Folic acid allergic reactions

Few adverse reactions are associated with the administration of folic acid and leucovorin. Rarely, parenteral administration may result in allergic hypersensitivity. 

Folic acid is also well tolerated. Some nonspecific adverse effects include allergic reactions, flushing, malaise, and rash. Folic acid has been reported to decrease phenytoin levels by inducing its metabolism. 

Folic acid bad taste and nausea, rash, and allergic reactions... 

Pemetrexed is chemically similar to folic acid. It inhibits three enzymes used in purine and pyrimidine synthesis - thymidylate synthetase, dihydrofolate reductase, and glycinamide ribonucleotide formyl transferase. By inhibiting the formation of precursor purine and pyrimidine nucleotides, pemetrexed prevents the formation of DNA and RNA. In 2004 it was approved for treatment of malignant pleural mesothelioma and as a second-line agent for the treatment of non-small cell lung cancer. Adverse effects include gastrointestinal complaints, bone marrow suppression, alopecia, allergic and neurotoxic reactions. 

Like oral iron, parenteral iron is used too widely. When iron is truly needed, oral administration is generally preferable (9). Intractable gastrointestinal intolerance to oral formulations, hyperemesis in pregnancy, very severe blood loss, and possibly ulcerative colitis are some of the few valid indications for parenteral iron. A low ironbinding capacity (for example due to prior saturating iron therapy or malnutrition), folic acid deficiency, and an allergic constitution predispose the patient to adverse reactions to parenteral iron. Iron injections have been reported to provoke hemolytic anemia in cases of paroxysmal nocturnal hemoglobinuria. 

Vitamin B12 is virtually nontoxic, even at high oral or injected doses excessive amounts are rapidly excreted. However, occasionally allergic responses to injected vitamin B12 occur (Fisher 1973), and adverse reactions to the combined administration of large injected doses of vitamin B12 and of oral vitamin C have been reported (Schrauzer 1979). Vitamin B12 is required for methionine biosynthesis and functions in conjunction with folic acid as the intermediate carrier of the methyl group. In its coenzyme form (5 -deoxyadenosylcobala-min), it is required for the conversion of methylmalonyl-CoA to succinyl-CoA. (Friedrich 1987). Bacteria utilize vitamin Bjj or its coenzyme in certain dehydrases, deaminases, and in methane biosynthesis. 

Is more likely to cause thrombocytopenia Is more likely to elicit an allergic reaction Is more likely to prevent fevers in neutropenic patients Stimulates production of a wider variety of hematopoietic stem cells 8. An important biochemical consequence of vitamin B,2 deficiency is accumulation of (A) Dihydrofolate dTMP Folic acid... 

In conclusion, in spite of the extensive use of folic acid since its synthesis in 1945, only six vague reports about a possible allergy to folic acid have been published. Conclusive evidence for a real allergic pathogenesis of the observed reactions, however, has not been presented. 

---