Uniprim one or twice daily?

[Ghazzu]

I’ve always used it at 12 hour intervals. 30 mg/kg
I was taught that, and it is listed that way in multiple formularies.

From Plumb’s:

The veterinary product, trimethoprim/sulfadiazine is labeled for once daily administration in dogs and horses, but many clinicians believe that the drug is more efficacious if given twice daily, regardless of which sulfa is used.

[JB]

Thanks Ghazzu! Do you know of any studies on that? “believe” is usually not reserved for clinicians LOL

[Mistral]

Thanks everyone for weighing in, and to those that provided some links to studies. This is interesting!

[Ghazzu]

@JB

Thanks Ghazzu! Do you know of any studies on that? “believe” is usually not reserved for clinicians LOL

Now that I’m home from the herb symposium, I’ll try to find some pharmacokinetic references.

[Ghazzu]

There’s this: http://avmajournals.avma.org/doi/abs/10.2460/ajvr.2002.63.349

Ratios of trimethoprim and sulfamethoxazole optimum for antibacterial activity are maintained for only a short duration in horses, donkeys, and mules.

http://www.sciencedirect.com/science/article/pii/003452889390054J

A point for once-daily oral dosing, though a small number of horses in the study:

It is concluded that SMM-TMP administered orally once a day at 20 mg and 4 mg kg[SUP]−1[/SUP] bodyweight, respectively, maintains therapeutic concentrations, whereas twice daily intramuscular administration would be more effective for treating systemic infections in the horse than the once a day regimen usually adopted in veterinary practice.​​​​​​​

Haggett, E. F. and Wilson, W. D. (2008), Overview of the use of antimicrobials for the treatment of bacterial infections in horses. Equine Veterinary Education, 20: 433–448.

The ratio of TMP to sulphonamides is
important and was originally matched at a 1:5 ratio for
administration to man. In horses, the more rapid elimination
of TMP relative to sulphonamides leads to suboptimal drug
ratios at the site of action (van Duijkeren et al. 1994) and
makes twice daily administration necessary.

This last citation is along the lines of what I was taught was the issue.

[JB]

Ahhh, I see. Thank you!