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99 terms

USMLE abx

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Ampicillin, amoxicillin (aminopenicillins)
Haemophilus influenzae, E. coli, Listeria monocytogenes, Proteus mirabilis, Salmonella, enterococci
Ampicillin, amoxicillin (aminopenicillins)
Hypersensitivity rxns, rash, pseudomembranous colitis
Methicillin, nafcillin, dicloxacillin (penicillinase-resistant penicillins)
S. aureus
Methicillin, nafcillin, dicloxacillin (penicillinase-resistant penicillins)
Hypersensitivity reactions, *interstitial nephritis
Ticarcillin, carbenicillin, piperacillin
Pseudomonas spp and GNR. Susceptible to penicillinase, use with clavulanic acid (beta-lactamase inhibitor)
Cefazolin, cephalexin
Proteus mirabilis, E. Coli, Klebsiella pneumoniae
Cefoxitin, cefaclor, cefuroxime
Haemophilus influenzae, Enterobacter aerogenes, Neisseria spp., Proteus mirabilis, E. coli, Klebsiella pneumoniae, Serratia marcescens
Ceftriaxone, cefotaxime, ceftazidime
Serious gram-negative infections resistant to other beta-lactams; meningitis (most penetrate BBB).
Ceftazidime
Pseudomonas
Ceftriaxone
Gonnorrhea
Cefepime
Increased activity against pseudomonas and gram-positive organisms
Cephalosporins
Hypersensitivity reactions. Cross-hypersensitivity with penicillins in 5-10%.
Cephalosporins
Increased nephrotoxicity of aminoglycosides
Cephalosporins
Disulfiram-like reaction with ethanol
Aztreonam
Synergistic with aminoglycosides
Aztreonam
No cross-allergenicity with penicillins. Binds PBP3
Aztreonam
Gram-negative rods - Klebsiella spp., Pseudomonas spp., Serratia spp.
Aztreonam
No activity against gram-positives or anaerobes
Aztreonam
For penicillin-allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides
Aztreonam
Usually non-toxic. Occassional GI upset.
Imipenem
Broad-spectrum, beta-lactamase-resistant carbapenem.
Imipenem
Always administered with cilastatin (inhibitor of renal dihydropeptidase I) to decrease inactivation in renal tubules.
Imipenem
Gram-positive cocci, gram-negative rods, and anaerobes.
Imipenem
Drug of choice for enterobacter
Imipenem
Significant side effects limit use to life-threatening infections, or after other drugs have failed.
Meropenem
Reduced risk of seizures. Stable to dihydropeptidase I
Imipenem
GI distress, skin rash, and CNS toxicity (seizures) at high plasma levels.
Vancomycin
Inhibits cell wall mucopeptide formation by binding D-ala D-ala portion of cell wall.
Vancomycin
Bactericidal. Resistance occurs with amino acid change of D-ala D-ala to D-ala D-lac
Vancomycin
Used for serious, gram-positive multidrug-resistant organisms, including S. aureus and Clostridium difficile
Vancomycin
Nephrotoxicity, Ototoxicity, Thrombophlebitis
Vancomycin
Diffuse flushing - preventable by pretreatment with antihistamines and slow infusion rate
Vancomycin
Generally well tolerated. Does not have many problems.
Aminoglycosides
30S inhibitor
Tetracyclines
30S inhibitor
Chloramphenicol
50S inhibitor
Clindamycin
50S inhibitor
Erythromycin
50S inhibitor
Lincomycin
50S inhibitor
Linezolid
50S inhibitor
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Bactericidal. Inhibit formation of initiation complex and cause misreading of mRNA.
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Require O2 for uptake. Ineffective against anaerobes.
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Severe gram-negative rod infections. Synergistic with beta-lactam antibiotics.
Neomycin
Bowel surgery
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Nephrotoxicity (especially when used with cephalosporins)
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Ototoxicity (especially when used with loop diuretics)
Aminoglycosides (Gentamycin, Neomycin, Amikacin, Tobramycin)
Teratogen
Tetracycline, doxycline, demeclocycline, minocycline
Bacteriostatic; bind to 30S and prevent attachment of aminoacyl-tRNA; limited CNS penetration.
Doxycycline
Fecally eliminated and cannot be used in patients with renal failure. Must NOT take with milk, antacids, or iron-containing preparations because divalent cations inhibit its absorption in the gut.
Tetracycline, doxycline, demeclocycline, minocycline
Vibrio cholera
Tetracycline, doxycline, demeclocycline, minocycline
Acne
Tetracycline, doxycline, demeclocycline, minocycline
Chlamydia
Tetracycline, doxycline, demeclocycline, minocycline
Ureaplasma
Tetracycline, doxycline, demeclocycline, minocycline
Urealyticum
Tetracycline, doxycline, demeclocycline, minocycline
Mycoplasma pneumoniae
Tetracycline, doxycline, demeclocycline, minocycline
Tularemia
Tetracycline, doxycline, demeclocycline, minocycline
H. pylori, Borrelia burgdorferi, Rickettsia
Tetracycline, doxycline, demeclocycline, minocycline
GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity.
Tetracycline, doxycline, demeclocycline, minocycline
Contraindicated in pregnancy
Macrolides (Erythromycin, azithromycin, clarithromycin)
Inhibit protein synthesis by blocking translocation. Bind to 23S rRNA of 50S ribosome. Bacteriostatic.
Macrolides (Erythromycin, azithromycin, clarithromycin)
URIs, pneumonias, STDs
Macrolides (Erythromycin, azithromycin, clarithromycin)
Gram-positive cocci (streptococcal infections in patients allergic to penicillin)
Macrolides (Erythromycin, azithromycin, clarithromycin)
Mycoplasma, legionella, Chlamydia, Neisseria
Macrolides (Erythromycin, azithromycin, clarithromycin)
Prolonged QT interval
Macrolides (Erythromycin, azithromycin, clarithromycin)
GI discomort (most common cause of noncompliance)
Macrolides (Erythromycin, azithromycin, clarithromycin)
Acute cholestatic hepatitis, eosinophilia, skin rashes.
Macrolides (Erythromycin, azithromycin, clarithromycin)
Increased serum concentration of theophyllines, oral anticoagulants
Chloramphenicol
Inhibits 50S peptidyltransferase activity. Bacteriostatic.
Chloramphenicol
Meningitis (Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae) Conservative use owing to toxicities.
Chloramphenicol
Anemia (does-dependent), aplastic anemia (dose independent)
Chloramphenicol
Gray baby syndrome (in premature infants because they lack liver UDP-glucuronyl transferase).
Clindamycin
Blocks peptide bond formation at 50S ribosomal subunit. Bacteriostatic.
Clindamycin
Treat anaerobic infections (e.g. Bacteroides fragilis, Clostridium perfringens)
Clindamycin
Pseudomembranous colitis, fever, diarrhea
Sulfonamides (Sulfamethoxazole SMX, sufisoxazole, sulfadiazine)
PABA antimetabolites inhibit dihydropteroate synthetase. Bacteriostatic.
Sulfonamides (Sulfamethoxazole SMX, sufisoxazole, sulfadiazine)
Gram-positive, gram-negative, Nocardia, Chlamydia.
Sulfonamides (Sulfamethoxazole SMX, sufisoxazole, sulfadiazine)
Simple UTI
Sulfonamides (Sulfamethoxazole SMX, sufisoxazole, sulfadiazine)
Hypersensitivity reactions, hemolysis of G6PD deficient
Sulfonamides (Sulfamethoxazole SMX, sufisoxazole, sulfadiazine)
Nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus in infants, displace other drugs from albumin (e.g. Warfarin)
Trimethoprim
Inhibits bacterial dihydrofolate reductase. Bacteriostatic.
Trimethoprim
Used in combination with sulfonamides causing sequential block of folate synthesis.
TMP-SMX
Recurrent UTIs, Shigella, Salmonella, Pneumocystis jiroveci pneumonia
Trimethoprim
Megaloblastic anemia, leukopenia, granulocytopenia (may alleviate with supplemental folinic acid)
Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid - a quinolone)
Inhibit DNA gyrase (topoisomerase II) Bactericidal
Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid - a quinolone)
Must not be taken with antacids
Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid - a quinolone)
Gram-negative rods of urinary and GI tracts (including pseudomonas), Neisseria, some gram-positive organisms.
Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid - a quinolone)
GI upset, superinfections, skin rashes, HA, dizziness.
Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid - a quinolone)
Contraindicated in pregnant women and children d/t cartilage damage. Tendonitis and tendon rupture in adults. Leg cramps and myalgias in kids.
Metronidazole
Forms toxic metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotazoal.
Metronidazole
Giardia
Metronidazole
Entamoeba
Metronidazole
Trichomonas
Metronidazole
Gardnerella vaginalis
Metronidazole
Anaerobes (Bacteroides, Clostridium)
Metronidazole
Used with bismuth and amoxicillin for "triple therapy" against H. pylori.
Metronidazole
Disulfiram-like reaction with alcohol; HA, metallic taste
Polyyxins (Polymyxin B, polymyxin E)
Bind to cell membranes of bacteria and disrupt their osmotic properties. Cationic, basic proteins that act like detergents.
Polyyxins (Polymyxin B, polymyxin E)
Resistant gram-negative infections
Polyyxins (Polymyxin B, polymyxin E)
Neurotoxicity, acute renal tubular necrosis