Pharm Quiz 2 Flashcards
Amoxicillin/cephalosporin
a. Beta-lactam
b. MoA – inhibits penicillin binding protein transpeptidase activity
i. Blocks the cross linking of peptidoglycans
c. Side effects
i. Diarrhea
1. Changes bacterial gut flora
ii. Cephalosporin and ampicillin
1. Elevation of liver enzymes
2. Cholestatic stricture -> jaundice
Gentamycin
a. Aminoglycoside
b. MoA – inhibit bacterial protein synthesis by binding to 30S subunit on ribosomes
i. Tetracyclines also do this (bacteriostatic)
c. Bacteriocidal
d. Useful against gm negatives
e. No anti-anareobic activity b/c requires oxygen for uptake
f. Toxicity
i. Nephrotoxic
ii. Ototoxic – hearing loss and tinnitus
1. Dose dependent
TMP-SMX (bactrim)
a. Trimethoprim
i. Inhibits dihydrofolate reductase
1. Blocks conversion of DHF -> THF
2. Decreased bacterial DNA synthesis
3. Bacteriostatic when used alone
ii. Toxicities
1. BM suppression
a. Worse in ppl w/ folic acid def
b. Leads to leukopenia, megaloblastic anemia, thrombocytopenia and neutropenia
2. Interferes w/ Cr and K clearance
3. Stones???
b. Sulfamethoxazole
i. Inhibits DHPS (dihydropteroate synthetase)
1. Converts PABA -> dihydropteroate which is converted into DHF
ii. Bacteriostatic by itself
c. Using both together is can be cidal or static depending on concentration
i. Synergistic effect
ii. TMP-SMX is useful for UTI’s, some MRSA infections, Listeria, Stenotrophomonas, Shigella, Salmonella, Pneumocystis jirovecii
d. Toxicities
i. Porphyria (sulfonamides are contraindicated in these disorders)
ii. Toxic epidermal necrolysis (Stevens Johnson syndrome)
iii. Kernicterus
iv. Hemolysis in G6PD pts
v. Nephrotoxicity
1. Crystalluria -> tx w/ bicarb
2. Allergic nephritis
vi. Photosensitivity
Ciprofloxacin
a. Fluoroquinolones
b. MoA – enter cell via membrane porins and inhibit DNA gyrase (topoisomerase II) and topoisomerase IV
c. Bacteriocidal
d. Good for gram negative and positive bacteria
i. Gm neg rods of urinary and GI tracts
1. Pseudomonas
ii. Neisseria
iii. Some gm positive
e. Toxicities
i. Spontaneous tendon rupture
ii. Cartilage injury in neonates if given to pregnant women
iii. Myalgias in kids
iv. Granulomatous interstitial nephritis
v. Phototoxicity
f. 2nd line for UTI
Nitrofurantoin
a. Usefulness limited to lower UTIs
b. Bactericidal
c. Gm pos and gm neg
i. NOT good for P. aeruginosa and Proteus
d. Mech unclear
i. Intermediates play a role -> disrupt DNA and RNA synth, proteins and metabolic processes
e. Side effect
i. Anorexia
ii. Nausea
iii. Vomiting
iv. Uncommon
1. Rashes, pulmonary infiltration and fibrosis
Amphotericin B
a. MoA – bind ergosterol and create pores in fungal cell membrane
