The second part of the study will take place if no appreciable change in the pharmacokinetics of either F901318 or fluconazole has been observed in either the first or the second cohorts in the first part of the study. This second part will enrol 12 subjects. These subjects will receive fluconazole 800 mg daily for one day (Day 1) and 400 mg daily orally for 4 days (Days 2 to 5) in combination with F901318 which will be given in a dose of up to 4 mg/kg IV bid for one day (Day 1) followed by 7 doses of intravenous F901318 up to 2.5 mg/kg bid (Days 2 to 5). Pharmacokinetic profiles of F901318 and fluconazole will be obtained during dosing and over a 72-hour period following the final dose of both compounds.