FDA label 3f82517c-5353-4eb1-8e91-63dd108f3532

WARNINGS Caution is recommended in patients with a history of bipolar illness.

INTERACTIONS Drugs which may interact with folate include: First generation anticonvulsants: High dose folic acid may result in decreased serum levels for first generation anticonvulsants (carbamazepine, fosphenytoin, phenytoin, phenobarbital, primidone, valproic acid, valproate). This may possibly reduce the effectiveness of first generation anticonvulsants and/or increase the frequency of seizures in susceptible patients. Nevertheless, caution should be used when prescribing folates among patients who are receiving treatment with first generation anticonvulsants. Second-generation anticonvulsants: Information on second-generation anticonvulsants' (including, but not limited to, lamotrigine) effect on folate levels is limited and cannot be ruled out. Capecitabine: Folinic acid (5-formyltetrahydrofolate) may increase the toxicity of Capecitabine. Cholestyramine: Reduces folic acid absorption and reduces serum folate levels. Colestipol: Reduces folic acid absorption and reduces serum folate levels. Colchicine: Colchicine may decrease folate plasma levels. L-dopa: L-dopa may decrease folate plasma levels. Cycloserine: Reduces folic acid absorption and reduces serum folate levels. Dihydrofolate Reductase Inhibitors (DHFRI): DHFRIs block the conversion of folic acid to its active forms, and lower plasma and red blood cell folate levels. DHFRIs include aminopterin, methotrexate, pyrimethamine, triamterene, and trimethoprim. Caution should be exercised when using folate with folate antagonists. Patients, typically, should not be given folate simultaneously with a folate antagonist, for the purpose of reducing or preventing clinical toxicity, as the therapeutic effect of the antagonist may be nullified. Fluoxetine: Fluoxetine exerts a noncompetitive inhibition of the 5-methyltetrahydrofolate active transport in the intestine. Isotretinoin: Reduced folate levels have occurred in some patients taking isotretinoin. Nonsteroidal Anti-inflammatory Drugs (NSAIDs): NSAIDs have been shown to inhibit some folate dependent enzymes in laboratory experiments. NSAIDs include ibuprofen, naproxen, indomethacin and sulindac. Oral Contraceptives: Serum folate levels may be depressed by oral contraceptive therapy. Methylprednisolone: Reduced serum folate levels have been noted after treatment with methylprednisolone. Pancreatic Enzymes, including, but not limited to pancreatin and pancrelipase: Reduced folate levels have occurred in some patients taking pancreatic extracts. Pentamidine: Reduced folate levels have been seen with prolonged intravenous pentamidine. Smoking and Alcohol: Reduced serum folate levels have been noted. Sulfasalazine: Inhibits the absorption and metabolism of folic acid. Metformin treatment in patients with type 2 diabetes decreases serum folate. Warfarin can produce significant impairment in folate status after a 6-month therapy. Folate may enhance the toxicity of fluorouracil. Concurrent administration of chloramphenicol and folate in folate-deficient patients may result in antagonism of the haematopoietic response to folate. Caution should be exercised with the concomitant use of folate and trimethoprim-sulfamethoxazole for the acute treatment of Pneumocystis carinii pneumonia in patients with HIV infection as it is associated with increased rates of treatment failure and mortality in a placebo controlled study. Drugs which may interact with pyridoxine hydrochloride: Pyridoxine hydrochloride should not be given to patients receiving the drug levodopa, because the action of levodopa is antagonized by pyridoxine hydrochloride. However, pyridoxine hydrochloride may be used concurrently in patients receiving a preparation containing both carbidopa and levodopa.

ADVERSE REACTIONS Allergic sensitization has been reported following both oral and parenteral administration of folic acid, as well as possibly the use of other forms of folates – including reduced folates. Paresthesia, somnolence, nausea and headaches have been reported with pyridoxine hydrochloride. Mild transient diarrhea, polycythemia vera, itching, transitory exanthema and the feeling of swelling of the entire body have been associated with cyanocobalamin.