Antibiotics

Question 1

Penicillin G and V

Answer 1

MOA: Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units.

Use: gram (+) organisms and syphilis

Toxicity: Hypersensitivity, hemolytic anemia

Question 2

Methicillin, Nafcillin, Dicloxacillin

Answer 2

MOA: Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units. Penicillinase resistant

Use: Staph aureus except MRSA

Toxicity: Hypersensitivity, Nephritis (methicillin)

Question 3

Ampicillin, Amoxicillin

Answer 3

MOA:Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units. Combined with clavulanic acid.

Use: H. flu, E. coli, Listeria, Proteus, Salmonella, Shigella, enterococci

Toxicity: pseudomembranous colitis, rash (ampicillin)

Question 4

Ticarcillin, Carbenicillin, Piperacillin

Answer 4

MOA: Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units. Used with Clavulanic Acid.

Use: Pseudomonas, gram (-) rods

Toxicity: hypersensitivity reactions

Question 5

Clavulanic Acid, Sulbactam, Tazobactam

Answer 5

Beta Lactamase Inhibitors

Question 6

Cefazolin, Cephalexin

Answer 6

MOA: 1st gen cephalosporin, Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units.

Use: Proteus, E. coli, Klebsiella pneumoniae

Toxicity: vit. K def., nephrotoxicity increased with aminoglycosides

Question 7

Cefoxitin, cefaclor, cefuroxime

Answer 7

MOA: 2nd gen cephalosporin, Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units.

Use: Proteus, E. coli, Klebsiella, H. flu, Enterobacter a.

Toxicity: vit. K def., nephrotoxicity increased with aminoglycosides

Question 8

Ceftriaxone, Cefotaxime, ceftazidime

Answer 8

MOA: 3rd gen cephalosporin, Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units.

Use: Serious gram (-) infections

• Ceftriaxone: meningitis gonorrhea
• Ceftazidime: Pseudomonas

Toxicity: vit. K def., nephrotoxicity increased with aminoglycosides

Question 9

Cefepime

Answer 9

MOA: 4th gen cephalosporin, Bind penicillin binding proteins preventing cross linking of peptidoglycan wall units.

Use: Pseudomonas and Gram (+)

Toxicity: vit. K def., nephrotoxicity increased with aminoglycosides

Question 10

Aztreonam

Answer 10

MOA: monobactam, resistant to beta lactamase. Inhibits PBP3, synergistic with aminoglycosides

Use: gram (-) rods only

• patients w/ penicillin allergy
• patients with renal insufficiency that can’t take aminoglycosides

Toxicity: none really

Question 11

Imipenem/Cilastatin

Answer 11

MOA: Imipenem- beta lactam
Cilastatin- inhibits renal dehydropeptidase I
-the combo increases half life of the drug regimen

Use: anaerobes, gram (+) cocci, gram (-) rods

Toxicity: GI distress, rash, seizures

Question 12

Vancomycin

Answer 12

MOA: binds D-ala D-ala preventing cell wall fomraiton

Use: Gram (+) only
-MRSA and C. diff

Toxicty: Red Man Syndrome, Nephrotoxicity, Ototoxicity, Thrombophlebitis

Question 13

Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin

Answer 13

MOA: aminoglycosides, Bind 30S subunit preventing initiation complex formation. Require O2 for uptake

Use: severe Gram (-) rods
-Neomycin: bowel surgery

Toxicity: nephrotoxicity (especially w/ cephalosporins), Ototoxicity (w/ loop diuretics), Teratogenic

Question 14

Tetracycline, Doxycycline, Demeclocycline, minocycline

Answer 14

MOA: bind 30S preventing tRNA attachment, divalent cations inhibit absorption, doxy used in renal failure

Use: Borrelia b., M. pneumoniae, Rickettsia, Chlamydia

Toxicity: Disolored teeth, impaired bone growth in kids, Teratogenic, photosensitivity

Question 15

Erythromycin, Azithromycin, Clarithromycin

Answer 15

MOA: macrolides, prevent translocation by binding 50S subunit

Use: Atypical pneumonia (Mycoplasma, Chlamydia, Legionella)

Toxicity: Prolonged QT, GI discomfort, hepatitis, rashes

Question 16

Chloramphenicol

Answer 16

MOA: blocks peptide bond formation at 50S

Use: Meningitis (H. flu, Neisseria, Strep pneumo)

Toxicity: anemia, gray baby syndrome

Question 17

Clindamycin

Answer 17

MOA: blocks transpeptidation at 50S

Use: anaerobic pneumonia (bacteroides, clostridium)

Toxicity: pseudomembranous colitis

Question 18

Sulfamethoxazole, Sulfisoxazole, Sulfadiazine

Answer 18

MOA: inhibit dihydropterate synthase in folic acid metabolism

Use: Nocardia, Chlamydia, simple UTI

Toxicity: G6PD def. anemia, nephrotoxicity, kernicterus

Question 19

Trimethoprim

Answer 19

MOA: inhibits dihydrofolate reductase in folate metabolism

Use: UTIs, shigella, salmonella, Pneumocystis jiroveci

Toxicity: megaloblastic anemia, leukopenia, granulocytopenia

Question 20

Ciprofloxacin, Norfloxacin, Levofloxacin

Answer 20

MOA: Fluoroquinolones, inhibit DNA gyrase (topoisomerase II), not taken with antacids

Use: urinary and GI gram (-) rods

Toxicity: Tendon rupture in elderly, cartilage damage to fetus

Question 21

Metronidazole

Answer 21

MOA: makes free radical metabolites in bacterial cell that damage DNA, antiprotozoal

Use: Diardia, Entamoeba, Trichomonas, Darnerella, Anaerobes

Toxicity: disulfiram reaction with alcohol

Question 22

Isoniazid

Answer 22

MOA: decreased mycolic acid synthesiss (catalase peroxidase)

Use: TB prophylaxis and in RIPE regimen

Toxicity: neurotoxicty (supplement with B6), hepatotoxicity, lupus

Question 23

Rifampin

Answer 23

MOA: inhibits DNA-dependent RNAP

Use: TB, leprosy (prevents dapsone resistance)

Toxicity: orange body fluid, mild hepatotoxicity

Question 24

Pyrazinamide

Answer 24

MOA: unknown

Use: TB

Toxicity: hyperuricemia, hepatotoxicity

Question 25

Ethambutol

Answer 25

MOA: decreased carb polymerization of cell wall blocking arabinosyltransferase

Use: TB

Toxicity: red/green color blindness (optic neuropathy)

Question 26

Prophylaxis for Mycobacterium avium complex

Answer 26

Azithromycin

Question 27

Prophylaxis for Pneumocystis j.

Answer 27

TMP-SMX