Macrolides Flashcards
What is the general structure of macrolides?
Lactone ring + deoxy sugars
What are the main targets and macrolides and how do they act?
G+ and some G-, MSSA
Mostly static
What are the mechanisms of action of macrolides?
Inhibit translocation from A to P site
Release peptide tRNA from ribosomes
Block formation of initiation complex
What was the first Rx against Legionnaires Disease?
Erythromycin
What does erythromycin inhibit?
CYP3A4 which causes prolonged repolarization by effecting the K= channel (Torsades de Pointes)
What are some cross Rx interactions of erythromycin?
5X increased risk of sudden death if taking diltiazem or verapamil
How does erythromycin act prokinetically?
Motilin receptor agonist used for post-op to stimulate peristalsis and speed up gastric emptying w/ gastroparesis
Where does azithromycin concentrate?
Intracellularly
In what cases do you use azithromycin?
Community acquired pneumonia, Legionnaires, mycobacterium avium complex (MAC)
What is the t1/2 of Azithromycin?
70 hrs
Does azithromycin inhibit P450?
Nope
What is the FDA warning about azithromycin?
Can cause changes in electrochemical activity of the heart with can cause potentially fatal arrhythmias
What do you use clarithromycin for?
Community acquired pneumonia, MAC
How is clarithromycin immunomodulatory?
Inhibits mRNA transcription for proinflammatory cytokines (IL-8, NF-kB, AP-1)
What should you take caution with when taking clarithromycin?
Can lower blood sugar
Also w/ colchicine > possibly fatal
