Folic Acid has 33 known drug interactions based on U.S. FDA drug labeling data. Of these, 1 are contraindicated combinations that should be avoided entirely. 15 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Levodopa, Aspirin, Barbiturates. Patients taking Folic Acid should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 33
- Contraindicated
- 1
- Major
- 15
- Moderate
- 17
Contraindicated (1)
- Folic Acid + Levodopa— Not recommended and should not be given together as folic acid antagonizes the action of levodopa.
Major (15)
- Folic Acid + Aspirin— Possibility of increased bleeding due to folic acid interaction with anticoagulants.
- Folic Acid + Barbiturates— Barbiturate administration causes folate deficiency through increased loss or metabolic interference.
- Folic Acid + Carbamazepine— Enzyme-inducing anticonvulsant that decreases folate availability through increased hepatic metabolism and inhibition of…
- Folic Acid + Clopidogrel— Possibility of increased bleeding due to folic acid interaction with anticoagulants.
- Folic Acid + Heparin— Possibility of increased bleeding due to folic acid interaction with anticoagulants.
- Folic Acid + Methotrexate— Methotrexate interferes with folate metabolism, resulting in folate deficiency.
- Folic Acid + Methotrexate Sodium— Decreases clinical effectiveness of methotrexate in patients with neoplastic diseases by competing with reduced folates …
- Folic Acid + Nitrofurantoin— Nitrofurantoin administration results in folate deficiency.
- Folic Acid + Pafolacianine Injection— Folic acid may reduce binding of pafolacianine to folate receptors and could reduce detection of lesions. Avoid administ…
- Folic Acid + Phenobarbital— Enzyme-inducing anticonvulsant that decreases folate availability through increased hepatic metabolism and inhibition of…
- Folic Acid + Phenytoin— Folic acid antagonizes the anticonvulsant action of phenytoin, potentially requiring increased phenytoin doses to mainta…
- Folic Acid + Primidone— Primidone administration causes folate deficiency through increased loss or metabolic interference.
- Folic Acid + Pyrimethamine— Pyrimethamine administration results in folate deficiency.
- Folic Acid + Triamterene— Antifolate agent that directly inhibits dihydrofolate reductase, decreasing formation of active folate derivatives.
- Folic Acid + Trimethoprim— Antifolate agent that directly inhibits dihydrofolate reductase, decreasing formation of active folate derivatives.
Moderate (17)
- Folic Acid + Acetazolamide— Acetazolamide may increase the effects of other folic acid antagonists.
- Folic Acid + Acetazolamide Extended-Release— Acetazolamide may increase the effects of other folic acid antagonists.
- Folic Acid + Acetazolamide Sodium— Acetazolamide may increase the effects of other folic acid antagonists.
- Folic Acid + Antacids Containing Calcium— Antacids impair gastrointestinal folate uptake through pH elevation.
- Folic Acid + Cholestyramine Light— Cholestyramine impairs gastrointestinal folate uptake through binding of dietary folate.
- Folic Acid + Colestipol— Colestipol impairs gastrointestinal folate uptake through binding of dietary folate.
- Folic Acid + Cycloserine— Cycloserine reduces folate utilization through metabolic disruption.
- Folic Acid + Fosphenytoin Sodium— May decrease phenytoin serum levels; dose adjustment may be required.
- Folic Acid + H2 Blockers— H2 blockers impair gastrointestinal folate uptake through pH elevation and transporter inhibition.
- Folic Acid + Isoniazid— Isoniazid reduces folate utilization through metabolic disruption.
- Folic Acid + Nitrous Oxide— Nitrous oxide indirectly decreases folate activity by inactivating vitamin B12 and downstream methylation pathways.
- Folic Acid + Oral Contraceptives— Oral contraceptives increase folate turnover and urinary loss.
- Folic Acid + Pentamidine— Pentamidine impairs gastrointestinal folate uptake through mechanisms affecting folate absorption.
- Folic Acid + Phenytoin Sodium— May decrease phenytoin serum levels; monitoring of phenytoin levels recommended.
- Folic Acid + Sulfasalazine— Reduced absorption of folic acid reported when administered concomitantly with sulfasalazine.
- Folic Acid + Tetracycline— Folic acid may interfere with the absorption and effectiveness of antibiotic tetracycline.
- Folic Acid + Valproate— Valproate reduces intestinal folate absorption and interferes with folate-dependent metabolic pathways.