<prompt> Which of the following medications essential for ameliorating the toxicity of pemetrexed:Folinic acid and vitamin B6Folic acid and vitamin B12Vitamin 136 and Vitamin B1,Folic acid and dexamethasone  <response>: Ans. b. Folic acid and vitamin B12 Pemetrexed Toxicity Pemetrexed toxicity mirrors that of methotrexate, with the additional feature of a prominent erythematous and pruritic rash in 40 of patientsQ. Dexamethasone, 4 mg twice daily on days -1, 0 and 1, markedly diminishes this toxicity. Unpredictably, severe myelosuppression with pemetrexed, seen especially in patients with pre-existing homocysteinemia and possibly reflecting folate deficiency, is largely eliminated by concurrent administration of low dosages of folic acid, 350-1000 mgday, beginning 1-2 weeks prior to pemetrexed and continuing while the drug is administered. Patients should receive intramuscular vitamin B12 1 mg with the first dose of pemetrexed to correct possible B12 deficiency. These small doses of folate and B12 do not compromise the therapeutic effects. 