Fluorouracil has 16 known drug interactions based on U.S. FDA drug labeling data. 8 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Allopurinol, Allopurinol Sodium, Leucovorin Calcium. Patients taking Fluorouracil 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
- 16
- Major
- 8
- Moderate
- 8
Major (8)
- Fluorouracil + Allopurinol— Allopurinol may decrease anti-tumor activity due to suppression of phosphorylation of 5-fluorouracil. Concomitant admini…
- Fluorouracil + Allopurinol Sodium— Allopurinol may decrease anti-tumor activity by suppressing phosphorylation of 5-fluorouracil. Avoid concomitant adminis…
- Fluorouracil + Leucovorin Calcium— Leucovorin may enhance the toxicity of fluorouracil.
- Fluorouracil + Levoleucovorin— Levoleucovorin increases toxicity of fluorouracil. Do not initiate therapy until gastrointestinal toxicity symptoms reso…
- Fluorouracil + Levoleucovorin Calcium— Levoleucovorin increases the toxicity of fluorouracil. Do not initiate/continue therapy in patients with gastrointestina…
- Fluorouracil + Levoleucovorin Injection— Leucovorin products increase toxicity of fluorouracil. Do not initiate or continue therapy if gastrointestinal toxicity …
- Fluorouracil + Oxaliplatin— Prolonged prothrombin time and INR occasionally associated with hemorrhage reported when used with oxaliplatin, especial…
- Fluorouracil + Warfarin— Elevated coagulation times reported with concurrent use. Fluorouracil or its metabolites may inhibit CYP2C9, increasing …
Moderate (8)
- Fluorouracil + Fosphenytoin Sodium— May increase phenytoin serum levels; monitoring of phenytoin levels recommended.
- Fluorouracil + Irinotecan Hydrochloride— Co-administration reduces SN-38 Cmax by 14% and AUC by 8%. This sequence is used in combination trials and is recommende…
- Fluorouracil + Levothyroxine Sodium— May increase serum thyroxine-binding globulin concentration, resulting in initial transient increase in FT4 followed by …
- Fluorouracil + Liothyronine Sodium— May increase serum thyroxine-binding globulin concentration, altering T3 serum transport. Closely monitor thyroid hormon…
- Fluorouracil + Neomycin Sulfate— Oral neomycin inhibits gastrointestinal absorption of 5-fluorouracil.
- Fluorouracil + Phenytoin— May increase phenytoin serum levels; monitoring of phenytoin levels recommended.
- Fluorouracil + Phenytoin Sodium— May increase phenytoin serum levels; monitoring of phenytoin levels recommended.
- Fluorouracil + Tinidazole— Tinidazole may decrease the clearance of fluorouracil. Monitor for fluorouracil-associated toxicities.