How should antirejection (immunosuppressive) medications be managed in a patient who is NPO (nothing by mouth) for a procedure?

Management of Antirejection Medications in NPO Patients

Continue all immunosuppressive medications without interruption when patients are NPO for procedures, using intravenous or alternative routes as needed, as even brief interruptions risk acute rejection. 1

Core Principle: Never Stop Immunosuppression

Immunosuppression management remains the primary responsibility of the transplant center and requires lifelong maintenance after solid organ transplantation 1. The risk of acute rejection from interrupted immunosuppression far outweighs the inconvenience of alternative administration routes 1, 2.

Route Conversion Strategy

For Calcineurin Inhibitors (Tacrolimus/Cyclosporine)

• Convert oral to intravenous formulations at approximately 1:4 ratio (IV dose = 25% of oral dose) for tacrolimus, given every 12 hours 1
• For cyclosporine, use 1:3 ratio (IV dose = 33% of oral dose) administered as continuous infusion or divided doses 1
• Maintain target trough levels identical to oral therapy: tacrolimus 5-15 ng/mL initially, ~5 ng/mL long-term; cyclosporine 200-300 ng/mL initially, 50-150 ng/mL long-term 1
• Critical caveat: Coordinate with transplant center before any conversion, as they monitor drug levels monthly and must adjust dosing 1

For Mycophenolate Mofetil/Mycophenolic Acid

• Administer IV mycophenolate at the same total daily dose as oral formulation, divided into two doses every 12 hours 1
• No dose adjustment needed for route conversion 1
• Continue monitoring for GI effects even with IV administration 1

For Corticosteroids

• Switch oral prednisone to IV methylprednisolone at equivalent or slightly higher doses (prednisone 5 mg = methylprednisolone 4 mg) 1, 3
• Maintain baseline immunosuppression doses; do not reduce steroids during NPO period 3

For mTOR Inhibitors (Sirolimus/Everolimus)

• No IV formulation exists—these patients require either nasogastric tube administration or postponement of NPO status if medically feasible 1
• If procedure cannot be delayed, coordinate with transplant team for temporary substitution strategy 1

Timing Considerations

Short Procedures (<24 hours NPO)

• For procedures where NPO status is brief (morning procedure with resumption of oral intake same day), give morning immunosuppression dose IV 2-4 hours before usual oral timing 1
• Resume oral medications as soon as patient tolerates PO intake 1
• Do not skip doses or "make up" missed doses with double dosing 1

Extended NPO Status (>24 hours)

• Establish IV immunosuppression protocol immediately upon NPO order 1
• Obtain trough levels 12 hours after first IV dose to ensure therapeutic range 1
• Maintain IV route until consistent oral intake restored for at least 24 hours 1

Common Pitfalls to Avoid

• Never hold immunosuppression "just for one day"—acute rejection can develop within 48-72 hours of subtherapeutic levels 1, 2
• Do not assume surgical team will manage immunosuppression—this remains transplant center responsibility even during hospitalization 1
• Avoid empiric dose reductions during NPO period due to concerns about drug interactions with anesthesia; maintain therapeutic levels 1
• Do not restart oral medications until patient demonstrates reliable GI absorption (no vomiting, normal bowel function) 1

Monitoring During NPO Period

• Check trough levels 12 hours after any route conversion 1
• Monitor CBC, renal function, and hepatic function if NPO status extends beyond 48 hours 1
• Watch for signs of acute rejection (fever, organ-specific dysfunction) even with appropriate IV dosing 1

Coordination with Transplant Center

• Notify transplant center immediately when patient becomes NPO 1
• Provide transplant team with procedure details, expected NPO duration, and current medication list 1
• Obtain specific IV dosing recommendations from transplant pharmacist or physician 1
• Send all drug levels directly to transplant center for interpretation 1

The evidence consistently demonstrates that maintaining therapeutic immunosuppression without interruption is non-negotiable for transplant recipients 1, 2, 4. While the specific conversion ratios and monitoring parameters come from transplant management guidelines 1, the overarching principle is clear: find an alternative route, never simply hold these medications 1.