Penicillin Flashcards
General structure (3)
Penicillin
- Acyl side chain
- Beta-lactam ring
- Thiazolidine Ring
Beta-lactamase inhibitor
Penicillin
Clavulanic acid
sulbactam
Tazobactam
Drug for better porin penetration
- Gram negatives
(Penicillin)
Ampicillin
Mechanism of Action
Penicillin
inhibit cell wall synthesis
target Penicillin-binding proteins (PBPs)
PBPs
Penicillin
Transpeptidase, transglycolases, D-Ala carboxykinase
peptidoglycan transpeptidase
Resistance
Penicillin
B-lactamase production
Decreased penetration to site of action (G- / porin channel)
Most imp route of elimination
Penicillin
Renal excretion
Why do infants excrete PCN at a slower rate
immature transport systems
Equation used for renally excreted drugs
Cockroft-Gault Equation
[(140-age)(Weight)]/[(Serum Creatinine)(72)]
multiply by 0.85 for female. weight in Kg
How long does it take for PCN to yield peak levels
1-2 hrs after ingestion
What areas does PCN distribute to
Lung liver muscle kidney bone placenta
Lowest distributions are found in (2)
Lung and bone
Highest concentration found in
Urine
Most common hypersensitivity reaction
Penicillin
Maculopapular rash
Which Ig mediates immediate reaction - anaphylaxis ?
IgE
anaphylaxis –> to the ER
Which Igs mediate delayed reaction?
IgM or IgG
Adverse effects
Penicillin
Eosinophilia Interstitial nephritis (Methicillin) Pseudomembranous Colitis
Other causes of Eosinophilia
NAACP
Neoplasm Asthma Allergic reaction Connective tissue Parasite
What should you be be careful with Pen G?
hyperkalemia
Which Pen G is the best option? Why?
Benzanthine Penicilin (IM)
Sustained (slow) release
Prophylaxis in rheumatic fever
Causes/types of/for Pen G/VK resistance (3)
G+
Staph –> produce B-lactamases
Strep –> PBP changes (patients who’ve recieved abx recently)
Gonorrhea resitance
Penicillinase resitant penecillins
Antistaphylococcal penicillins
- IV - methicillin, oxacillin, nafcillin (hepatic elim)
- PO - cloxacillin, dicloxacillin
Amino group allows for penetration into which bacterium cell wall? (aminopenicillin)
G-
Two types of aminopenicillins
ampicillin
amoxicillin
adverse effects of aminopenicillin
hypersensitivity
Diarrhea
What is special about Carboxypenicllin?
increased permeability to cell wall
includes SPACE bugs
no Enterococcus coverage
Two types of Carboxypenicillin?
which is more active against Pseudomonas?
Carbenicillin
Ticarcillin - more active
Ticarcillin has a high ___ load. Patients with ____ could have issues with its excretion.
Na+
Congestive Heart failure
Adverse effects of Carboxypenicillin
hypersensitivity
Platelet dysfunction (dose dependent)
Na+ overload
Which penicillin is better than Ticarcillin? why?
Piperacillin (Ureidopenicillin)
lower Na+ load
also covers enterococcus
Why is B-Lactamase inhibitor and penicillin combos important/more useful?
Adds Staph and anaerobe coverage
Examples of Combo products:
Penicillin
Timentin - ticarcillin/clavulanic acid
Zosyn - piperacillin/tazobactam
