See also How To Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug are: chloramphenicol, methyldopa, other vitamin/nutritional supplements.
This product can decrease the absorption of other drugs such as bisphosphonates (for example, alendronate), levodopa, penicillamine, quinolone antibiotics (for example, ciprofloxacin, levofloxacin), thyroid medications (for example, levothyroxine), and tetracycline antibiotics (for example, doxycycline, minocycline). Therefore, separate your doses of these medications as far as possible from your doses of this product. Ask your doctor or pharmacist about how long you should wait between doses and for help finding a dosing schedule that will work with all your medications.
If your brand of multivitamin also contains folic acid, be sure to tell your doctor or pharmacist if you take certain anti-seizure drugs (e.g., hydantoins such as phenytoin).
This medication may interfere with certain lab tests, possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.