I. Dose Adjustment Methods

A. Maintenance Dose
In patients with kidney insufficiency, the dose may be adjusted using the following methods:

1. 1. Lengthen intervals between individual doses, keeping normal dose.
2. 2. Reduce number of individual doses, keeping interval between doses normal. For this method, percentage of usual dose is shown. For some medications and indications, specific dosing is provided.
3. 3. A combination of the above

NOTE: Dose adjustments in these tables do not apply to patients in the neonatal period. For neonatal renal dosing, please consult a neonatal dosage reference (see Chapter 18). Dose modifications given are only approximations and may not be appropriate for all patients or indications. Recommendations for dose adjustments with reduced glomerular filtration rate (GFR) are often based on chronic kidney disease populations; it may not be appropriate to extrapolate these adjustments to acute kidney injury. Each patient must be monitored closely for signs of drug toxicity, and serum levels must be measured when available; drug doses and intervals should be adjusted accordingly. When in doubt, always consult a pharmacist and/or nephrologist who has expertise in renal dosing.

B. Dialysis
General recommendations are provided when available. However, factors such as patient age, indication for use, residual native kidney function, specific peritoneal dialysis (PD) or intermittent hemodialysis (IHD) prescription, and so on, will affect the medication dosing needs of each individual patient. Doses for IHD generally assume standard, thrice-weekly dialysis sessions with limited residual native kidney function. Consult with a nephrologist or pharmacist who is familiar with medication dosing in dialysis before prescribing medications for a dialysis patient.

C. Glomerular Filtration Rate Estimation
Estimated GFR (eGFR) in children may be calculated using the bedside CKiD equation¹: 0.413 × height (cm) / serum creatinine. Changes in serum creatinine lag changes in kidney function, and estimations may be inaccurate if serum creatinine is not at steady state. Additionally, in patients with reduced muscle mass or malnutrition, this equation may overestimate GFR. Other information such as trend in serum creatinine or presence of oliguria (<0.5 mL/kg/hr urine × 6 hr) or anuria may help interpret the appropriateness of the calculated eGFR. When in doubt, consult a nephrologist to help determine an accurate eGFR range for medication dosing.