Pharm MD7 Flashcards
(16 cards)
1
Q
IV MgSO4
A
- prophylaxis and tx of eclamptic sz
- given prior to delivery d/t unpredictability of sz onset despite severity of dz
- MoA:
- cerebral vasodilation-> decr ischemia in an eclamptic event
- peripheral vasodilation-> decr BP in preeclampsia/eclampsia
- binds NMDA-R blocking entry of Ca2+ in synaptic cleft-> decr neurotransmission (CNS depression)
- also used as tocolytic to prevent pregnancy (smooth muscle relaxant, status asthmaticus?)
- also possibly used in arrhythmias, torsades
- AE: Mg toxicity-> hypotension, circulatory collapse, CNS & resp. depression
2
Q
Pitocin
A
synthetic form of oxytocin indicated for induction/strengthening of labor, postpartum hemorrhage
MoA:
via Gq protein-> incr IP3-> incr Ca2+-> incr muscle contraction:
- in uterus-> incr contractions for delivery
- in uterus s/p delivery-> compresses blood vessels-> decr hemorrhage
- in myoepithelium of mammary ducts-> incr milk ejection
AE: water intoxication (similar to ADH), tetanic uterine contractions, arrhythmias (maternal & fetal)
3
Q
PDE5 Inhibitors (Sildenafil/Viagra, Vardenafil/Levitra, Tadalafil/Cialis)
A
- indicated for erectile dysfunction (ED), causes erection following sexual stimulation
MoA:
- normally, parasympathetic stimulation causes endothelial release of NO-> activates guanylyl cyclase to convert GTP to cGMP-> activates PKG-> activates myosin light chain phosphatase (MLCP)-> dephosphorylates myosin light chains-> arterial smooth muscle relaxation-> incr blood flow to corpora cavernosa-> erection
- PDE5 breaks down cGMP
- inhibition of PDE5-> decr cGMP breakdown-> incr cGMP for vasodilation
- doesn’t work in the absence of sexual stimulation (required for NO release)
AE:
- CI for use along w/ nitrates-> severe hypotension
- very rarely, priapism
- Hot (flushing), Headache, Heartburn
4
Q
Clomiphene (Clomid), Gonadotropins
A
Clomiphene
- SERM, nonsteroidal for inducing ovulation in anovulatory pts, especially PCOS
- MoA: competitive antagonist of estradiol @ estrogen receptors in hypothalamus-> blocks negative feedback-> incr freq. & amplitude of GnRH pulses-> incr FSH & LH-> incr follicle development
- used on follicular phase 5th-9th days (5 day dosage cycle), usually inducing ovulation @ normal time of cycle
- only indicated in pts w/ normal HPG axis
- AEs: slight incr in multiple gestations (from 1% to 3-5%), hot flashes (d/t antiestrogenic effects), ovarian enlargement (weak estrogen agonist), visual disturbances
Gonadotropins
- injectable FSH w/ or w/o LH-> incr estrogen secretion and follicular maturation
- hCG is administered to induce ovulation
- used to tx infertility in pts refractory to Clomiphene (abnormal HPG axis)
- low estrogen levels = inadequate gonadotropin stim., high estrogen levels = incr risk of OHSS
- AEs: Ovarian Hyperstimulation Syndrome (OHSS): release of vasoactive contents from enlarged corpus luteum-> incr vascular permeability-> 3rd spacing of fluids-> hypovolemia, ascites, electrolyte abn, thromboembolism (d/t hemoconcentration & incr estrogen), ARDS
- incr incr risk of multiple gestations
5
Q
Leuprolide
A
- GnRH analog: agonist (pulsatile), antagonist (continuous)
- given IM or subQ for antagonistic effects
- MoA: (continuous) inhibits FSH & LH release-> decr testosterone (testes), estrogen (ovaries)-> tx of prostate cancer, endometriosis, uterine fibroids, precocious puberty
- may initially cause exacerbation/incr in FSH & LH (use antiandrogen during that time in prostate cancer tx), castrate condition in 1-2 wks
- (pulsatile) similar effects to GnRH-> incr FSH & LH-> tx of infertility
- AEs: sx of decr testosterone (decr libido, impotence, testicular atrophy), sx of decr estrogen (hot flashes, osteoporosis)
- Ovarian Hyperstimulation Syndrome (OHSS), rarely
6
Q
Bromocriptine
A
- ergot dopamine agonist
- Indicated for hyperprolactinemia (prolactinoma, hypo/hyperthyroid)
- MoA: hypothalamic dopamine naturally inhibits pituitary prolactin secretion
- Indicated for Parkinson’s Disease, NMS
- MoA: incr dopamine levels (decr in PD & w/ antipsychotic use)
7
Q
Indomethacin
A
NSAID, competitive (w/ AA), reversible inhibitor of COX-1 & 2
- used to close patent ductus arteriosus in preterm infants (inhibits formation of PGE1, which vasodilates)
- AEs: incr risk of GI AEs (bleeding, ulcers, perforation) d/t protective effects of COX-1 PGs on gastric mucosa, incr risk of renal ischemia (d/t PGs dilating afferent arteriole)
8
Q
Mifepristone/Misoprostol
A
- antiprogesterone used in combo w/ a PG (misoprostol = PGE1) for medically induced abortion
- Mifepristone used on own as postcoital contraceptive
- FDA approved for induced abortion = 7 weeks gestation
- Mifepristone competitively antagonizes progesterone @ it’s receptors leading to decr. maintenance of endometrium during pregnancy, also sensitizes myometrium to PGs, incr synthesis/decr breakdown of PGs
- PGs (e.g. misoprostol) given after mifepristone incr. uterine smooth muscle tone
- incr uterine activity 36-48 h after admin.
- confirmatory decr b-hCG (termination of pregnancy) usually in 10 d following admin
AE:
- cramping, incomplete abortion-> bleeding, failure to evacuate uterus-> f/u suction curettage
- also contains antiglucocorticoid activity (CI in pts who take glucocorticoids)
9
Q
Levonorgestrel
A
- Plan B (progestin) used as an OTC emergency postcoital contraceptive, Tx of menorrhagia
- effective if taken < 72 h after unprotected sex (doesn’t work if embryo already implanted) (96-98% clinical effectiveness)
MoA:
- Inhibit/delay ovulation
* progestins bind to progesterone receptors in hypothal.-> decr GnRH release-> blunting of LH surge-> prevents follicular maturation and ovulation (prevents in 70-80%) - disrupt fertilzation, embryo transport, implantation
* thicken cervical mucus (prevent sperm migration and fertilization), thins endometrium (preventing implantation)
AE:
- less n/v vs. Yuzpe (estrogen-progesterone combo)
10
Q
HTN Tx in Pregnancy
A
Labetalol
- nonselective B-blocker, 1st line tx of general & acute
- MoA: decr HR & contractility (B1), prevent renin stimulation (B1)
- AE: bronchospasm (B2), HF (B1)
Methyldopa
- formerly 1st line, less effective vs. labetalol
- MoA: stimulates central a2-> vasodilation
- AE: orthostatic hypotension
Hydralazine
- used in acute HTN
- MoA: incr cGMP-> vasodilation (aa > vv)-> decr afterload
- used along w/ labetalol to prevent reflex tachycardia
- AE: drug-induced lupus
Nifedipine
- Ca2+ blocker-> smooth muscle relaxation-> decr TPR, tocolytic (decr uterine contractions)
- AE: hypotension
*definitive tx = delivery of baby (removal of offending agent, placenta)
- if premature (< 37 wks), betamethasone (steroids) to promote fetal lung maturity
11
Q
Prostate Carcinoma Tx
A
Low Grade Dz
Older/decr life expectancy/cormobidities:
- active surveillance of DRE & PSA
- no overtreatment, but missed chance to treat & incr mortality
Younger/incr life expectancy (> 10 y):
- Radical prostatectomy:
- complete removal-> PSA 0 in 6 mo.
- immediate transient incontinence, impotence (neurologic), infertility
- Radiation:
- external beam or seeds
- incontinence, impotence over time (vascular), proctitis
High Grade Dz
- Medical Castration:
- GnRH agonist (Leuprolide), continuous-> downregulation of receptors on ant. pit.-> decr FSH, LH-> decr androgens-> decr tumor size
- antiandrogens (Flutamide) given in beginning of tx to prevent initial androgen exacerbation by GnRH agonists, but not very effective in tx alone
- AEs: gynecomastia, decr libido, bone & muscle mass, mood, fatigue
- orchiectomy
- Chemotherapy for androgen-resistant dz (low efficacy)
12
Q
BPH Tx
A
a-blockers
- a1 (terazosin) for use in HTN pts
- decr prostatic & bladder sphincter, vascular smooth muscle contraction-> incr urinary flow & decr BP
- AE: orthostatic hypotension (no reflex tachycardia d/t no a2 blockade)
- a1a (tamsulosin) for use in normotensive (only targets prostate & bladder)
5a-reductase inhibitor** **(Finasteride)
- prevent conversion of testosterone to DHT
- takes 6 mo. for effect
TURP
- surgical resection of transitional zone prostatic tissue
13
Q
Ampicillin
A
-aminopenicllin, extended spectrum penicillin, but still B-lactamase sensitive
Indications:
- in addition to penicillin’s Gram + coverage
- enterococcus, listeria
- Gram -, especially of the gut (e. coli, salmonella, shigella, proteus)
- HHELPSS (h influenzae, h pylori, e coli, listeria, proteus, salmonella, shigella)
MoA:
- B-lactam ring binds to PBP-> prevents 3rd/final step in bacterial cell wall synthesis-> bacterial lysis
AE:
- hypersensitivity (penicillin allergy), rash, pseudomembranous colitis, incr GI vs. amoxicillin
*can be used along with clavulanic acid (Augmentin) for coverage vs. beta-lactamase producing organisms
14
Q
Cefotaxime, Cefoxitin
A
Cefotaxime
- parental 3rd gen. cephalosporin
Indications:
- more Gram - coverage than earlier cephalosporins
- Tx of enteric Gram - meningitis (e. coli, neisseria)
- ceftriaxone not used in neonates d/t risk of kernicterus (displaces bilirubin from albumin)
MoA:
- beta lactam binds PBP-> inhibit 3rd/final step in bacterial cell wall synthesis-> bacterial lysis
- less susceptible to beta lactamases
AE:
- cross-reactivity w/ penicillins (hypersensitivity)
*organisms not covered by cephalosporins are LAME (listeria, atypicals, MRSA, enterococci)
*ceftaroline (5th gen.) vs. MRSA (Caroline beats MRSA)
Cefoxitin
- 2nd gen cephalosporin
- more Gram - vs. 1st gen.
- inducer of beta-lactamases
15
Q
Doxycycline
A
- tetracycline antibiotic
unique features vs. other tetracyclines:
- longer-acting (once-daily dosing)
- indicated for pts w/ poor renal function d/t fecal excretion (vs. renal for other tetracyclines)
MoA:
- binds 30s ribosomal subunit, prevents attachment of aminoacyl-tRNA to mRNA-> inhibition of bacterial protein synthesis (bacteriostatic)
Indications:
- nongonococcal urethritis & cervicitis (chlamydia)
- intracellular bugs like chlamydia and rickettsia
- acne (lipophilicity allows entry into cells)
- Borrelia (Lyme Dz)
AEs:
- discolored teeth, retarded bone growth in children
- GI distress, photosensitivity
Comments:
- avoid giving w/ divalent cations (Ca2+, Mg2+, Fe2+) (antacids, milk, iron) d/t decr. absorption from gut
Monocycline
- in general, less AEs vs. doxycycline
- more lipophilic, but also = more CNS penetration (CNS AEs e.g. dizziness)
- not water-soluble, cannot be used for urinary infxns
16
Q
Azoles (e.g. fluconazole)
A
- antifungal triazole
MoA:
- binds 14-alpha demethylase (CYP450 enzyme)-> prevention of conversion of lanosterol to ergosterol (component of fungal cell membrane)-> membrane instability/leakage of cellular contents
Indications:
- candida infections, prophylaxis of cryptococcal meningitis in AIDS pts
- local and mild systemic fungal infections
AE:
- CYP450 inhibitor (drug metabolism)
- ketoconazole (imidazole, older drug) can prevent testosterone synthesis (via 17, 20 desmolase)-> gynecomastia, can be used in tx of PCOS
