Review the kidney transplant tacrolimus monitoring trend.

Quick answer
The rising tacrolimus trough above the target range, along with worsening creatinine, oliguria, and hyperkalemia, points to tacrolimus nephrotoxicity. The priority is to notify the transplant provider before the next dose, as continued dosing could worsen kidney injury.

Why this is correct
Tacrolimus has a narrow therapeutic index. Trough levels above 20 ng/mL are associated with nephrotoxicity, neurotoxicity, and electrolyte disturbances. The patient's trend shows a steady rise in trough and creatinine, with new hyperkalemia and reduced urine output, which are classic signs of toxicity rather than rejection.

Clinical picture
In tacrolimus toxicity, the provider may reduce the dose, hold a dose, or switch to an alternative immunosuppressant. The nurse should not independently adjust the dose or stop monitoring. Hyperkalemia may require urgent treatment, but the first step is to notify the provider who can order appropriate interventions.

Memory hook
Tacrolimus trough target is typically 5-15 ng/mL in the early post-transplant period, but varies by protocol. Creatinine >1.3 mg/dL or a rise of >0.3 mg/dL from baseline suggests acute kidney injury. Potassium >5.0 mEq/L requires prompt attention.

NCLEX decision rule
For any suspected drug toxicity, the nurse must first notify the prescriber before making changes. Do not administer the next dose if the level is toxic unless ordered.

Why the alternatives are wrong
Maintaining the current dose is unsafe because the trough is already above target and renal function is worsening. Giving extra tacrolimus or encouraging grapefruit juice would further increase levels. Stopping all lab monitoring would delay detection of worsening toxicity.