Drugs for Bacterial Pulm Infections Flashcards
What is the MOA of tetracycline class drugs?
inhibition of protein synthesis by REVERSILBE binding of 30S ribosome. Bacteriostatic
What do the side groups of penicillins do?
provide different chemical, pharmacological and antimicrobial properties
What is clavulanate?
a B-lactamase inhibitor often given with penicillin or other B lactams to overcome resistance
What are the natural penicillins and what are they effective against?
penicillin G (parenteral) and penicillin V (oral).
effective against gram+ cocci (S. pneumo).
Ineffective against most gram- and staph aureus strains
What are the aminopenicillins and what are they effective against?
ampicillin and amoxicilin
effective against gram+ AND gram- (like heamophilus Influenza and E. Coli)
What is agumentin? What is it effective against?
Augmentin is amoxicillin (an aminopenicillin) combined with clavulanic acid (a B-lactamase inhibitor).
The clavulanic acid extends the spectrum of penicillin to include MSSA (staph aureus) and anaerobes
Are Pen V drugs resistant to acid? Should they be taken with or without food?
Penicillin V drugs are resistant to acid destruction, but they should be given 1 to 2 hours AFTER meals to avoid high acid levels and improve absorption.
How are penicillins metabolized and excreted?
hepatic enzyme metabolism and 90% renal tubular excretion.
What is the most common adverse effect of penicillins?
Allergic reactions. Potentially serious.
AAD (antibiotic associated diarrhea) also common though it is more prevalent in broad spectrum antibiotics.
Can cause hypokalemia becuase K+ is lost in urine during drug excretion.
What will modifications at position 7(R1) of the B-lactam ring in cephalosporins do? Modifications of the 3(R2) position of the dihydrothiazine ring?
7(R1) alters the antibacterial activity.
3(R2) alters the metabolism and pharmacokinetic properties
Describe the differences between 1st and 3rd generation cephalosporins?
1st –> 3rd gen have 4 differences:
- More Gram- action
- Less Gram+ action
- increased B-lactamase resistance
- Increased CSF permeability
What are the 3rd gen cephalosporins? What bugs are they effective against?
cefotaxime, ceftriaxone, ceftazadime, and cefixime.
Effective against H. influenza and pseudomonas(ceftazadime only)
Are cephalosporins effective against enterococci?
NO. not at all
What allows imipenem and other carbapenems to be effective against gram-?
small hydroxyethyl side chain grants high effectiveness against most Gram- bacteria. They are the broadest spectrum of any B-lactam antibiotic
What must imipenem be administered with? Why?
MUST be given with cilastatin to inhibit dehydropeptidase to prevent drug breakdown and renal toxicity