Oral fluconazole has variable pharmacokinetics in dogs

Area of Science:

• Veterinary Pharmacology
• Drug Bioavailability Studies

Background:

• Understanding drug pharmacokinetics is crucial for effective veterinary treatment.
• Fluconazole is a widely used antifungal medication.
• Variability in oral drug bioavailability can impact therapeutic outcomes.

Purpose of the Study:

• To evaluate the impact of food and different manufacturers on fluconazole's oral bioavailability in dogs.
• To investigate potential variability in fluconazole pharmacokinetics among different brands.

Main Methods:

• A randomized crossover study involving six healthy dogs.
• Administration of 100 mg fluconazole tablets from three manufacturers under fasted and fed conditions.
• Plasma fluconazole concentrations measured via mass spectrometry over 72 hours.

Main Results:

• Significant inter-dog variability observed in drug exposure (AUC/dose) and terminal half-life.
• Fed relative oral bioavailability ranged from 82%-90% compared to fasted state.
• Formulations were not bioequivalent due to substantial pharmacokinetic variability.

Conclusions:

• Drug half-life variability is a major factor in canine fluconazole pharmacokinetics.
• Feeding status and manufacturer had minor influences on bioavailability.
• Significant variability necessitates careful consideration of fluconazole formulations in dogs.