Aminoglycosides

Question 1

mechanism of action

Answer 1

• work similar to TETRACYCLINES; binding to the 30S RIBOSOME & preventing protein synthesis

Question 2

Do aminoglycosides work with any other medications?

Answer 2

• works closely with BETA-LACTAMS or VANCOMYCIN - helps to create a SYNERGISTIC EFFECT
• most often the BETA-LACTAM is given first in order to BREAK THE BACTERIAL CELL WALLS
• once broken, the AMINOGLYCOSIDE can enter to inhibit protein synthesis

Question 3

postantibiotic effect

Answer 3

• period of CONTINUED BACTERIAL GROWTH SUPPRESSION that occurs AFTER short-term antibiotic exposure
  
  • **also seen in CARBAPENEMS

Question 4

indications

Answer 4

• treats SERIOUS GRAM-NEG and GRAM-POSITIVE INFECTIONS

gram-neg;
- proteus
- escherichia coli
- psuedomonas
- sepsis

gram-positive;
- enterococcus
S. auerus
- bacterial endocarditis

• cystic fibrosis

Question 5

contraindications

Answer 5

• drug allergies
• pregnant women

Question 6

adverse effects

Answer 6

**IMPORTANT - these medications are very POTENT

• can cause NEPHROTOXICITY & OTOTOXICITY

Question 7

why do we need to utilize THERAPEUTIC DRUG MONITORING while taking aminoglycosides?

Answer 7

• want to monitor the RISK OF NEPHROTOXICITY and OTOTOXICITY by monitoring SERUM LEVELS
• want to monitor RENAL FUNCTION & SERUM CREATININE
• aminoglycosides only work by using CONCENTRATION-DEPENDENT KILLING

Question 8

CONCENTRATION-DEPENDENT KILLING

Answer 8

where the drug concentration must be a CERTAIN LEVEL ABOVE THE MIC to be the most effective in killing the bacteria

**in order for aminoglycosides to work they must be at LEAST 8 TIMES HIGHER than the MIC (minimum inhibitory concentration)

due to such a need of a stronger concentration, there is a risk of NEPHROTOXICITY or OTOTOXICITY

Question 9

once-daily dosing

Answer 9

the most common method of DOSING for aminoglycosides due to their efficacy of concentration-dependent killing
- measuring TROUGH-LEVELS for maintenance; have to be lower than 2 mcg/mL

Question 10

TIME-DEPENDENT KILLING

Answer 10

this is the more common way antibiotics work;
the amount of TIME the drug is ABOVE the MIC the better the effectiveness in killing bacteria

Question 11

interactions

Answer 11

• INCREASED RISK WITH USE OF;
  
  • VANCOMYCIN
  • CYCLOSPORINE
  • AMPHOTERICIN B
  [increases the risk for nephrotoxicity]
  • LOOP DIURETICS
  [increases the risk for ototoxicity]

Question 12

amikacin

Answer 12

• used to treat infections RESISTANT to GENTAMYCIN or TOBRAMYCIN
• parenteral form

Question 13

gentamycin

Answer 13

• IV or IM, topical, drops, ointments
• treatment of infection for susceptible GRAM POSITIVE and GRAM NEGATIVE BACTERIA

Question 14

tobramycin

Answer 14

• similar routes to gentamycin
• used to treat PULMONARY INFECTIONS - cystic fibrosis

Question 15

neomycin

Answer 15

• treatment for BACTERIAL DECONTAMINATION OF THE GI before surgery
• can be given ORALLY or RECTALLY, topical
• treatment for E. coli bacteria, eye infections, hepatic encephalopathy