phenobarbital raises toxicity of ifosfamide by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Check. CYP3A4 inducers could boost the metabolism of ifosfamide to its Lively alkylating metabolites.No dosage adjustment for ondansetron is suggested for sufferers on these medicine.Minimal (1)phenobarbital will decrease the extent o