Antibacterial Drugs

Front 1

Penicillin

Mechanism
Clinical Use (bacteri____ for ____, ____, ___,and ____)
Toxicity (2)
Resistance

Back 1

Mech: bind penicillin-binding proteins (transpeptidases). Block transpeptidase cross-linking of peptidoglycan. Activate autolytic enzymes

Use: mostly used for gram positive organisms (S. pneumoniae, S. pyogenes, Actinomyces). Also used for N. meningitidis and Treponema pallidum.
Bactericidal for gram-positive cocci, gram-positive rods, gram negative cocci, and spirochetes.
Not penicillinase resistant

Toxicity: hypersensitivity reactions, hemolytic anemia

Resistance: beta-lactamases

Front 2

Oxacillin, nafcillin, dicloxacillin

Class/name of group
Mechanism (+ penicillinase sensitive/resistant)
Clinical Use (1)
Toxicity (2)

Back 2

group: penicillinase-resistant penicillins

Mech: bind penicillin-binding proteins (transpeptidases). Block transpeptidase cross-linking of peptidoglycan. Activate autolytic enzymes
Narrower spectrum than penicillin; penicillinase-resistant because bulky R group blocks access of beta lactamase to beta-lactam ring

Use: S. aureus (except MRSA; resistant because of altered penicillin-binding protein target site). No activity against gram negative infections

Tox: hypersensitivity reactions, interstitial nephritis

"use naf (nafcillin) for staph"

Front 3

Ampicillin, amoxicillin (aminopenicillins)

Mechanism (+ penicillinase sensitive/resistant)
Clinical Use (7 species)
Toxicity (3)
Resistance

Back 3

Mech: bind penicillin-binding proteins (transpeptidases). Block transpeptidase cross-linking of peptidoglycan. Activate autolytic enzymes.
Wider spectrum than penicillin; penicillinase sensitive. Combine with clavulanic acid to protect against beta-lactamase. AmOxacillin has greater Oral bioavailability than ampicillin

Use: extended spectrum penicillin - Haemophilus influenzae, E. coli, Listeria monocytogenes, Proteus mirabilis, Salmonella, Shigella, enterococci (HELPSS E)

Tox: hypersensitivity reactions, ampicillin rash, pseudomembranous colitis

Resistance: beta-lactamases cleave ring

Front 4

Ticarcillin, piperacillin

Name of group
Mechanism
Clinical Use (2 groups)
Toxicity (1)
Resistance

Back 4

Antipseudomonals

Mech: bind penicillin-binding proteins (transpeptidases). Block transpeptidase cross-linking of peptidoglycan. Activate autolytic enzymes.
Extended spectrum

Use: Pseudomonas spp. and gram-negative rods;

Toxicity: Hypersensitivity reactions

Resistance: susceptible to penicillinase; use with clavulanic acid

Front 5

Beta-lactamase inhibitors (3)

Back 5

Clavulanic acid, sulbactam, tazobactam.

Often added to penicillin antibiotics to protect the antibiotic from destruction by beta-lactamase

Front 6

Cephalosporins

Mechanism (+ cidal/static)

Organisms typically not covered (5 + exception)

Clinical Use
1st gen: 2 drugs, 1 group covered + 3 species + 1 special use
2nd gen: 3 drugs, 1 group covered + 6 species/genera
3rd gen: 3 drugs, 1 major use; specific uses for two of the drugs
4th gen: 1 drug, main use

Toxicity (3)

Back 6

Mechanism: Beta-lactam drugs that inhibit cell wall synthesis but are less susceptible to penicillinases.
Bactericidal

Not covered: Listeria, Atypicals (Chlamydia, Mycoplasma), MRSA, and Enterococci (LAME); exception: ceftraroline covers MRSA

Use:
1st gen - cefazolin, cephalexin:
gram-positive cocci,
Proteus mirabilis,
E. coli,
Klebsiella pneumoniae
Cefazolin used prior to surgery to prevent S. aureus wound infections
2nd gen - cefotoxitin, cefaclor, cefuroxime
gram-positive cocci
Proteus mirabilis,
E. coli,
Klebsiella pneumoniae
Haemophilus influenzae
Enterobacter aerogenes
Neisseria spp.
Serratia marcescens
3rd gen - ceftriaxone, cefotaxime, ceftazidime
serious gram-negative infections resistant to other beta-lactams
Ceftriaxone - meningitis and gonorrhea
Ceftazidime - Pseudomonas
4th gen: cefepime
increased activity against Pseudomonas and gram-positive organisms

Toxicity: Hypersensitivity reactions, vitamin K deficiency, increased nephrotoxicity of aminoglycosides. Low cross-reactivity with penicillins

Front 7

Aztreonam

Mechanism
Clinical Use (1 major group, two groups which it won't cover)
Toxicity (1)

Back 7

Mech: monobactam resistant to beta-lactamases. Prevents peptidoglycan cross-linking by binding to PBP3. Synergistic with aminoglycosides. No cross-allergenicity with penicillins

Use: gram-negative rods only - no activity against gram-positives or anaerobes. For penicillin-allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides

Tox: usually nontoxic; occasional GI upset

Front 8

Imipenem/cilastatin, meropenem

Mechanism
Clinical Use (3 major groups)
Toxicity (3)

Back 8

Mech: Transpeptidase inhibitor (like penicillins)
Imipenem is a broad-spectrum, beta-lactamase-resistant carbapenem. Always administered with cilastatin (inhibitor of renal dehydropeptidase I) to decrease inactivation of drug in renal tubules. (kill is 'lastin with cilastatin)

Use: Gram-positive cocci, gram negative rods, anaerobes. Wide spectrum, but significant side effects limit use to live-threatening infections or after other drugs have failed. Meropenem has a reduced risk of seizures and is stable without cilastatin

Tox: GI distress, skin rash, CNS toxicity (seizures) at high plasma levels

Front 9

Vancomycin

Mechanism
Clinical Use (1 major group, 3 notable spp.)
Toxicity (4)
Resistance

Back 9

Mech: inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors. (blocks PG chain elongation - upstream of cross-linking by transpeptidase)

Use: Gram positive only - serious, multidrug-resistant organisms, including MRSA, enterococci, and C. difficile

Tox: Nephrotoxicity, Ototoxicity, Thrombophlebitis, diffuse flushing - red man syndrome (can largely prevent by pretreatment with antihistamines and slow infusion rate). Well-tolerated in general - does NOT have many problems

Resistance: occurs with amino acid change of D-ala D-ala to D-ala D-lac.

Front 10

Aminoglycosides (5)

Mechanism
Clinical Use (1 group, 1 specific use, 1 group that is not covered)
Toxicity (4)
Resistance

Back 10

Names: Gentamicin, neomycin, amikacin, tobramycin, streptomycin

Mech: bactericidal; inhibit formation of initiation complex and cause misreading of mRNA. Also block translocation. Synergistic with beta-lactam antibiotics (beta-lactams increase permeability)

Use: Severe gram-negative rod infections. Neomycin for bowel surgery. Require O2 for uptake; therefore ineffective against anaerobes.

Tox: Nephrotoxicity (esp when used with cephalosporins), Neuromuscular blockade, Ototoxicity (esp. when used with loop diuretics). Teratogen

Resistance: Transferase enzymes that inactivate the drug by acetylation, phosphorylation, or adenylation

Front 11

Tetracyclines (4)

Mechanism (+ relevant metabolism + contraindication of concurrent drug use)
Clinical Use (4 spp.)
Toxicity
Resistance

Back 11

Tetracycline, doxycycline, demeclocycline, minocycline (demeclocycline is an ADH antaonist, acts as a diuretic in SIADH. rarely used as an antibiotic)

Mech: bacteriostatic; bind to 30S and prevent attachment of aminoacyl-tRNA; limited CNS penetration. Doxycycline is fecally eliminated and can be used in patients with renal failure. Do not take with milk, antacids, or iron-containing preparations because divalent cations inhibit its absorption in the gut.

Use: Borrelia burgdorferi, Mycoplasma pneumoniae, Rickettsia, Chlamydia (drug's ability to accumulate intracellularly makes it very effective against R and C)

Tox: GI distress, discoloration of teeth and inhibition of bone growth in children, photosensitivity. Contraindicated in pregnancy

Resistance: decreased uptake into cells or increased efflux out of cell by plasmid-encoded transport pumps

Front 12

Macrolides (3)

Mechanism
Clinical Use
Toxicity
Resistance

Back 12

Azithromycin, clarithromycin, erythromycin (-thromycins - don't confuse with other -mycins, esp streptomycin)

Mech: Bacteriostatic. Inhibit protein synthesis by blocking translocation ("macroslides"); bind to the 23S rRNA of 50S ribosomal subunit.

Use: Atypical pneumonias (Mycoplasma [HIV prophylaxis], Chlamydia, Legionella), STDs (Chlamydia), and gram-positive cocci (Streptococcal infections in patients allergic to penicillin)

Tox: MACRO: Motility issues, Arrhythmia caused by QT prolongation, acute Cholestatic hepatitis, Rash, eOsinophilia. Increases serum concentration of theophyllines (asthma) and oral anticoagulants.

Resistance: Methylation of 23S rRNA binding site

Front 13

Chloramphenicol

Mechanism
Clinical Use
Toxicity
Resistance

Back 13

Mech: blocks peptidyltransferase at 50S ribosomal subunit. Bacteriostatic

Use: Meningitis (H. influenzae, N. meningitidis, S. pneumoniae). Conservative use owing to toxicities but often still used in developing countries because of low cost.

Tox: anemia (dose-dependent), aplastic anemia (dose-independent), gray baby syndrome (in premature infants because they lack liver UDP glucuronyl transferase)

Resistance: plasmid-encoded acetyltransferase that inactivates drug

Front 14

Clindamycin

Mechanism
Clinical Use
Toxicity

Back 14

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Front 15

Sulfonamides

Mechanism
Clinical Use
Toxicity
Resistance

Back 15

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Front 16

Trimethoprim

Mechanism
Clinical Use
Toxicity

Back 16

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Front 17

Fluoroquinolones (8 + 1 quinolone)

Mechanism
Clinical Use
Toxicity
Resistance

Back 17

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Front 18

Metronidazole

Mechanism
Clinical Use
Toxicity

Back 18

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Front 19

Isoniazid

Mechanism
Clinical Use
Toxicity

Back 19

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Front 20

Rifampin

Mechanism
Clinical Use
Toxicity

Back 20

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Front 21

Pyrazinamide

Mechanism
Clinical Use
Toxicity

Back 21

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Front 22

Ethambutol

Mechanism
Clinical Use
Toxicity

Back 22

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