Pemetrex 500 mg contains pemetrexed, a chemotherapy medication used in the treatment of certain types of lung cancer and mesothelioma. It is classified as an antifolate antineoplastic agent and works by disrupting essential cell functions in cancer cells, ultimately stopping their growth and replication.

This medication is administered through an intravenous infusion and is often used in combination with other chemotherapy drugs for enhanced effectiveness. Pemetrex is an important part of treatment plans where targeted or immunotherapy may not be suitable.

Mechanism of Action

Pemetrexed interferes with the folate-dependent metabolic processes that are crucial for DNA and RNA synthesis in rapidly dividing cells. It works by inhibiting multiple enzymes involved in folate metabolism, including:

• Thymidylate synthase

• Dihydrofolate reductase

• Glycinamide ribonucleotide formyltransferase

By blocking these enzymes, pemetrexed prevents cancer cells from producing the building blocks they need to grow and divide. As cancer cells are more reliant on these rapid processes than normal cells, they are more sensitive to pemetrexed’s effects.

Uses

Pemetrex 500 mg is used to treat the following conditions:

• Malignant pleural mesothelioma, usually in combination with cisplatin, especially in patients who are not candidates for surgery

• Non-small cell lung cancer (NSCLC), particularly non-squamous types, either alone or with other agents like platinum-based drugs

• It may also be used as maintenance therapy after initial successful treatment, helping delay cancer progression

  Adverse Effects

  Like many chemotherapy agents, pemetrexed can cause side effects, which vary in severity depending on individual tolerance, treatment duration, and combination with other therapies.

  Common Side Effects

  • Fatigue and weakness

  • Nausea and vomiting

  • Loss of appetite

  • Low blood counts, leading to anemia, infections, or bleeding tendencies

  • Skin rash or peeling

  • Mouth sores or inflammation