Efficacy and tolerability of once-daily cephalexin in canine superficial pyoderma: an open controlled study

OBJECTIVES

The aims of this study were to evaluate the efficacy and tolerability of oral cephalexin given at 30 mg/kg once daily in dogs with superficial pyoderma and to compare them with those of oral cephalexin given at 15 mg/kg twice daily.

METHODS

Twenty dogs with superficial pyoderma were treated with cephalexin at 30 to 60 mg/kg orally once daily (group A) and compared with 20 dogs treated at a dose of 15 to 30 mg/kg orally twice daily (group B). Dogs were treated until 14 days after clinical remission. Type and distribution of lesions, pruritus and general health status were assessed every 14 days using a numerical scale until 14 days after treatment discontinuation. Total scores for each evaluation day were compared between the two groups as well as time to obtain resolution and percentage of relapses.

RESULTS

Resolution of superficial pyoderma was obtained in all dogs in 14 to 42 days (median 28 days for both groups), with no difference between groups. Six dogs experienced vomiting or diarrhoea but did not require discontinuation of the treatment. Only one dog (in group A) relapsed nine days after treatment discontinuation.

CLINICAL SIGNIFICANCE

Once-daily cephalexin is as effective as twice-daily cephalexin in the treatment of canine superficial pyoderma.

Pharmacokinetics of two once-daily parenteral cephalexin formulations in dogs

The aims of this study were to describe and compare the pharmacokinetic profiles and T(>MIC90) of two commercially available once-daily recommended cephalexin formulations in healthy adult dogs administered by the intramuscular (i.m.) route. Six beagle dogs received a 10 mg/kg dose of an 18% parenteral suspension of cephalexin of laboratory A (formulation A) and laboratory B (formulation B) 3 weeks apart. Blood samples were collected in predetermined times after drug administration. The main pharmacokinetic parameters were (mean +/- SD): AUC((0-infinity)), 72.44 +/- 15.9 and 60.83 +/- 13.2 microg.h/mL; C(max), 10.11 +/- 1.5 and 8.50 +/- 1.9 microg/mL; terminal half-life, 3.56 +/- 1.5 and 2.57 +/- 0.72 h and MRT((0-infinity)), 5.86 +/- 1.5 and 5.36 +/- 1.2 h for formulations A and B, respectively. T(>MIC90) was 63.1 +/- 14.7 and 62.1 +/- 14.7% of the dosing interval for formulations A and B, respectively. Median (range) for t(max) was 2.0 (2.0-3.0) h and 3.0 (2.0-4.0) for formulations A and B, respectively. Geometric mean ratios of natural log-transformed AUC((0-infinity)) and C(max) and their 90% confidence intervals (CI) were 0.84 (0.72-0.98) and 0.83 (0.64-1.07), respectively. The plasma profiles of cephalexin following the administration of both formulations were similar. No statistical differences between pharmacokinetic parameters or T(>MIC90) were observed, however, bioequivalence between both formulations could not be demonstrated, as lower 90% CI failed to fell within the selected range of 80-125% for bioequivalence.