RELATIVE BIOAVAILABILITY OF ATOVAQUONE SUSPENSION WHEN ADMINISTERED WITH AN ENTERAL NUTRITION SUPPLEMENT

OBJECTIVE: To compare the relative bioavailability of a single atovaqu one 750 mg suspension oral dose when administered in the fasting state , after a normal breakfast, and after an enteral nutrition supplement DESIGN: Ten healthy volunteers received a single dose of atovaquone su spension 750 mg/5 mL while fasting. At 2-week intervals, the subjects were then randomized in a crossover design to receive the atovaquone d ose within 1 hour of consuming a normal breakfast (fat content 21 g) a nd 16 oz. of Sustacal Plus (fat content 28 g). Blood samples were coll ected at seven time points after each atovaquone dose. HPLC was used t o determine the atovaquone concentrations in plasma. RESULTS: Administ ering atovaquone suspension with either a normal breakfast or an enter al nutrition supplement, such as Sustacal Plus, significantly increase d the oral relative bioavailability. The mean AUC(0-24) after the fast ing dose was 43.4 mu g.h/mL. The mean AUC(0-24) values with breakfast (103.8 mu g.h/mL) and Sustacal Plus (118.8 mu g.h/mL) were significant ly greater compared with fasting (p < 0.0001). CONCLUSIONS: This study has shown that the new atovaquone oral suspension also has significan tly greater bioavailability when administered after food or a nutritio n supplement that has a moderate fat content. Patients who require ato vaquone therapy can use Sustacal Plus without risk of reduced absorpti on.