…and has been covered extensively elsewhere 4. Worrying about the C.diff rates with Clinda and then recommending a Cephamycin as an alternative is nonsensical 5. See picture. The defence rests 2/2

And here it is, Listeners Dearest The ID:IOTS Antibiotics Tier List Want to argue? Curse our names to God? Go right ahead; but sub to Pod And tell your friends about us, although It's likely it'll annoy them also podcasts.apple.com/gb/podcast/i...

The ‘medium’ & ‘narrow’ columns I’ve got more of an issue with; I’d probably move Vanc & Clinda into ‘medium’; here I think I’m being partially influenced by the UK version of WHO’s AWaRe classification of ABx:

KASIC Putting or another brilliant post on De-escalation of ABx with some brilliant references about how de-escalation is associated with BETTER OUTCOMES for patients! Let’s talk about this table though, as it’s been on my mind. 🪡

I AM SUCH A SILLY SAUSAGE I FORGOT ALL THE NONBACTERIAL SPECTRA! Here you are

Ah yes, the famously medium-spectrum doxycycline. It only covers Staphylococci Pneumococci Beta haemolytic Streptococci Actinomyces Mycoplasma Chlamydophila Legionella H.influenzae Moraxella catarrhalis ESBL E.coli UTI Pseudomonas UTI(maybe!) Burkholderia pseudomallei Vibrio H.pylori 1/2

600mg TID apparently

Let’s look at EUCAST dosing guidance: this gives us an added dosing difference: High dose PO Co-Amox is 875/125 - a 9:1 ratio! Incidentally if you’re in the UK and you’ve seen ID recommend Co-amox 625 + Amox 500mg, both 8-hourly, this is why; we’re trying to approximate the EUCAST high dosage.

Good question! #idsky #microsky 🪡 Co-amoxiclav is generally dosed in the UK as follows: PO: 500mg Amox / 125mg Clavulanate IV: 1000mg Amox / 200mg Clavulanate Both 8-hourly. This gives you differing ratios of Amox to Clav (4:1 for PO, 5:1 for IV). What gives?

In the UK: mostly. That pic is from our ESPAUR report on AMR. I’d use it empirically to cover S.pneumo & MSSA, ie post-viral bacterial infection as we’re discussing here. MRSA? Is want an antibiogram demonstrating the isolate was Doxy S.

1G-Cephs only thing as good as ASP for serious MSSA infection, I don’t see why that wouldn’t be the case here. More worrying (maybe) would be a lack of S.pneumo breakpoints for 1G-cephs (see pic; green = has a EUCAST breakpoint); but I figure if it covers BHS/AHS it probs covers pneumococcus too

Doxycycline. I actually have an (unpublished) episode on this, borne out of a hate of local prescribing practice. Local (UK) data is in this doc: assets.publishing.service.gov.uk/media/5a7cd0... Mostly it’s S.pneumo, MSSA, GAS, H.influenzae. Doxy/clari should handle all that (here at least)

NEW EPISODE! This week Callum takes the boldest step yet in improving the podcast: getting rid of Jame! Join Callum & Alyssa this week as they Migrate the Marvellous Mountains of Minutiae on Moulds, (di)Morphs, Many yeasts and Mycology in general! #IDsky podcasts.apple.com/gb/podcast/i...

Might I venture that someone needing to go on Cefazolin&Rifampicin might also be at risk of coagulopathy? This is the only interaction between these agents in the BNF (which I’d also never heard of)

I think it’d work, @bjegorovic.bsky.social , but I’d probably go with an approved Endocarditis regimen from ESC23 that has good CNS penetrate until the full extent of infection was clarified. Cefaz 6g/d is listed as an option for NVE there, and it can replace ASP too in PVE (alongside Rif/Gent 🙄)

250k downloads? 100 episodes? Podcast going for >3yrs 6months 3 weeks? Putting up with Callum’s crap for the same amount of time? Collabs with @febrilepodcast.bsky.social, @letstalkmicro.bsky.social, MicrobeMail & @sidpharm.bsky.social #breakpoints? COMPLETED IT MATE #idsky #humblebrag

ONE ANTIBIOTIC PK TABLE TO RULE THEM ALL Absorption takes drug into blood from GI, Vd spreads drug out to where bug calls home. And after bacteria are doomed to die, The drug’s eliminated on the porcelain throne In the Land of Notion where this table doth lie… #idSky #microsky #pharmsky #medsky

Ask and we shall answer! METRONIDAZOLE DOSING IS A NIGHTMARE AND MAKES NO SENSE Thread🪡 #IDSky

Well, it’s official folks. We’re on BlueSky full time. You want to interact with us? Do it here, don’t message on X/twitter. Don’t want to interact with us? Perfectly understandable, continue to ignore us, probably the best thing for all concerned.

Our local guidance attached, though it’s based on UKHSA guidelines. As an inpatient physician it doesn’t really come up much, but I’d follow this guidance if it did. Not that I’m a big fan of Oseltamivir in general.

System is developed enough to handle Ceftriaxone’s biliary excretion. Sanjay Patel et al in Paediatric AMS land have been developing AMS guidance (here: uk-pas.co.uk/Antimicrobia...), and have this to say on the Ceftriaxone issue:

Mostly SABATO agents but a) the UK doesn’t have a terrible S.aureus resistance problem, and b) due to C.diff based aversion to Clinda, I don’t use it a lot.

Or... if you don't have time just read this excellent Infection Quick Reference Guide: www.britishinfection.org/application/... (OR even better listen AND read this...) There are more helpful IQRGs here: www.britishinfection.org/guidance/pub...

So not very encouraging, is it? BUT: NICE pyelonephritis guidance (www.nice.org.uk/guidance/ng1...) says you can use it in doses of 3-6g/d 4 severe infections: So it’s useless for BSI but JUST FINE 4 pyelo? Renal Parenchymal antibiotic levels approximate plasma levels; this doesn’t make sense

Here the solid line is Cefalexin 1g QID (dotted line is Cefalexin + probenecid 500); so if you’re aiming to get over a MIC of 16 in plasma (ie for BSI), you’re getting Stasis (T>MIC 30%) but not 1-log kill if you’re using Cefalexin on its own; adding probenecid gets you ~50% chance of 3-log kill?

Cefalexin has EUCAST breakpoints 4 enterobacterales, but only ‘uncomplicated UTIs’; the S/R breakpoint is 16 (NB: For Staph & Strep Cefalexin susceptibility is inferred from cefoxitin & benpen sensitivity, respectively [CLSI Enterobacterales BPs are inferred from cefazolin {urine infections only}])

I have many thoughts! Let’s talk about Cefalexin use in bacteraemia! A new year’s thread…

225k total downloads 3years (4months) 2 hosts And 1 more year of podcasting under our belt! Here’s to another, @CallumPMutch. Of all the things I pay to do (keep pets, raise children, browse Netflix but never actually watch anything), THIS is my fave! #IDsky #infection #podcast

Our local protocol for ambulating patients with SSTI. didn’t even occur to me to “double-cover”! We’re in a low-prevalence area for MRSA though, so might not work everywhere. Decent success rates with Cefalexin TID, less frequent admin than SoC (Fluclox QID), and CoTrim for more tricky cases!