Flashcards in 5b pharmakology Oral contraception (synthetic progestins, estrogen)Terbutaline, ritodrineDanazolTestosterone, methyltestosterone Antiandrogens Tamsulosin Sildenafil, vardenafil, tadalafil Minoxidil Deck (27):
You have prescribed oral contraceptive pills to a 15-year-old patient. She wants to be a doctor and asks how the pills work. Answer her.
Estrogen/progestins inhibit luteinizing hormone and follicle-stimulating hormone, blocking the estrogen surge and thus ovulation
Aside from preventing ovulation, how else do oral contraceptive pills prevent pregnancy?
Progestins thicken the cervical mucus (prevents sperm from entering uterus) and inhibit endometrial proliferation (prevents implantation)
What are three contraindications for oral contraceptive pills?
Smokers aged > 35 years (due to increased risk of cardiovascular events), history of thromboembolism/stroke, & estrogen-dependent tumors
You give a woman in labor a ß2-agonist. Will this help her to be more comfortable?
Yes, as β2-agonists (terbutaline, ritodrine) relax the uterus and reduce contraction frequency during labor
A 30-year-old woman is taking danazol. Which two medical conditions warrant this treatment?
Endometriosis and hereditary angioedema
Your patient recently started taking danazol for endometriosis. She now complains of side effects. What might they be?
Weight gain, edema, acne, hirsutism, masculinization, also reduces high-density lipoprotein levels and causes hepatotoxicity
You counsel an endometriosis patient about a drug that may give her side effects of hirsutism. What is the mechanism of action of this drug?
Acts as a partial agonist at androgen receptors (this is danazol, a synthetic androgen)
Testosterone can be used to treat hormonal deficiencies. How does it work?
This androgen receptor agonist can be used in hypogonadism to help develop 2° sex characteristics, and can cause female masculinization
• A patient comes to the ED with severe burn injuries. How is testosterone useful for patients who have suffered from a burn?
Testosterone stimulates anabolism, which helps promote recovery from burns or other severe injuries
What genital exam finding would you expect in a male patient using exogenous testosterone? Why?
Testicular atrophy; exogenous testosterone blocks LH release, which decreases intratesticular testosterone, causing testicular atrophy
How would exogenous testosterone affect the height of a child that has not completed puberty?
This child may be shorter than expected because of premature closure of the epiphyseal plates
A patient on testosterone therapy comes in for a check-in. What lab is important to draw? What findings would you expect?
Check serum lipids; you would expect elevated low-density lipoprotein (LDL) and decreased high-density lipoprotein (HDL) levels
A 46-year-old man is taking finasteride to prevent male-pattern baldness. What is the mechanism of action of this medication?
Blocks the conversion of testosterone to the more potent dihydrotestosterone (finasteride is a 5α-reductase inhibitor)
A 66-year-old man has difficulty urinating, nocturia, and male-pattern baldness. Which antiandrogen may be useful for him?
Finasteride, a 5α-reductase inhibitor, is used to treat benign prostate hypertrophy and male-pattern baldness
What is the mechanism of action of flutamide?
It is a nonsteroidal competitive testosterone receptor antagonist
Name two drugs that function as antiandrogens as an additional effect from their interference with steroid synthesis and signaling.
Ketoconazole (inhibits 17,20-desmolase & steroid synthesis), & spironolactone (blocks steroid binding, 17,20-desmolase, & 17α-hydroxylase)
What two adverse effects are common to both ketoconazole and spironolactone?
Gynecomastia and amenorrhea
Which condition is flutamide used to treat?
Ketoconazole and spironolactone are used to prevent what conditions in women?
Hirsutism and androgenic symptoms in women with polycystic ovarian syndrome
An elderly man with benign prostatic hyperplasia (BPH) takes a drug that inhibits smooth muscle contraction. What drug class is this?
An α1-antagonist that inhibits smooth muscle contraction and thereby treats BPH (this is tamsulosin)
Why does tamsulosin relax the smooth muscles of the prostate but not the systemic vasculature?
It is selective for α1A,D-receptors found on the prostate, rather than the α1B-receptors on systemic vessels
A patient presents with symptoms of flushing, reflux, headache, and impaired blue-green vision. What drug has he likely ingested?
Sildenafil/vardenafil/taffrail (Hot and sweaty, but then Headache, Heartburn, Hypotension)
A man with severe hypertension now has life-threatening hypotension after taking sildenafil. What other medication is he likely taking?
Nitrates (concomitant use can precipitate life-threatening hypotension)
A man with erectile dysfunction is taking sildenafil. How does this medication increase penile blood flow and cause erection?
It inhibits PDE-5, which causes increased cGMP levels, resulting in smooth muscle relaxation in the corpus cavernosum
What is the primary clinical use of sildenafil, vardenafil, and tadalafil?
The treatment of erectile dysfunction (sildenafil, vardenafil, and tadalafil fill the penis)
Pilots, especially those flying at night, are not allowed to take PDE-5 inhibitors before or during the flight. Why might this be?
PDE-5 inhibitors (sildenafil, vardenafil, tadalafil) can cause blue-green vision impairment, which may make it harder to fly the plane