Ineffectiveness of pyridoxine in evalution and treatment of the hyperprolactinemic amenorrhea-galactorrhea syndrome

Abstract

Pyridoxine hydrochloride (vitamin B6) has been proposed as a diagnostic and therapeutic agent for patients with amenorrhea and galactorrhea associated with elevated serum prolactin levels. Therefore five normal premenopausal women and nine consecutive patients with amenorrhea, but with no other evidence of pituitary tumor, were given 200 to 300 mg of pyridoxine IV. Mean serum prolactin and growth hormone concentrations did not change significantly from baseline following the infusion in either group. Eight of the nine amenorrhea patients had elevated serum prolactin levels and were treated with oral PDX for 91.0 ± 10.1 (S.E.) days, including 42.0 ± 8.2 days at a maximum dosage of 600 mg. per day in divided doses. Mean serum prolactin concentrations of the eight patients at completion of therapy (82.6 ± 19.1 ng. per milliliter) did not differ significantly from the pretreatment value (69.1 ± 18.4 ng. per milliliter). No subject acquired normal prolactin levels, and in two patients the serum prolactin levels increased during treatment. Galactorrhea diminished very slightly in three of the seven lactating patients but was unchanged in the remainder. Amenorrhea persisted throughout pyridoxine treatment in all eight patients. While receiving 600 mg. per day, three patients complained of headaches, lethargy, and lightheadedness which subsequently resolved when the PDX was discontinued. Thus, pryidoxine does not appear to be a useful agent for evaluation or treatment of the galactorrhea-amenorrhea syndrome.