Platinum Compounds in Oncology

Also written as Cisplatin, Carboplatin, Oxaliplatin.

Platinum agents are alkylating chemotherapeutics that cross‑link DNA, blocking tumour cell replication. Their use in low‑resource settings hinges on recognising toxicity, managing side effects, and adapting monitoring when laboratory tests are limited.

Definition and diagnosis

Platinum compounds are metal‑based drugs that form covalent bonds with DNA, creating cross‑links that prevent replication. Diagnosis of exposure is clinical; laboratory confirmation is rarely required.

• Cisplatin – first‑line for testicular, ovarian, bladder, head and neck cancers
• Carboplatin – used where renal toxicity is a concern
• Oxaliplatin – part of FOLFOX for colorectal cancer

Severity and staging

Toxicity is graded by the Common Terminology Criteria for Adverse Events (CTCAE). Grade 3–4 events (e.g., nephrotoxicity, neurotoxicity) necessitate dose reduction or discontinuation.

• Serum creatinine: Assess renal function; rise >1.5× baseline indicates nephrotoxicity
• Serum potassium: Hypokalaemia can worsen cardiac arrhythmias
• Peripheral neuropathy assessment: Onset of tingling/paraesthesia suggests neurotoxicity

• Grade 1–2: mild, manageable with supportive care
• Grade 3–4: severe, may require hospitalization

Causes, most likely first

The primary causes of toxicity are drug properties and patient factors common in low‑resource settings.

• Urine output: Oliguria (<0.5 mL/kg/h) indicates acute kidney injury

• High cumulative dose
• Pre‑existing renal impairment (e.g., HIV nephropathy)
• Concurrent nephrotoxic drugs (e.g., aminoglycosides)
• Malnutrition leading to electrolyte imbalance

How it presents

Patients may develop nausea, vomiting, fever, myalgia, and, with repeated doses, sensorineural hearing loss, peripheral neuropathy, and nephrotoxicity.

• Chronic: numbness in feet, tinnitus, decreased urine output

Investigations

Baseline and periodic monitoring are essential, but many tests may be unavailable. Use clinical judgement and simple bedside tools.

• CBC: Detect myelosuppression; low platelets can cause bleeding
• Serum creatinine: Identify nephrotoxicity; rise >1.5× baseline
• Serum potassium: Prevent arrhythmias; hypokalaemia is common

• Audiometry if available; otherwise ask about hearing changes

Red flags and complications

Certain signs warrant urgent action: severe renal failure, profound neurotoxicity, uncontrolled bleeding, or anaphylaxis.

• Creatinine >2× baseline
• Severe paresthesia with loss of reflexes
• Bleeding from mucosal sites
• Anaphylactic reaction (rash, hypotension)

Management

Treat the underlying toxicity, provide supportive care, and adjust chemotherapy dosing. Avoid drugs that worsen the same organ system.

• Avoid NSAIDs and other nephrotoxic agents

Follow‑up and prevention

Regular monitoring of renal function, electrolytes, and neuro‑sensory status is mandatory. Patient education on reporting symptoms early is key.

• Educate on hydration and early symptom reporting

Often confused with

Other causes of nausea, vomiting, and neuropathy can mimic platinum toxicity.

• Infections (e.g., malaria) – fever, chills

Where results can mislead

Some laboratory values may be falsely normal or misleading in resource‑limited settings.

• Audiometry may not be available; rely on patient history

Questions an examiner may ask

• What is the first step if a patient develops vomiting within 24 h of cisplatin? — Give anti‑emetics and ensure hydration.
• How would you differentiate platinum‑induced neuropathy from diabetic neuropathy in a patient with HIV? — Look for acute onset, stocking‑glove distribution, and absence of glycaemic control issues.
• A patient on cisplatin develops a sudden rise in serum creatinine. What is the immediate management? — Stop the drug, start aggressive hydration, and consider switching to carboplatin.
• Why is carboplatin preferred in patients with pre‑existing renal impairment? — It has a longer half‑life and less nephrotoxicity.
• During a ward round, a patient on oxaliplatin reports tinnitus. What should you do? — Assess hearing, document, and consider dose reduction or discontinuation.
• If a patient cannot afford routine blood tests, what bedside monitoring can you rely on for nephrotoxicity? — Monitor urine output and look for oliguria.

When to seek help

• Severe renal failure (creatinine >2× baseline)
• Uncontrolled bleeding
• Anaphylaxis
• Loss of consciousness or severe neurotoxicity

Quick questions

Why is cisplatin preferred over carboplatin in some cancers?

Cisplatin is more potent but more nephrotoxic; carboplatin is chosen when renal function is compromised.

Can I take NSAIDs while on platinum therapy?

No, NSAIDs worsen renal toxicity and should be avoided.

What is the best way to prevent nephrotoxicity?

Ensure adequate hydration before and after infusion and monitor renal function closely.