Ketoconazole is known to inhibit the metabolism of cyclosporin through
inhibition of cytochrome P-450. This pharmacological interaction was
used in an 8-year-old renal transplant patient to successfully achieve
therapeutic cyclosporin blood concentrations. The addition of ketocon
azole to the cyclosporin regimen should be considered when difficultie
s are encountered in attaining satisfactory cyclosporin levels.