eGFR-based dose modifications for CKD stages 1–5 and dialysis. Antibiotics, antihypertensives,
diabetic drugs, analgesics and common ward medications — with Nigeria and Ghana availability context.
BNF 2024 · Renal Drug Handbook 2022 · KDIGO CKD Guidelines 2024. Offline-capable.
For qualified healthcare professionals only.
eGFR/CrCl estimates are population-based and can be unreliable in unstable AKI/rapidly changing creatinine, pregnancy, severe malnutrition, oedema, amputees, extremes of muscle mass or body size, and children unless a paediatric equation is used. Use clinical judgement alongside eGFR. Always check the most recent creatinine and urine output before prescribing renally-cleared drugs.
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Chronic kidney disease (CKD) is increasingly prevalent across sub-Saharan Africa, driven by hypertension, type 2 diabetes, sickle cell nephropathy, and endemic infections including schistosomiasis and HIV-associated nephropathy. Many essential medicines are renally cleared and require dose adjustment to avoid drug accumulation, toxicity, and further nephrotoxicity. Failure to dose-adjust in CKD is a leading cause of preventable drug toxicity in African clinical settings — particularly with aminoglycosides, NSAIDs, metformin, and renally-cleared antibiotics. This calculator uses eGFR-based thresholds aligned with KDIGO CKD staging and references the British National Formulary, WHO Model Formulary, and Renal Drug Handbook (Ashley & Dunleavy).
Frequently Asked Questions
Two main equations are used. The Cockcroft-Gault (CG) formula — [(140 − age) × weight × 0.85 if female] ÷ [serum creatinine (μmol/L) × 0.814] — estimates creatinine clearance and is most commonly used for drug dosing. The CKD-EPI equation is more accurate for eGFR staging but less commonly used for individual drug dosing calculations.
Key drugs requiring reduction: aminoglycosides (reduce dose or extend interval), vancomycin (reduce dose, monitor levels), metformin (stop at eGFR <30), direct oral anticoagulants (all require adjustment), trimethoprim-sulfamethoxazole (avoid at eGFR <15), acyclovir (reduce dose and frequency), most beta-lactam antibiotics at eGFR <30.
Key thresholds used in drug dosing: eGFR <60 mL/min/1.73m² — some drugs need dose review. eGFR <30 — most renally cleared drugs need significant reduction. eGFR <15 — many drugs are contraindicated; dialysis patients require specific guidance. Individual drug data always supersedes general thresholds — check each drug separately.
Drugs that are highly water-soluble, have low protein binding, small volume of distribution, and low molecular weight are most readily removed by haemodialysis. Clinically significant examples requiring supplementary dosing after dialysis include: aminoglycosides (gentamicin, amikacin), acyclovir, certain penicillins and cephalosporins, metronidazole, lithium, and vancomycin (HD-removed variably). Drugs not significantly removed by dialysis include: most fluoroquinolones, macrolides, warfarin, phenytoin, and most antifungals. Always check a renal drug dosing reference after each dialysis session for renally-adjusted drugs.
eGFR (estimated glomerular filtration rate, mL/min/1.73 m²), calculated by CKD-EPI or MDRD, is normalised for body surface area and is preferred for classifying CKD stages. Creatinine clearance (CrCl, mL/min), calculated by Cockcroft-Gault, is NOT normalised for BSA and is the preferred metric for drug dosing because drug elimination correlates with actual, not BSA-adjusted, renal function. For drug dosing in extremes of body weight (obese or cachectic patients), use adjusted body weight in the Cockcroft-Gault formula. Most renal drug dosing tables and SPC documents use CrCl rather than eGFR.
Related calculators
To choose the most appropriate antibiotic for a patient with CKD, use the Antibiotic Selector.