Niacinamide Interactions

Drugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides (e.g., erythromycin, clarithromycin), fluoxetine, fluvoxamine, trazodone, omeprazole, oxybutynin, isoniazid, niacinamide (nicotinamide), azoles (e.g., ketaconazole, itraconazole, fluconazole, voriconazole), acetazolamide, verapamil, ticlopidine, grapefruit juice, and protease inhibitors.

Source: FDA drug label - carbamazepine

All of the assays in which interference has been reported involve enzymatic coupling of the assay to oxidation-reduction of nicotinamide adenine dinucleotide (NAD+ NADH).

Source: FDA drug label - metronidazole

The following are examples of these types of interactions: Effect of INFUVITE ADULT on other drugs: • Antibiotics: Thiamine, riboflavin, pyridoxine, niacinamide, and ascorbic acid decrease activities of erythromycin, kanamycin, streptomycin, doxycycline, and lincomycin ( 7.1 ) • Bleomycin: Ascorbic acid and riboflavin may reduce the activity of bleomycin ( 7.1 ) • Levodopa: Pyridoxine may decrease blood levels of levodopa and levodopa efficacy may decrease ( 7.1 ) • Phenytoin: Folic acid may decrease phenytoin blood levels and increase risk of seizure activity ( 7.1 ) • Methotrexate: Folic acid may decrease response to methotrexate ( 7.1 ) Effects of other drugs on INFUVITE ADULT: • Hydralazine, Isoniazid: Concomitant administration of hydralazine or isoniazid may increase pyridoxine requirements ( 7.2 ). Antibiotics : Thiamine, riboflavin, pyridoxine, niacinamide, and ascorbic acid decrease antibiotic activities of erythromycin, kanamycin, streptomycin, doxycycline, and lincomycin.

Source: FDA drug label - multiple vitamins injection