Phenelzine treatment of panic disorder: lack of effect on pyridoxal phosphate levels.

Earlier reports indicated that phenelzine treatment may result in clinically significant reductions of vitamin B6 in some individuals. Sixteen subjects, ages 21-59 years (seven men, nine women) with panic disorder with or without agoraphobia were treated with an average of phenelzine 53.5 mg/day for an average of 10 weeks in an open treatment study. No significant effects on plasma levels of pyridoxal phosphate, the active form of vitamin B6, were discernible in this group, nor was there any clear relationship between pyridoxal phosphate levels and symptoms in the subgroup of five patients who did develop deficiency-type symptoms. Pyridoxine replacement had unclear effects in symptomatic patients.