pemetrexed disodium hydrate: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
pemetrexed disodium hydrate: clinical details
Prescribing considerations
- Administer only under a clinician experienced in systemic anti-cancer treatment.
- Ensure folic acid and vitamin B12 supplementation and corticosteroid prophylaxis are in place.
- Use is not recommended when creatinine clearance is below the product threshold; review NSAIDs and other renally cleared or nephrotoxic medicines.
- Assess hydration, gastrointestinal toxicity, third-space fluid, previous or planned radiotherapy, cardiovascular risk and vaccination status.
- Discuss contraception and fertility preservation before treatment where relevant.
Contraindications and cautions
- Hypersensitivity to pemetrexed or an excipient.
- Breastfeeding.
- Concurrent yellow fever vaccination.
Monitoring
- Full blood count, including differential white-cell and platelet counts, before administration.
- Renal and hepatic biochemistry before administration, with particular attention to creatinine clearance.
- Clinical assessment for infection, bleeding, mucositis, dehydration, rash, neuropathy and renal toxicity.
- Closer INR monitoring when an oral anticoagulant is continued.
- Watch for radiation pneumonitis or recall reactions in patients with previous or concurrent radiotherapy.
Clinical pharmacology
Pemetrexed inhibits several folate-dependent nucleotide-synthesis enzymes and is retained intracellularly as active polyglutamate forms. Hepatic metabolism is limited; most administered pemetrexed is eliminated unchanged in urine, making renal function a major determinant of exposure.
Formulation and product differences
- The selected product is a clear liquid concentrate requiring aseptic dilution before intravenous administration.
- It is a single-use preparation containing mannitol, acetylcysteine, sodium hydroxide, hydrochloric acid and water for injections.
- It is physically incompatible with calcium-containing diluents such as Ringer's solutions.
- Unopened vials require refrigeration and must not be frozen.
pemetrexed disodium hydrate preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 25 mg/mL
pemetrexed disodium hydrate interactions
The oncology team should review prescribed, over-the-counter and complementary products before treatment.
NSAIDs, including ibuprofen and high-dose aspirin
They may reduce renal elimination of pemetrexed and increase blood, gastrointestinal or other toxicity, particularly when kidney function is impaired.
Nephrotoxic medicines, including aminoglycosides, loop diuretics and ciclosporin
Combined use may delay pemetrexed clearance, so caution and closer renal monitoring may be needed.
Medicines cleared by renal tubular secretion, including probenecid and penicillins
Competition for renal secretion may delay pemetrexed clearance and increase toxicity.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.