Macrolides Flashcards
Give 3 examples of macrolides
- Clarithromycin
- Erythromycin
- Azithromycin
Are all drugs that end in -mycin macrolides?
No, e.g. neomycin, tobramycin
What is the mechanism of action of macrolides?
Inhibit bacterial synthesis by reversibly binding to the 50s subunit on the ribosome, preventing elongation of the bacterial protein chain
Are macrolides broad or narrow spectrum?
Broad
What are macrolides effective in treating?
Gram +ve and some gram -ve bacteria
When might macrolides be used as an alternative to penicillin?
In penicillin allergic patients
What are the routes of delivery of macrolides?
PO
IV
What are the indications for macrolides?
- Respiratory tract infections
- Mild-moderate soft tissue infections
- As part of H pylori eradication therapy
- Chlamydia trichromatis
- Acne rosaecea
- Lyme disease
Give an example of a mild-moderate soft tissue infection that macrolides may be used to treat
Cellulitis
What macrolide is used as part of H. Pylori eradication therapy?
Clarithromycin
What macrolide is used to treat chlamydia?
Erythromycin
What are the cautions for macrolides?
- QT elongation
- Myasthenia gravis
Why should macrolides be used with caution in patients with QT elongation?
QT prolongation is a serious side effect of this drug
Why should macrolides be used with caution in patients with myasthenia gravis?
Condition can be exacerbated by macrolide use
How is azithromycin different from other macrolides in terms of interactions?
It does not inhibit cytochrome P450, and thus is involved in very few drug interactions
so the interactions here may or may not apply to azithro so just check BNF in the exam :)