Mechanisms of Antibiotics

Question 1

need to know about patient

Answer 1

• history
• age-pH of gastric acidity is higher in chilren
• pregnancy
• renal and hepatic function
• site of infection

Question 2

pharmacokinetics

Answer 2

• all the ways the body manipulates the drug-absorption, distribution, metabolism, excretion
• longer half life can mean more time b/n doses or better CNS penetration

Question 3

pharmacodynamics

Answer 3

-biochemical and physiological effects of the drug and its mechanism of action on bacteria

Question 4

characteristics of an ideal antibiotic

Answer 4

• selective target
• bactericidal
• narrow spectrum
• high therapeutic index
• emergence of resistance is slow
• few adverse reactions
• various routes of administration
• good absorption
• good distribution to site of infection

Question 5

antibiotic mechanisms of action

Answer 5

• interference will cell wall synthesis
• interference with protein synthesis
• interference with PM membrane function
• interference with nucleic acid pathways
• interference with metabolic pathway

Question 6

current challenges with antibiotics

Answer 6

• extended spectrum B lactamases
• inducible amp c beta lactamases
• carbapenase producing gram negatives
• HA and CA MRSA
• inducible clindamycin resistance in Staph and strep
• staph with vancomycin resistance or reduced susceptbility
• VRE
• multi drug resistant pneumococcus (including vancomycin)

Question 7

MIC

Answer 7

• minimal inhibitory concentration-amt needed to stop growth- not necessarily killing
• want 4x this level-this needs to be low

Question 8

MBC

Answer 8

-minimal bacteriocidal concentration-lowest [ ] to kill organism

Question 9

where do antibiotics come from?

Answer 9

• environment
• only 8 new since 1998
• natural/semisynthetic/synthetic

Question 10

lipoglycopeptides

Answer 10

• telavancin
• gram pos skin and soft tissue infections
• structurally related to vanco

Question 11

cyclic lipopeptides

Answer 11

• daptomycin
• gram pos including MRSA
• binds to the bacterial membrane and causes rapid depolarization of the PM-inhibition of DNA RNA and protein synthesis

Question 12

glycylcyclines

Answer 12

• tigecycline
• gram pos and neg (MRSA)
• similar mech as tetracycline

Question 13

oxazolidinones

Answer 13

• linezolid
• MRSA and VRE
• inhibits protein synthesis by harming 50s