Block 4 Pharm
Card Set Information
Block 4 Pharm
Pharm 1 flash cards
What are the Natural Penicillins?
Penicillin G and Phenoxymethyl Penicillin (penicillin V)
What are the longer half life Penicillin G
Procaine penicillin - 6 to 8 hour half life
Benzathine penicillin 6 day half life
What are the penicillinase resistant(anti staphylococcal) penicillins
Methicillin- no longer used
Oxacillin parenternally administered
Nafcillin parenternally administered
Cloxacillin Given orally 50% oral availability
Dicloxacillin " " "
What are the extended range penicillins (used more often for gram negative bacteria) all 1 hour half life
: Given P or O
: given orally 75% oral availability
What does Probenecid do?
Blocks urinary excretion of penicillins.
What 2 penicillins are excreted into the biliary tract?
Ampicillin only partly and Nafcillin mostly
What is the mechanism of action of Penicillins?
Work best on actively proliferating organisms, they interefere with cell wall synth by:
Binding receptors on the bacterial cytoplasmic membrane
Inhibiting transpeptidases that are responsible for cross linking peptidoglycans
or activation of autolytic enzymes
Mechanisms of microbial resistance to beta lactam antibiotice (penicillins)
Formation of Beta Lactamases that destroy the drug
Mutation of penicillin binding targets
Alteration of porins to decrease penetration of the drug.
What are the narrow spectrum penicillins?
G and V- used to treat :
Strep Pyo (group A)
Strep pneumo (if sensitive strain)
some gram positive anaerobes
Which penicilins are beta lactamase resistant?
Nafcillin, Oxacillin, Cloxacillin, and Dicloxacillin
used to treat sensitive strains of staph aureus and Staph epidermitis
What are the 2 extended range penicillins?
Ampicillin and Amoxicillin- used to treat:
E. coli, Proteus mirabilis, Salmonella, Shigella, H influenzae, H. pylori
Listeria monocytogenes- all strains sensitive
What 2 drugs are used to treat pseudomonas and some gram negatives?
Ticarcillin and Piperacillin