Bacterial Cell Wall Synthesis Inhibitors Flashcards
What are the examples of Gram +ve cocci?
Staphylococcus
Streptococcus
Enterococcus
What are the examples of Gram +ve Bacilli?
Listeria monocytogenes Bacillus Clostridium species Diptheria Actinomyces Mycobacterium Corynebacterium
What are the examples of Gram -ve Cocci?
Neisseria gonorrhoeae (gonococci) Neisseria meningitides (meningococcus) Moraxella catarrhalis
What are the examples of Gram -ve Bacilli?
Pseudomonas aeruginosa
Enterobacteriaceae family (Includes Enterobacter species, Klebsiella pneumoniae, E.Coli, etc.)
Acinetobacter species
H. influenzae
What is the MOA of b-lactams?
Interfere with the synthesis of the bacterial cell wall peptidoglycan
Bind to active site of PBP (transpeptidase enzyme), which catalyses the cross-linking of the terminal peptide components of the linear polymer chains.
Weakens cell wall structure, build up in the intracellular osmotic pressure and lysis of bacterial cells; bactericidal to actively growing cells
Name the 3 Penicillin G
P G Potassium
P G Procaine
P G Benzathine
ROA for Penicillin G Potassium
IV
ROA for Penicillin G Procaine and Benzathine
IM
ROA for Penicillin G
Parenteral
ROA for Penicillin V
Oral, better abs than Pen G as it is more acid stable
Natural penicillins are useful against
b-lactamase negative strains of selected Gram +Ve (Streptococci, Bacillus diphtheriae) and Gram -ve (meningcocci and gonococci)
What are the main Gram +VE organisms that is targeted when using natural penicillins?
Streptococci, Bacillus diphtheriae
What are the main Gram -VE organisms that is targeted when using natural penicillins
Gram -ve (meningcocci and gonococci)
Which Penicillin is used to treat syphilis?
Pen G Benzathine
Which organism causes syphilis?
Spirochetes; Treponema pallidum
None of the penicillins are effective against _______
amoebae, plasmodia, rickettsiae, fungi, or viruses
How is the penetration into CSF for natural penicillin G?
IV aqueous Pen G reaches higher conc than procaine/benzathine. Penetration is increased if the meninges are inflamed.
Excretion of natural penicillins?
Renal, excreted unchanged in urine
Pen G procaine and benzathine can distribute into ____
storage tissues and released slowly (IM)
What are the names for Penicillinase-resistant penicillins?
Cloxacillin
Flucloxacillin
Methicillin (not in use)
ROA of Penicillinase-resistant penicillins?
IV, IM, Oral
Main organisms targeted in Penicillinase-resistant penicillins?
Staphylococci
Ineffective against Gram -ve
All are less effective against microorganisms susceptible to Pen G.
Penetration into CSF for Penicillinase-resistant penicillins?
Doesn’t achieve therapeutic levels
Excretion of Penicillinase-resistant penicillins?
Renal clearance
Penicillinase-resistant penicillins are best taken on an ______
empty stomach.
The bulky side groups of b-lactamases-resistant penicillin confers protection from b-lactamases by _____
limiting accessibility to the catalytic site of action
Penicillinase-resistant penicillins =
Anti-staphylococcal penicilin
Aminopenicillins =
Broad spectrum penicillins
Names of Aminopenicillins
Ampicillin
Amoxicillin
ROA of ampicillin
Acid stable; Oral, IV
ROA of amoxicillin
Oral (better abs than ampicillin), IV
Aminopenicillins have additional ____ groups, allowing ______ via _______
Aminopenicillins have additional hydrophilic groups, allowing their penetration into Gram -ve bacteria via porins
Aminopenicillins are used for many ______
b-lactamases negative strains of many Gram -ve/+ve MO
Aminopenicillins doesn’t cover
Pseudomonas or Klebsiella
Penetration into CSF for Aminopenicillins
Parenteral ampicillin and amoxicillin can reach adequate CNS concentrations
Penetration is increased with inflamed meninges
Excretion of Aminopenicillins
Renal; Excreted unchanged in the urine.
Dose adjustment required for renal dysfunction.
Incomplete oral abs of ampicillin results in higher incidence of ___
diarrhoea
Antipseudomonal penicillins =
Extended spectrum penicillins