How is tacrolimus administered?
Tacrolimus can be given by mouth (PO), intravenously (IV), or sublingual. Oral dosing, when initially given in combination with MMF or MPA, is 0.1 mg/kg per day. It is important to know if the tacrolimus is immediate release (twice daily dosing) or extended release (once daily dosing); the ratio is 1:1. If IV tacrolimus is used the dose is 0.03 to 0.05 mg/kg per day by continuous infusion. The conversion ratio from oral dosing to IV dosing is roughly about 4:1. The maximum IV dose is 4 mg daily. However, the levels are difficult to follow and can be labile with IV dosing. Sublingual dosing is about 50% of oral dosing. If a patient is nothing by mouth (NPO), sublingual is preferable to IV dosing. In a situation where the patient cannot be appropriately dosed, the immunosuppression plan should be discussed with a transplant specialist.
