Endocrine Drugs - Gonadal Hormones And Inhibitors Flashcards
What are the clinical applications of ethinyl estradiol?
- Hypogonadism in girls and women.
- Oral hormonal contraceptive.
- Intractable dysmenorrhea or uterine bleeding.
- Parenteral contraceptive.
What are the pharmacokinetics of ethinyl estradiol?
- Oral/parenteral/transdermal administration.
- Metabolism relies on cytochrome P450 systems.
- Enterohepatic recirculation occurs.
What are the features of ethinyl estradiol’s moderate toxicity?
- Breakthrough bleeding
- Nausea
- Breast tenderness
What are the features of ethinyl estradiol’s serious toxicity?
- Thromboembolism
- Gallbladder disease
- Hypertriglyceridemia
- Migraine headache
- Hypertension
- Depression
What is the toxicity of ethinyl estradiol in post menopausal women?
- Breast cancer
2. Endometrial hyperplasia (unopposed estrogen)
What complication might follow if ethinyl estradiol is combined with a CYP450 inducer?
Can lead to breakthrough bleeding and reduced contraceptive efficacy.
What is the mestranol?
A prodrug that is converted to ethinyl estradiol, contained in some contraceptives.
What is the mechanism of action of norgestrel?
Activation of progesterone receptor leads to changes in the rates of transcription of progesterone-regulated genes.
What are the clinical applications of norgestrel?
- Oral hormonal contraceptive
- Parenteral contraceptive
- Post coital contraceptive
What are the pharmacokinetics of norgestrel?
- Oral/parenteral/transdermal administration.
- Metabolism relies on CYP450.
- Enterohepatic circulation.
What are the toxicities of norgestrel?
- Weight gain
2. Reversible decrease in bone mineral density (high doses).
Mention 2 progesterone derivatives.
- Medroxyprogesterone acetate
2. Megestrol acetate
Mention 2 older 19-nortestosterone derivatives.
- Norethindrone
2. Ethynodiol
Mention 4 newer 19-nortestosterone derivatives.
- Desogestrel
- Norelgestromin
- Norgestimate
- Etonogestrel
Mention a spironolactone derivative.
Drospirenone.
Mention a major selective estrogen receptor modulator (SERM).
Tamoxifen
What is the mechanism of action of tamoxifen?
- Estrogen antagonist actions in breast tissue and CNS.
2. Estrogen agonist effects in liver and bone.
What is the clinical application of tamoxifen?
Prevention and adjuvant treatment of hormone-responsive breast cancer.
How is tamoxifen administered?
Orally
What are the toxicities of tamoxifen?
- Hot flushes
- Thromboembolism
- Endometrial hyperplasia
Mention a similar drug to tamoxifen?
Toremifene
What is the mechanism of action of raloxifene?
Antagonist effects in breast, CNS, and endometrium and agonist effects in the liver.
What are the clinical applications of raloxifene?
Approved for osteoporosis and prevention of breast cancer in selected patients.
What is the mechanism of action of clomiphene?
Antagonist effect in pituitary increases gonadotropin secretion.
What is the clinical application of clomiphene?
Used for ovulation induction.
What is the mechanism of action of fulvestrant?
Estrogen receptor antagonist in all tissues.
What is the clinical application of fulvestrant?
Adjuvant treatment of hormone-responsive breast cancer that is resistant to first-line antiestrogen therapy.
How is fulvestrant administered?
IM
What are the toxicities of fulvestrant?
- Hot flushes
- Headache
- Injection site reactions
What is the mechanism of action of anastrozole?
Reduces estrogen synthesis by inhibiting aromatase enzyme.
What is the clinical application of anastrozole?
Adjuvant treatment of hormone-responsive breast cancer.
How is anastrozole administered?
Orally
What are the toxicities of anastrozole?
- Hot flushes
- Musculoskeletal disorders
- Reduced bone mineral density
- Joint symptoms (Arthralgias, arthritis, arthrosis, cervical spondylosis, osteoarthritis, and disk herniation)
Mention a drug similar to anastrozole?
Letrozole
Mention an irreversible aromatase inhibitor.
Exemestane
What is the mechanism of action of danazol?
Weak CYP450 inhibitor and partial agonist of progestin and androgen receptors.
What is the clinical application of danazol?
Endometriosis and fibrocystic breast disease.
How is danazol administered?
Orally
What are the toxicities of danazol?
- Acne
- Hirsutism
- Weight gain
- Menstrual disturbances
- Hepatic dysfunction
What is the mechanism of action of mifepristone?
Progestin and glucocorticoid receptor antagonist.
What is the clinical application of mifepristone?
Used in combination with a prostaglandin (misoprostol) for medical abortion.
How is mifepristone administered?
Orally
What are the toxicities of mifepristone?
- GI disturbances (mostly due to coadministration of misoprostol).
- Vaginal bleeding
- Atypical infection
What is the mechanism of action of testosterone?
Androgen receptor agonist
What are the clinical applications of testosterone?
- Male hypogonadism
2. Weight gain in patients with wasting syndromes
How is testosterone administered?
- Transdermal
- Buccal
- SC implant
What are the toxicities of testosterone?
In females –> virilization
In males –> high doses can cause gynecomastia, testicular shrinkage, infertility.
Mention 2 oral androgens.
- Fluoxymesterone
2. Methyltestosterone
What is the clinical use of testosterone esters?
Long-acting androgens for parenteral administration.
Mention 2 anabolic steroids.
- Oxandrolone
2. Nandrolone decanoate
What can anabolic steroids cause?
- Increased ratio of anabolic-to-androgenic activity in lab animals.
- Cholestatic jaundice
What is the mechanism of action of finasteride?
Inhibition of 5α-reductase that converts testosterone to dihydrotestosterone.
What is the clinical application of finasteride?
- BPH
2. Male-pattern hair loss
How is finasteride administered?
Orally
What are the toxicities of finasteride?
Rarely –> impotence and gynecomastia.
Mention a drug similar to finasteride.
Dutasteride
What is the mechanism of action of flutamide?
Competitive inhibition of androgen receptor.
What is the clinical application of flutamide?
Advanced prostate cancer.
How is flutamide administered?
Orally
What are the toxicities of flutamide?
- Gynecomastia
- Hot flushes
- Impotence
- Hepatotoxicity
Mention 2 drugs similar to flutamide, but with lower risk for hepatotoxicity.
- Bicalutamide
2. Nilutamide
What diuretic is also used for the treatment of hirsutism?
Spironolactone
What is the mechanism of action of ketoconazole?
Inhibition of CYP450 enzymes involved in androgen synthesis.
What is the clinical application of ketoconazole?
Advanced prostate cancer that is resistant to first-line antiandrogen drugs.
How is ketoconazole administered?
Orally
What are the toxicities of ketoconazole?
- Interferes with synthesis of other steroids.
2. Many drug interactions due to CYP450 inhibition.
What is the mechanism of action of ethinyl estradiol?
Activation of estrogen receptors leads to changes in the rates of transcription of estrogen-regulated genes.