Drug Dosing in CKD and Dialysis — Intermediate

Renally cleared drugs can accumulate when filtration falls. Maintenance dose, interval, or both should be adjusted using an appropriate kidney-function estimate, while indication, severity, drug levels, and clinical response are considered. A creatinine rise is not by itself a reason to stop needed treatment.

Dialysis removes drugs most efficiently when they remain in the intravascular space, are poorly protein bound, and have a relatively small volume of distribution. Highly protein-bound or extensively distributed drugs are generally less dialyzable.

A modest early creatinine rise can reflect reduced intraglomerular pressure after efferent arteriolar dilation. The patient still needs review for volume depletion, NSAIDs, renal artery disease, and hyperkalemia; progressive deterioration is not automatically acceptable.

Medication reconciliation is central to AKI evaluation. NSAIDs, renin-angiotensin system blockers, diuretics, contrast exposure, antimicrobials, and new over-the-counter products may contribute through hemodynamic, tubular, interstitial, or obstructive mechanisms.

Creatinine production depends partly on muscle mass. In cachexia, amputation, or severe frailty, a low creatinine can overestimate filtration, so drug dosing should incorporate clinical context and, when needed, measured clearance or another validated estimate.

If dialysis removes a clinically important fraction of a drug, administration after the session or a post-dialysis supplement may be needed. The decision depends on the drug, dose, dialysis prescription, residual kidney function, and therapeutic target.

Narrow-therapeutic-index drugs require individualized dosing and close monitoring because small concentration changes can cause toxicity or treatment failure. Kidney function trends, interacting drugs, timing of levels, and clinical status all matter.

Some sulfonylureas or active metabolites accumulate as kidney function declines, producing prolonged hypoglycemia. Therapy should be reassessed, alternative agents considered, and recurrent hypoglycemia monitored rather than treated as a transient isolated event.

Contrast decisions should be individualized. Baseline kidney function, AKI, hemodynamic status, diabetes, volume depletion, nephrotoxins, contrast volume, and urgency of imaging should be considered; unnecessary exposure should be avoided but needed studies should not be withheld reflexively.

Peritoneal dialysis clearance varies with modality, dwell time, membrane transport, drug characteristics, and residual kidney function. Drug-specific guidance and clinical monitoring are preferable to applying a hemodialysis schedule or normal-kidney dose.