Pemetrexed
Brand names: Alimta
Pemetrexed is a specialist intravenous antifolate cytotoxic agent used in the treatment of non-squamous non-small cell lung cancer and malignant pleural mesothelioma.
ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.
Clinical monograph
How it works
It is a multi-targeted antifolate that inhibits several folate-dependent enzymes involved in purine and pyrimidine synthesis, disrupting DNA and RNA production and causing cell death.
Prescribing in practice
- Folic acid and vitamin B12 supplementation must be given before and throughout treatment to reduce severe haematological and gastrointestinal toxicity.
- It is renally excreted and should be avoided in significant renal impairment, with caution around nephrotoxic and NSAID drugs that reduce its clearance.
- Myelosuppression is dose-limiting and a corticosteroid is given to reduce skin reactions.
Monitoring
Monitor full blood count and renal function before each cycle and ensure vitamin supplementation is maintained.
Counselling the patient
- Take the folic acid as prescribed and attend appointments for your vitamin B12 injections.
- Report fever or signs of infection promptly and avoid anti-inflammatory painkillers unless approved by your team.
Evidence & guidelines
Use in non-small cell lung cancer and mesothelioma is supported by NICE guidance and pivotal registration trials.
Reference: NICE TA124 (mesothelioma); NICE TA309/TA428 (NSCLC); ESMO; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.