Aminoglycosides and Antimicrobial Agents

Question 1

Aminoglycosides

Answer 1

Gentamicin, Tobramycin, Amikacin, Streptomycin, Neomycin

Question 2

Aminoglycoside MOA

Answer 2

inhibit protein synt., intracellular, BIND IRREVERSIBLE TO 30S SUBUNIT (resistance opposite)

Question 3

Aminoglycoside Kinetics

Answer 3

cidal, conc. dependent killing, antimicrobial effect continues after conc. not measurable for 1-3 hours.

Question 4

Aminoglycosides

Answer 4

poor oral absorption, distribution to ECF, polar (enters cells through pores), poor CSF penetration, 99% unchanged by kidneys

Question 5

Aminoglycoside Monitoring

Answer 5

peaks and troughs daily 6-14 hours post dose, hartford nomogram

Question 6

Aminoglycoside ADR

Answer 6

ototoxicity, tinnitus, hearing loss, loss of balance, nephrotoxicity, respiratory paralysis

Question 7

Mycobacteria

Answer 7

intracellular pathogens, slow growing, can be dormant, cell wall impermeable to many agents, combo therapy required

Question 8

Tuberculosis

Answer 8

caused by mycobacterium tuberculosis, causes latent or active infection, 1/3 of world pop. infected

Question 9

Latent TB

Answer 9

treatment allows for lesser chance to contract active infection, isoniazid for 9mo., rifampin x4mo.

Question 10

Active TB

Answer 10

Rifampin, Isoniazid, pyrazinamide, ethambutol, lasts 6mo. but resistant strains could take up to two years to treat

Question 11

1st line Antimycobacterials

Answer 11

Isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin

Question 12

2nd line Antimycobacterials

Answer 12

Ethionamide, cycloserine, amkacin, aminosallicylic acid, capreomycin, clofazimine, levofloxacin, ciprofloxacin, rifabutin, rifapentine

Question 13

Isoniazid MOA

Answer 13

inhibits synt. of mycolic acids in cell wall, pro-drug, cidal, static in resting organisms. well absorbed, into CSF, metabolized in liver, out in urine, NO DOSAGE ADJUSTMENT IN RENAL IMPAIRMENT

Question 14

Isoniazid ADE

Answer 14

neuropathy (give with B6 supplementation), hepatits, GI, CNS, Rash

Question 15

Rifampin MOA

Answer 15

RNA polymerase inhibitor, cidal, staph, H. influenzae, neisseria, p450 inducer, excreted into bile

Question 16

Rifampin ADE

Answer 16

ORANGE/RED URINE TEARS SWEAT, jaundice, hepatotoxic

Question 17

Pyrazinamide MOA

Answer 17

woks in the lysosomes and macrophages, cidal, CSF penetration, liver metab. renal excretion (do dose adjust), ADE: hyperuricemia, hepatotoxic

Question 18

Ethambutol

Answer 18

Inhibits arabinosyl transferase which is involved in synthesis of cell wall, static, CSF pen. w/ inflammation, renal excretion (dose adj)

Question 19

Ethambutol ADE

Answer 19

RETROBULBAR NEURITIS (optic neuritis), red/green color blindness, reversible when stopped

Question 20

2nd line agents

Answer 20

b/c increased risk of toxicities, not more effective than first line, active against atypical strains of TB,