Antimicrobial dosing editorial in Lancet

[Praziquantel86]

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An editorial just showed up in the Lancet advocating for the use of weight-based dosing for many antimicrobial agents. I generally agree with their thoughts, but practically, I just don't think it's possible. Many of the most commonly used antibiotics are generic, and no drug company would ever fund the additional studies necessary. Likewise, I doubt the NIH would try to pick up the slack, either.

I think a more reasonable option might be a move to serum concentration monitoring. There are some data regarding optimal serum values for a large range of antibiotics, so it wouldn't be too much of a stretch to use those numbers on a larger scale.

Here's the citation if anyone is interested, I don't really feel like talking to myself...

Falagas ME, Karageorgopoulus DE. Adjustment of dosing of antimicrobial agents for bodyweight in adults. The Lancet; Jan 16 2010. (375) 9710:248-51

 

[patmcd]

Serum level monitoring is only really practical for inpatients, not to mention I'd bet serum level tests don't come cheap (at least until they are widely used).

 

[njac]

Even the common ones are $$ at my hospital a vanco level is $100 and an AG is $120

 

[Praziquantel86]

Yeah, come to think of it, that's not such a good idea for routine use (not to mention the fact that I completely forgot about outpatient use...).

I think my main issue is that it is, at this point, not possible for most people. The data exists for fixed dosing, but there is no real way to tell what the proper weight-based dose would be. Would you lower a dose for an underweight patient, or would you stick to only increasing the dose for overweight patients? Who at this point would be willing to undertake a clinical trial? What would be the cost, and time, required to individualize every dose of every antibiotic?

I guess this is the issue that the pediatric folks have been having for years...I'm not sure if they've found the answers either.

 

[Omegadramon]

I can see making a case for it in obese patients, but even then...its all about serum concentrations.

We had a 600lb pt this past weekend who needed Amikacin. Everybody was like (😵), who wants to verify 1500mg of Amikacin. I don't know what happened to the patient.

 

[Priapism321]

We had a 600lb pt this past weekend who needed Amikacin. Everybody was like (😵), who wants to verify 1500mg of Amikacin. I don't know what happened to the patient.

5 mg/kg of amikacin worried you guys? That is actually fairly low dose. I weigh 75 kg, and if I showed up with a granulocyte count of zero, hypotension, and a fever, I hope someone would dial me up a dose of somewhere in the neighborhood of 1,500 mg.