55 - Drugs causing Megaloblastic anemia

1. Phenytoin (anticonvulsant)

2. Primidone (anticonvulsant)

3. Phenobarbitone (anticonvulsant)

4. Sulfasalazine

5. Nitrous oxide
6. Folate antagonists (inhibitors of Dihydrofolate reductase) like Methotrexate, Pentamidine,     Pyrimethamine, Triamterene, Trimethoprim and Cotrimoxazole.
7. Drugs that inhibit DNA synthesis may cause Megaloblastic anemia
    example : 6a. Purine antagonists = 6-Mercaptopurine, Azathioprine.
                   6b. Pyramidine antagonists = 5 FU, Cytosine arabinoside .

                   6c. Others = Hydroxyurea, acyclovir and zidovudine (AZT, Azidothymidine).
8. Nitrofurantoin (less well documented)
9. Tetracycline (less well documented)
10. Anti-Tuberculosis drugs (less well documented)