L-dopa: The effect of L-dopa may be reduced when vitamin B6 is administered concomitantly.
Pyridoxine-antagonists, eg, isoniazid (INH), cycloserine, penicillamine, hydralazine: The efficacy of vitamin B6 may be decreased.
Loop diuretics eg, furosemide: In long-term use, the blood level of vitamin B1 may be reduced. Avoid taking any preparations (e.g. supplements) that include vitamin B6 (pyridoxine) together with NEUROBION.