Antimicrobials

Question 1

Define empiric therapy

Answer 1

Therapy in which you don’t know exactly what the patient is suffering from, so you essentially do your best guess to prescribe a treatment plan for them

Question 2

Define prophylaxis

Answer 2

A preventative measure taken for a patient at risk of infection

Question 3

For beta-lactams, identify mode of action and if bacteriostatic or bactericidal.

Answer 3

Target: cell wall
Mode of action: Inhibit transpeptidase (PBP)
Bactericidal

Question 4

For glycopeptide drugs, identify mode of action and if bacteriostatic or bactericidal.

Answer 4

Target: cell wall.
Mode of action: inhibit assembly of PG.
Bactericidal.

Question 5

For aminoglycosides, identify mode of action and if bacteriostatic or bactericidal.

Answer 5

Target: protein synthesis.
Mode of action: binds to multiple ribosomes and prevents tRNA from forming initiation complexes. Bacteriostatic.

Question 6

For tetracyclines, identify mode of action and if bacteriostatic or bactericidal.

Answer 6

Target: protein synthesis.
Mode of action: binds to multiple ribosomes and prevents tRNA from forming initiation complexes. Bacteriostatic.

Question 7

For macrolides, identify mode of action and if bacteriostatic or bactericidal.

Answer 7

Target: protein synthesis.
Mode of action: binds to 50S subunit and blocks the translocation reaction. Bacteriostatic.

Question 8

For fluoroquinolones. identify mode of action and if bacteriostatic or bactericidal.

Answer 8

Target: DNA.
Mode of action: inhibit DNA topoisomerase.
Bactericidal.

Question 9

For sulfonamides, identify mode of action and if bacteriostatic or bactericidal.

Answer 9

Target: folate biosynthesis.
Mode of action: block folate precursors (folic acid is needed for RNA/DNA and protein synthesis). Bacteriostatic/bacteriocidal.

Question 10

For lipopeptides, identify mode of action and if bacteriostatic or bactericidal.

Answer 10

Target: Cytoplasmic membrane.
Mode of action: lysis.
Effective against Gram + only
Bactericidal.

Question 11

Identify the 3 drug subclasses that are considered beta-lactam drugs

Answer 11

Penicillins
Cephalosporins
Carbapenems

Question 12

Compare and contrast the mechanisms of action of antibacterial, antiviral, antifungal, and antiparasitic drugs.

Answer 12

Antiviral drugs treat infections but don’t typically cure them (target steps in the viral replication pathway). Most antifungal drugs target cell walls, plasma membranes, nucleic acid synthesis, chitin biosynthesis, microtubules, and ergosterol synthesis. Antiparasitic agents (antiprotozoan and antihelminthic drugs) are difficult to develop because the pathogen and the host are both eukaryotes, and the parasites have complex life cycles. Antibacterial drugs can be bacteriostatic or bactericidal, and can target the cell wall, DNA synthesis, membranes, ribosomes, or metabolic pathways.