Effect of Garcinia kola, Heckel on bioavailability of two commonly used drugs (Sulphamethazine and Paracetamol)

Abstract

The effects of concurrent administration of Garcinia kola Heckel (Guttiferae) seed suspension were investigated on the bioavailability of two commonly used drugs: sulphomethazine and paracetamol in albino rabbits. Two groups of rabbits (n=4) were treated by gavage with a concentration of 0.5g/kg body weight of seed suspension given concurrently with 150mg/kg body weight of sulphonamide and paracetamol respectively. Control groups were given equivalent doses of either drug alone. Blood was withdrawn from the left ear at one hour intervals for five hours. Results showed that G. kola seeds decreased significantly (p < 0.05) the bioavailability of the two drugs. Relative bioavailability was calculated to be 77.56% for sulphonamide and 75.39% for paracetamol. The time of peak and the peak concentration were also reduced while the concentration at one hour was only significantly different for paracetamol at p < 0.05. These results suggest that G. kola seeds may reduce bioavailability by interfering with drug absorption across the gastrointestinal mucosa.