This is an open-label (all people know the identity of the intervention), multicenter (conducted in more than 1 center) and uncontrolled (no competitive drugs involved) study. Participants with SFI will receive treatment with ITCZ oral solution or switch treatment from intravenous (into a vein) infusion of itraconazole (ITCZ-intravenous) to ITCZ oral solution as per Investigator's discretion. All the participants with FN suspected of fungal infection will receive the switch treatment from ITCZ- intravenous to ITCZ oral solution. The study will include 3 periods: Pre-observation period (7 days), Treatment period (85 days for ITCZ oral solution monotherapy and 99 days for switch treatment) and Follow-up observation period (30 days). The participants who receive ITCZ oral solution monotherapy will receive ITCZ oral solution without ITCZ-intravenous in the dose range of 20 milliliter (ml) per day to 40 ml per day for 12 weeks (85 days) and those on the switch treatment will receive 400 milligram (mg) per day ITCZ-intravenous twice for first 2 days followed by 200 mg per day ITCZ-intravenous up to 14 days and then they will be administered treatment as per ITCZ oral solution monotherapy. Efficacy will primarily be evaluated by assessing the pharmacokinetics. Participants' safety will be monitored throughout the study.