Pemetrexed (pemetrexed disodium)
Multiple manufacturers (generic); original brand: Alimta by Eli Lilly · Antifolate / Multitargeted Antimetabolite
What is Pemetrexed? Pemetrexed (brand: Alimta) is a multitargeted antifolate chemotherapy approved for non-squamous non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma. It requires vitamin supplementation (folic acid and vitamin B12) to reduce toxicity.
About Pemetrexed
| Brand Name | Pemetrexed |
| Generic / INN | pemetrexed disodium |
| Drug Class | Antifolate / Multitargeted Antimetabolite |
| Manufacturer | Multiple manufacturers (generic); original brand: Alimta by Eli Lilly |
| Administration | Intravenous (IV) infusion |
| FDA Approval | 2004 |
FDA-Approved Uses for Pemetrexed
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Non-squamous NSCLC — initial treatment with cisplatin; maintenance after platinum-doublet; after prior chemotherapy
- Malignant pleural mesothelioma — with cisplatin
How Does Pemetrexed Work?
Pemetrexed inhibits multiple folate-dependent enzymes critical for purine and pyrimidine synthesis, including thymidylate synthase (TS), dihydrofolate reductase (DHFR), and GARFT. By blocking these enzymes simultaneously, it disrupts DNA and RNA synthesis in rapidly dividing cancer cells.
Dosage & Administration
500 mg/m² IV over 10 minutes on Day 1 of each 21-day cycle. MANDATORY premedication: folic acid (400–1000 mcg orally daily starting 7 days before first dose and continuing through treatment) and vitamin B12 (1000 mcg IM every 3 cycles). Dexamethasone (4 mg twice daily for 3 days starting day before) reduces skin rash.
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Myelosuppression — serious and dose-limiting. Renal insufficiency — requires dose reduction or withholding; creatinine clearance ≥45 mL/min required. Vitamin supplementation MANDATORY — failure to supplement folic acid and B12 significantly increases toxicity. NSAIDs with long half-lives should be avoided around pemetrexed administration.
- Severe myelosuppression without vitamin supplementation
- Renal failure
- Radiation recall
- Embryo-fetal toxicity
Common Side Effects
- Fatigue
- Nausea
- Anorexia
- Rash (preventable with dexamethasone)
- Neutropenia
- Anemia
- Mucositis
- Diarrhea
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Reconstituted and diluted solution: stable for 24 hours at 2°C to 8°C (36°F to 46°F) or room temperature.
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Pemetrexed is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Pemetrexed. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part B covers this IV medication when administered in a clinical setting. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Pemetrexed
Pemetrexed is used for non-squamous non-small cell lung cancer (with cisplatin or as maintenance/monotherapy) and malignant pleural mesothelioma (with cisplatin). It is not used in squamous NSCLC.
Pemetrexed inhibits folate metabolism. Without folic acid and B12 supplementation, toxicity (especially hematologic and GI) is significantly worse. These vitamins are mandatory — starting 7 days before the first dose.
Yes. Generic pemetrexed disodium is widely available from multiple manufacturers.
Related Medications & Conditions
Related Medications
Cisplatin · Carboplatin · Keytruda (pembrolizumab) · Gemcitabine
Related Conditions
Non-squamous NSCLC · Malignant pleural mesothelioma · Lung cancer