Mandell ch. 29:
Macrolides do not have all that great oral bioavailability

Much higher tissue penetration than serum levels

Azithromycin tissue half-life is 2-4 days, so likely retains significant antibacterial activity for 5 days after a 5 day course
1/16

#IDTwitter #idmeded Macrolides, clindamycin and chloramphenicol all bind at the same site of the 50S ribosome, preventing early chain elongation. They may competitively inhibit each other if used together
2/16

Mandell ch. 26:
Doxycycline acts on 70S ribosomes in mitochondria (in addition to 30S bacterial ribosomes), which gives it activity against protozoa and Plasmodium
1/13
#idtwitter #idmeded We all know doxy (and tetra's in general) have awesome spectra of activity, but here's some factoids:

🔹They can be used for all Vibro spp.

🔹Listeria is only intermediately susceptible to doxy with larger inocula

🔹Minocycline has better activity against Acinetobacter
2/13

Mandell ch. 25:
There are so many more aminoglycosides than I ever thought 😅

AGs are characterized by concentration-dependent killing (high peak/MIC is desirable), the post-antibiotic effect, and synergism
1/12
#IDtwitter #idmeded The higher the external (to the 🦠) concentration of AG, the more AG gets inside the 🦠 and the quicker it induces death...hence higher peak/MIC and AUC/MIC

Many many trials have shown once-daily dosing is = or superior to BID/TID in many different diseases/populations
2/12