<p>This IV is not physically compatible with alkaline solutions or moderately alkaline drugs such as Acetazolamide, Chlorothiazide sodium, Aminophylline, sodium bicarbonate, Tetracycline HCl. It has also been reported that folic acid is unstable in the presence of calcium salts such as calcium gluconate. Direct addition of This IV to intravenous fat emulsions is not recommended. Thiamine, riboflavin, pyridoxine, niacinamide, and ascorbic acid have been reported to decrease the antibiotic activity of erythromycin, doxycycline and lincomycin. Folic acid may lower the serum concentration of phenytoin resulting in increased seizure frequency. Folic acid may decrease the patient&#39;s response to methotrexate therapy.</p>