Fludarabine

Crystal / Obstructive Nephropathy — representative incidence ~0.33%.

Direct nephrotoxicity is uncommon; the chief renal risks are tumor-lysis-syndrome AKI during cytoreduction and increased systemic toxicity when the renally cleared drug accumulates in renal impairment. About 60% of the active metabolite 2-F-ara-A is renally eliminated, so renal function directly drives exposure. Reported rate: tumor lysis syndrome in 0.33% — 6,137 patients with intermediate- or high-risk advanced chronic lymphocytic leukemia treated with fludarabine 20-40… (Cheson 1998, PMID 9667245).

Source: Cheson et al., J Clin Oncol 1998

Reported injury signatures: Crystal / Obstructive Nephropathy, Prerenal / Hemodynamic AKI, Electrolyte Disturbance.

1. Crystal / Obstructive NephropathyPrimary
2. Prerenal / Hemodynamic AKISecondary
3. Electrolyte DisturbanceSecondary

Acute (~1–7 days) — Tumor-lysis AKI within days of starting therapy.

• Renal impairment (drug accumulation; dose-adjust, avoid if CrCl <30)
• High tumor burden CLL/lymphoma
• Volume depletion / high baseline uric acid
• Older age

• Dose-adjust for creatinine clearance (reduce ~20% for CrCl 30-70; avoid below 30)
• TLS prophylaxis with hydration and allopurinol or rasburicase

• Serum creatinine/CrCl at baseline and across cycles (drives dosing)
• TLS panel (uric acid, K, phosphate, calcium) early in high-burden disease
• CBC and neurologic status (accumulation-related toxicity)

• Lichtman Cancer Invest 2002 - prospective renal-impairment PK/dose-adjustment study (~60% renal elimination of 2-F-ara-A)
• FCR first-line CLL experience (Bouvet Haematologica 2012) - dose reductions including for renal impairment
• Marotta Haematologica 2000 - fludarabine CLL therapy complicated by TLS with transient severe renal impairment

• Always dose fludarabine to CrCl - it accumulates in renal impairment and full dosing below CrCl 30 risks severe, sometimes fatal, neurotoxicity.
• The renal injury you see is usually TLS, not tubular toxicity - prophylax in high-burden CLL/lymphoma.
• Roughly 60% of the active metabolite is renally cleared, so the kidney is the dominant determinant of exposure.

Each recommendation below is this atlas's faithful summary of the source, not a quotation from it — follow the PubMed link for the wording the society published. Summaries may be superseded; consult the current full text and individualize to the patient.

• ADQI (2026) — Conventional cytotoxic chemotherapy-associated nephrotoxicity: consensus report of the 34th Acute Disease Quality Initiative (ADQI) WorkgroupCisplatin is identified as a leading cytotoxic nephrotoxin; the workgroup details preventive measures (adequate isotonic hydration, correction of volume depletion, avoidance of concurrent nephrotoxins, attention to electrolyte/magnesium wasting) and management of cisplatin-associated AKI, with a research agenda for knowledge gaps.Kidney Int · PMID 41881107
• ADQI (2026) — The nephrotoxic effects of anti-cancer therapies: consensus report of the 34th Acute Disease Quality Initiative workgroupProvides expert-based statements (modified Delphi) on preventing and managing cisplatin/platinum-associated AKI, including isotonic IV hydration, attention to volume status and concomitant nephrotoxins, and incorporates evidence that IV magnesium supplementation may reduce cisplatin-associated AKI; emphasizes risk stratification and standardized AKI definitions.Nat Rev Nephrol · PMID 41361704
• SIRM (2022) — SIRM-SIN-AIOM: appropriateness criteria for evaluation and prevention of renal damage in the patient undergoing contrast medium examinations-consensus statements from Italian College of Radiology (SIRM), Italian College of Nephrology (SIN) and Italian Association of Medical Oncology (AIOM)Recommends eGFR-based renal risk assessment and pre/post-contrast isotonic saline or sodium bicarbonate hydration; advises maintaining a 5-7 day interval between iodinated contrast administration and cisplatin in cancer patients to reduce additive nephrotoxicity.Radiol Med · PMID 35303246
• KDIGO (2020) — KDIGO Controversies Conference on onco-nephrology: understanding kidney impairment and solid-organ malignancies, and managing kidney cancerIdentifies platinum compounds (especially cisplatin) as leading cytotoxic causes of acute tubular injury, AKI, and electrolyte/magnesium wasting; calls for interdisciplinary onco-nephrology care, accurate GFR estimation, and individualized drug dosing in patients with reduced kidney function.Kidney Int · PMID 33126977
• KDIGO (2020) — KDIGO Controversies Conference on onco-nephrology: kidney disease in hematological malignancies and the burden of cancer after kidney transplantationAddresses chemotherapy-associated AKI/CKD in hematologic cancer, GFR estimation and chemotherapy dosing in patients with reduced kidney function, and management priorities and research gaps for onco-nephrology care.Kidney Int · PMID 33276867
• ADDIKD (2025) — Integrating International Consensus Guidelines for Anticancer Drug Dosing in Kidney Dysfunction (ADDIKD) into everyday practiceProvides GRADE-based, drug-specific dose-adjustment recommendations for anticancer agents in kidney dysfunction (illustrated for methotrexate, cisplatin, carboplatin and nivolumab); the recommendations build on Part 1's standardised CKD-EPI eGFR assessment rather than Cockcroft-Gault creatinine clearance.EClinicalMedicine · PMID 40290844
• ADDIKD (2025) — Aligning kidney function assessment in patients with cancer to global practices in internal medicineThree consensus recommendations: assess kidney function by GFR (measured GFR or CKD-EPI eGFR), classify it using KDIGO categories, and use this uniform approach to dose anticancer drugs — moving cancer medicine away from Cockcroft-Gault estimated creatinine clearance.EClinicalMedicine · PMID 40290845
• ADDIKD (2025) — A methodology for determining dosing recommendations for anticancer drugs in patients with reduced kidney functionEstablishes that, where RCT evidence is lacking, anticancer drug dosing recommendations in kidney dysfunction should be derived by critically appraising observational literature via GRADE combined with structured international multidisciplinary consensus voting.EClinicalMedicine · PMID 40290846
• KDIGO (2013) — Diagnosis, evaluation, and management of acute kidney injury: a KDIGO summary (Part 1)Defines/stages AKI by serum creatinine and urine output; emphasizes avoiding nephrotoxins, maintaining euvolemia/perfusion, dose-adjusting drugs to kidney function, and monitoring high-risk patients — the framework applied to nephrotoxic anti-cancer agents.Crit Care · PMID 23394211
• KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknownsEvaluate and risk-stratify CKD, manage to delay progression and its complications, and practise explicit medication management and drug stewardship — the framework the atlas's G1–G5 eGFR banding and every renal dose-adjustment recommendation sit inside. Because the guideline excludes dialysis and transplant recipients by its own statement of scope, its recommendations do not carry to those settings, where this atlas's dialyzability and post-transplant guidance rests on other sources.Kidney Int · PMID 38519239
• KDIGO (2021) — Executive summary of the KDIGO 2021 Guideline for the Management of Glomerular DiseasesProvides the staging/treatment framework for drug-associated glomerular lesions (e.g., bisphosphonate- and interferon-related collapsing FSGS, VEGF-inhibitor podocytopathy/proteinuria), including immunosuppression and supportive RAAS-blockade strategies.Kidney Int · PMID 34556300
• KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of ANCA-Associated VasculitisUpdates immunosuppressive induction (rituximab/cyclophosphamide), incorporates avacopan and lower-dose or glucocorticoid-sparing regimens — the management framework for drug- and checkpoint-inhibitor-associated ANCA/pauci-immune glomerulonephritis.Kidney Int · PMID 38388147
• KDIGO (2024) — Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of Lupus NephritisUpdates first-line lupus nephritis therapy to combination immunosuppression with the addition of belimumab or a calcineurin inhibitor (voclosporin) — informs management of immune-complex/lupus-like glomerulonephritis encountered with immunotherapy.Kidney Int · PMID 38182299
• KDIGO (2025) — Executive summary of the KDIGO 2025 Clinical Practice Guideline for the Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV)Encourages liberal kidney biopsy and stricter proteinuria control (<0.5 g/d, ideally <0.3 g/d) with RAAS blockers, SGLT2 inhibitors, and targeted-release budesonide — the framework for IgA-dominant glomerular lesions, including those triggered by immune-modulating cancer therapy.Kidney Int · PMID 40975525