Folate Antagonists

Pemetrexed disodium (Alimta) disrupts cell growth by blocking folic acid. Some metabolic processes causing cells to reproduce are dependent on folic acid. 

• Who should not use these medications:
  
  
  • Individuals with an allergy to the drug or any of its components
  
  
  
  • Individuals with moderate-to-severe kidney impairment


• Use:
  
  
  • Pemetrexed disodium is given as an IV infusion over 10 minutes on the first day of each 21-day chemotherapy cycle.
  
  
  
  • Folic acid and vitamin B-12 supplementation are required before pemetrexed disodium.
  
  
  
  • Corticosteroids are also administered to decrease the incidence of rash. 
  
  
  
• Drug or food interactions: Probenecid may decrease the ability of the kidneys to excrete pemetrexed disodium, thereby causing increased blood levels and toxicity. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) or naproxen (Aleve), should not be administered for 2 days before and 2 days after receiving pemetrexed disodium because they may decrease the drug’s excretion from the body and increase the risk for toxicity. Individuals with kidney impairment should not take any NSAIDs at any time.



• Side effects: A doctor will check a person's blood at regular visits while that person is taking pemetrexed disodium. The doctor should be contacted immediately if any of the following side effects occur:
  
  
  • Rash
  
  
  
  • Unusual bruising
  
  
  
  • Bleeding
  
  
  
  • Fever
  
  
  
  • Sore throat
  
  
  
  • Sores in the mouth