drugs fall into two categories:
(1) steroidal and (2) nonsteroidal
Premarin is an estrogen mixture composed of?
conjugated estrogens, natural estrogen compounds equivalent to the average estrogen composition of the urine of pregnant mares.
-A nonanimal source is also available; Cenestin is conjugated estrogens from soy and yams.
Estrogens are used in the treatment or prevention of a variety of disorders that result primarily from?
estrogen deficiency. HRT to counter such estrogen deficiency is known for its benefits in treating menopausal symptoms.
Estrogens MOA
Binding of estrogen to intracellular estrogen receptors stimulates the synthesis of nucleic acids (DNA) and ribonucleic acids (RNA) and proteins
-estrogens required at puberty for development and maintenance of female reproductive system and development of female secondary sex characteristics (feminization)
Estrogens produce their effects in?
Estrogen-responsive tissues, which have a large number of estrogen receptors.
- These tissues include: female genital organs, breasts, pituitary gland, hypothalamus
- at time of puberty, production of estrogen increases greatly. This causes initiation of the menses, breast development, redistribution of body fat, softening of the skin, and other feminizing changes
Estrogens indications
Treatment or prevention of disorders that result from estrogen deficiency
- Atrophic vaginitis
- Hypogonadism
- Oral contraception (given with a progestin)
- Uterine bleeding
- Vasomotor spasms of menopause (“hot flashes”)
- Osteoporosis (treatment and prophylaxis)
- Breast or prostate cancer (palliative treatment)
- Ovarian failure or castration (or removal of ovaries)
Estrogens contraindications
Drug allergy Any estrogen-dependent cancer Undiagnosed abnormal vaginal bleeding Pregnancy Active thromboembolic disorder or history
Hormone replacement therapy (HRT) is used to?
Counter such estrogen deficiency and is most commonly known for its benefits in treating menopausal symptoms (hot flashes)
Estrogen contraindications
Drug allergy Any estrogen-dependent cancer Undiagnosed abnormal vaginal bleeding Pregnancy Active thromboembolic disorder or history (stroke or thrombophlebitis)
Estrogen adverse effects
- THROMBOEMBOLIC events: most serious
- Nausea: most common
- Hypertension, thrombophlebitis, edema
- Vomiting, diarrhea, constipation, abdominal pain
- May cause PHOTOSENSITIVITY, CHLOASMA (dermatologic effect)
- Amenorrhea, breakthrough uterine bleeding
- Tender breasts, fluid retention, headaches
Estrogen interactions
- Decrease the activity of the oral anticoagulants
- Decrease effect of rifampin
- St. John’s wort
- Tricyclic antidepressants
- Smoking
- Indicated for the treatment of many clinical conditions, primarily those resulting from estrogen deficiency
- Smallest dosage of estrogen that relieves the symptoms or prevents the condition is used
Estrogen therapy alone is associated with increased risk of ?
endometrial hyperplasia, a possible precursor of endometrial cancer. Adding progestin reduces the incidence.
Progestins include both natural and synthetic drugs. Progesterone is the most active natural progestational hormone; it is produced by the?
corpus luteum after each ovulation and during pregnancy by the placenta.
Progestins have a variety of uses, including treatment of?
Fibroids, uterine bleeding, primary and secondary amenorrhea and adjunctive and palliative treatment of some cancers and endometriosis
- can be used alone or in combination w/estrogens in prevention of conception
- preventing theatening miscarriage and alleviating symptoms of premenstrual syndrome
All progestin products produce the same physiologic
responses as those produced by progesterone itself, including?
induction of secretory changes in the endometrium, diminished endometrial tissue proliferation; increase in basal body temp.; thickening of vaginal mucosa; relaxation of uterine smooth muscle; stimulation of mammary alveolar tissue growth; feedback inhibition of the release of pituitary gonodotropins (FSH, LH); alterations in menstrual blood flow (especially in presence of estrogen)
Progestin: Megestrol (Megace) is commonly used as?
Adjunct therapy in Tx of breast and endometrial cancers
When estrogen replacement therapy is initiated after menopause?
Progestins are often included to decrease endometrial proliferation that can be caused by unopposed estrogen in women with an intact uterus
Formulations of progesteron itself are also used to treat?
Female infertility
The most serious undesirable effects of progestin use include?
liver dysfunction, thrombophlebitis, and thromboembolic
disorders such as pulmonary embolism.
Progestin interactions
Progestins may increase the effects of benzodiazepines and voriconazole
-Barbiturates, carbamazepine, phenytoin, rifampin, and St. John’s wort, which are all enzyme inducers, may DECREASE effectiveness of progestin
Decreased glucose tolerance may occur when progestins are taken with?
antidiabetic drugs