Clarithromycin pharmacokinetics after oral administration with or without fasting in crossbred beagles

Clarithromycin was administered to eight dogs intravenously and orally. A suspension or a tablet was given to animals both immediately after feeding and on an empty stomach. Neither the formulation nor the time of administration in relation to feeding significantly influenced the pharmacokinetic parameters. The lowest mean (+/-SD) maximum plasma concentration (Cmax) of 3.0 +/- 0.6 micrograms/ml, the lowest bioavailability (F) of approximately 69 per cent and the shortest time above the proposed breakpoint of susceptibility (L) of 2.9 +/- 1.3 hours were observed with the suspension after feeding. The highest Cmax of 3.6 +/- 0.8 micrograms/ml, the highest F of 83 per cent and the longest L of 4.5 +/- 2.0 hours were observed with the suspension in the fasted group. The mean time at which Cmax occurred (tmax) was between one and two hours after administration. In conclusion, clarithromycin is potentially suitable for therapeutic use in dogs, pending species-specific studies of safety and therapeutic efficacy.