Vol-Tab Rx Tablets

Folic acid, when prescribed as a single agent in doses above 0.1 mg daily, may obscure the detection of B₁₂ deficiency (specifically, the administration of folic acid may reverse the hematological manifestations of B₁₂ deficiency, including pernicious anemia, while not addressing the neurological manifestations). Reduced folates may be less likely than folic acid to mask vitamin B₁₂ deficiency. Folate therapy alone is inadequate for the treatment of B₁₂ deficiency.

Vol-Tab Rx is a prescription vitamin for use only under the direction and supervision of a licensed physician.

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.

Drugs which may interact with folate include:

• Antiepileptic drugs (AED): The AED class including, but not limited to, phenytoin, carbamazepine, primidone, valproic acid, phenobarbital and lamotrigine have been shown to impair folate absorption and increase the metabolism of circulating folate. Additionally, concurrent use of folic acid has been associated with enhanced phenytoin metabolism, lowering the levels of this AED in the blood and allowing breakthrough seizures to occur.
• 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.
• 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.
• Fluoxetine: Fluoxetine exerts a noncompetitive inhibition of the 5-methyltetrahydrofolate active transport in the intestine.
• Isotretinoin: Reduced folate levels have occured 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: 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.