pemetrexed disodium heptahydrate: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
pemetrexed disodium heptahydrate: clinical details
Prescribing considerations
- Use only under supervision of a clinician experienced in anticancer chemotherapy.
- Ensure folic acid and vitamin B12 supplementation and corticosteroid premedication are prescribed to reduce toxicity.
- Review renal function, interacting medicines, previous or planned radiotherapy, fertility and reproductive risks.
- Significant toxicity may require treatment withholding or modification according to the product information.
Contraindications and cautions
- Hypersensitivity to pemetrexed or an excipient.
- Breastfeeding.
- Concomitant yellow-fever vaccine.
- Use is not recommended when creatinine clearance is below the SmPC threshold because evidence is insufficient and renal elimination is central to clearance.
Monitoring
- Full blood count with differential and platelets before administration.
- Renal and hepatic function before administration and more closely when clinically indicated.
- Assess infection, bleeding, mucositis, gastrointestinal toxicity, rash, neuropathy and infusion-site reactions.
- Evaluate new respiratory symptoms for pneumonitis, particularly around thoracic radiotherapy.
Clinical pharmacology
A multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase and glycinamide ribonucleotide formyltransferase. Intracellular polyglutamation increases retention and enzyme inhibition. Elimination is predominantly renal, largely as unchanged pemetrexed.
Formulation and product differences
- The selected product is a ready-to-use solution in a single-use, non-PVC infusion bag rather than a powder or concentrate requiring preparation.
- It should not be mixed with other medicines or have additives introduced into the bag.
- The formulation contains a clinically relevant amount of sodium, which may matter for patients requiring sodium restriction.
pemetrexed disodium heptahydrate preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 5 mg/mL, 6 mg/mL, 6.5 mg/mL, 7 mg/mL, 7.5 mg/mL, 8 mg/mL, 8.5 mg/mL, 9 mg/mL, 10 mg/mL, 11 mg/mL, 100 mg, 500 mg, 1000 mg
pemetrexed disodium heptahydrate interactions
A complete medication and vaccination review is required because reduced renal clearance can increase pemetrexed toxicity.
NSAIDs, including ibuprofen and higher-dose aspirin
They may reduce pemetrexed elimination and increase bone-marrow or gastrointestinal toxicity, particularly with impaired kidney function.
Nephrotoxic medicines, including aminoglycosides, loop diuretics, platinum compounds and ciclosporin
Combined use may delay pemetrexed clearance; caution and closer renal monitoring may be needed.
OAT3 inhibitors, including probenecid, penicillins and proton-pump inhibitors
These may delay renal clearance of pemetrexed and increase exposure.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.