Condition Deep-Dives 10 min read·Updated 22 July 2026 Clinician-reviewed

Tumour Lysis Syndrome (TLS)

A UK Consultant Nephrologist on tumour lysis syndrome — the metabolic emergency that follows rapid death of malignant cells. Recognise the at-risk patient before the first dose of chemotherapy: hyperuricaemia, hyperkalaemia, hyperphosphataemia, hypocalcaemia and AKI.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 22 July 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

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Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

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Direct answer

TLS is preventable. Stratify every haematology patient as low / intermediate / high risk before chemotherapy. Hydrate generously, use allopurinol or rasburicase appropriately, monitor labs every 4–6 hours during the first 72 hours, and involve nephrology early for dialysis.

Key recommendation: Risk-stratify EVERY patient before chemo (haem-onc + renal protocols).

Quick answer

✓ Best choices

  • Adequate fluids once your team confirms it is safe (often 1.5–2 L/day)
  • Easily digested, nutrient-dense meals during recovery
  • Vegetables, fruit, oats and whole grains as appetite returns
  • Protein in modest portions — typically 0.8–1.0 g/kg/day unless advised otherwise

✓ Foods to limit

  • NSAIDs (ibuprofen, naproxen, diclofenac) — they are nephrotoxic
  • Very salty, processed or ultra-processed foods
  • Alcohol while bloods are still recovering

Key takeaway

TLS is preventable. Stratify every haematology patient as low / intermediate / high risk before chemotherapy. Hydrate generously, use allopurinol or rasburicase appropriately, monitor labs every 4–6 hours during the first 72 hours, and involve nephrology early for dialysis.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Tumour Lysis Syndrome (TLS)

Risk stratification (BSH/BCSH UK guidance)

High Risk

  • Burkitt lymphoma / leukaemia
  • T-cell ALL
  • B-ALL with WBC > 100 × 10⁹/L
  • AML with WBC > 100 × 10⁹/L
  • Bulky high-grade NHL with LDH > 2 × ULN
  • Pre-existing AKI or hyperuricaemia
  • Highly chemo-sensitive disease in pregnancy or pre-existing CKD

Intermediate Risk

  • Other intermediate or high-grade lymphomas
  • AML 25–100 × 10⁹/L
  • ALL with WBC 50–100 × 10⁹/L
  • CLL with high tumour burden treated with venetoclax (specific TLS dosing schedule)

Low Risk

  • Indolent lymphomas (CLL not on venetoclax, follicular)
  • Most solid tumours
  • Multiple myeloma

IMMUNOTHERAPY: bispecifics (blinatumomab), CAR-T, venetoclax — escalating TLS recognition; follow specific drug guidance.

Prevention

All Risk Groups

  • IV 0.9% sodium chloride 2.5–3 L/m²/day starting 24–48 h before chemo
  • Aim urine output > 100 mL/m²/h
  • Stop nephrotoxins (NSAIDs, IV contrast, aminoglycosides where possible)
  • Stop allopurinol-interacting drugs (azathioprine, 6-MP)

LOW RISK: hydration + observation.

INTERMEDIATE RISK: hydration + allopurinol 300 mg/day (adjusted for eGFR, max 600 mg) starting 24–48 h before chemo, continue 7 days.

High Risk / Established Hyperuricaemia

  • Hydration + rasburicase 0.2 mg/kg single dose IV (UK practice often 3 mg or 7.5 mg flat dose for cost — re-dose only if needed and urate rebounds)
  • Check G6PD before rasburicase — haemolytic crisis risk
  • Stop allopurinol while on rasburicase (no additive benefit, may interfere with urate measurement)
  • Process urate samples on ice and assay within 4 h (rasburicase degrades urate ex vivo and falsely lowers result)

DO NOT use urinary alkalinisation routinely — risks calcium phosphate precipitation and is no longer recommended.

Recognition & management of established TLS

Monitoring

  • U&E, urate, phosphate, calcium, magnesium, LDH every 4–6 h for 48–72 h after chemo start
  • Strict fluid balance, hourly urine output
  • ECG monitoring for hyperkalaemia

HYPERKALAEMIA: standard algorithm (calcium gluconate for ECG changes, insulin-dextrose, salbutamol, K+ binders, dialysis if refractory).

Hyperphosphataemia

  • Oral phosphate binders (calcium acetate IF calcium not low, sevelamer if calcium low or normal)
  • Avoid IV calcium unless symptomatic — risk of CaPO₄ precipitation and worse AKI
  • Severe / oliguric → dialysis

Hypocalcaemia

  • Treat only if symptomatic (tetany, seizure, prolonged QTc)
  • Use lowest dose IV calcium that controls symptoms
  • Treat the phosphate first where possible

Hyperuricaemia

  • Rasburicase 0.2 mg/kg (single dose often sufficient)
  • Repeat dose only if urate rebounds and clinical TLS persists

AKI

  • Renal review at first sign
  • Optimise fluid balance
  • Continuous RRT preferred — better phosphate clearance, slower shifts, tolerated in haemodynamic instability
  • Discuss with paediatric or adult nephrology early

Outcomes

  • With early recognition, mortality is low
  • Late-recognised TLS (especially with severe AKI requiring RRT) carries a mortality of 15–20%
  • Most patients who survive recover kidney function
Acute Kidney Injury (AKI)
Related reading: Acute Kidney Injury (AKI).

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Follow the NHS sick-day rules: stop ACE inhibitors, ARBs, NSAIDs and diuretics when dehydrated
  • Re-check eGFR at 3 and 6 months as NICE recommends
  • Tell every clinician you see that you have had AKI

Clinical guidance

TL;DR summary

TLS is preventable. Stratify every haematology patient as low / intermediate / high risk before chemotherapy. Hydrate generously, use allopurinol or rasburicase appropriately, monitor labs every 4–6 hours during the first 72 hours, and involve nephrology early for dialysis.

Key takeaways
  • Risk-stratify EVERY patient before chemo (haem-onc + renal protocols).
  • Hyperkalaemia and AKI kill — monitor closely first 72h.
  • Rasburicase rapidly lowers urate; check G6PD first.
  • Avoid bicarbonate and calcium phosphate co-precipitation.
  • Dialysis is early, not late — call nephrology before crisis.
Kidney Diet & Nutrition Considerations

After acute kidney injury (AKI) the priority is recovery: rehydration, treating the underlying cause, stopping nephrotoxins and giving the kidneys a calm nutritional environment. Once eGFR is recovering, a balanced Mediterranean-style diet with sensible salt, sensible protein and good hydration supports healing — and reduces the risk of AKI tipping into long-term CKD.

Foods to prioritise

  • Adequate fluids once your team confirms it is safe (often 1.5–2 L/day)
  • Easily digested, nutrient-dense meals during recovery
  • Vegetables, fruit, oats and whole grains as appetite returns
  • Protein in modest portions — typically 0.8–1.0 g/kg/day unless advised otherwise

Foods to limit

  • NSAIDs (ibuprofen, naproxen, diclofenac) — they are nephrotoxic
  • Very salty, processed or ultra-processed foods
  • Alcohol while bloods are still recovering

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

Which cancers carry the highest risk of TLS?

Highest-risk: Burkitt lymphoma, T-cell acute lymphoblastic leukaemia/lymphoma, advanced-stage diffuse large B-cell lymphoma with bulky disease or high LDH, and acute leukaemias with white cell counts > 100 × 10⁹/L. Intermediate-risk: most other high-grade lymphomas and acute leukaemias. Solid tumours (especially small-cell lung, germ-cell, and some hepatocellular cancers) are usually low-risk except with very bulky/treatment-responsive disease.

What is the difference between allopurinol and rasburicase?

Allopurinol BLOCKS new urate formation but doesn't lower existing urate; effect takes 1–2 days. Rasburicase is recombinant urate oxidase — it CONVERTS urate to soluble allantoin and rapidly clears existing urate. Rasburicase is preferred for high-risk TLS or established hyperuricaemia, and is contraindicated in G6PD deficiency (haemolysis risk).

How is laboratory vs clinical TLS defined?

Cairo-Bishop laboratory TLS = ≥2 of: urate ≥ 476 µmol/L (or 25% rise), potassium ≥ 6 mmol/L (or 25% rise), phosphate ≥ 1.45 mmol/L adults / ≥ 2.1 children (or 25% rise), calcium ≤ 1.75 mmol/L (or 25% fall) — occurring 3 days before to 7 days after cytotoxic therapy. Clinical TLS = laboratory TLS plus AKI, arrhythmia, seizure or sudden death.

When is dialysis needed?

Dialysis is needed for: hyperkalaemia refractory to medical therapy, severe symptomatic hyperphosphataemia, severe oliguric AKI, symptomatic hypocalcaemia attributable to hyperphosphataemia (cannot give IV calcium safely until phosphate falls), and volume overload. Continuous renal replacement therapy is preferred in unstable patients because of better phosphate clearance and slower fluid shifts.

What should I eat to recover from acute kidney injury?

Most adults recovering from AKI do best on a balanced Mediterranean-style diet with adequate hydration (once your team confirms it's safe), moderate protein (around 0.8–1.0 g/kg/day), lower salt, and avoidance of NSAIDs. Your renal team will give you personalised fluid and protein targets based on your recovery.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK guidance

Aligned with British Society for Haematology TLS guidelines, UK Kidney Association AKI guidance and NICE TA recommendations for rasburicase and venetoclax dosing.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Joint haem-onc + renal pathway

Practical UK pathway for risk stratification, rasburicase use, monitoring schedules and dialysis triggers.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • No Added Potassium
  • No Added Magnesium
  • No Added Phosphorus
  • No Added Iron
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
Subscribe & Save — £20.39/monthCheck your current multivitamin

✓ Free UK tracked delivery  ·  ✓ Delivered every 30 days  ·  ✓ Pause or cancel anytime  ·  ✓ Never run out

ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

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View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

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