精神分裂病に下垂体性巨人症を合併した1症例 : プロモクリプチン併用についての考察

Abstract

Bromocriptine is an ergot alkaloid derivative that possesses both dopamine agonist and antagonist activity. This biphasic action has allowed bromocriptine to be used for many psychiatric disorders. We describe a rare case of schizophrenia with pituitary gigantism, whose psychiatric symptoms were improved by concomitant bromocriptine therapy with neuroleptics. The patient (a 30-year-old single female) had been suffering from schizophrenia during the past 12 years. In remission, she was employed in accounting. At age 25, brain CT scanning revealed a pituitary tumor, but operation was not indicated. At age 30, she discontinued neuroleptics by herself. As a result, she had a relapse and entered a psychiatric hospital for the first time. Her psychiatric symptoms were auditory hallucination, delusion of persecution, reference and control, and depersonalization. Neurological symptoms were not present. Serum growth hormone ranged from 4 to 13.6 ng/ml (normal 0.6-3.7 ng/ml). Brain MRI scanning also revealed a pituitary tumor, of a size less than 1 centimeter and localized in sella turcica. Bromperidol improved her symptoms for the most part, but depersonalization continued obstinately. After a while, she was started on bromocriptine 2.5mg daily together and increased gradually. At 7.5mg daily her depersonalization began to be reduced and then at 15 mg daily it disappeared. Through the course of treatment, there were no side effects of bromocriptine therapy. Generally at low doses bromocriptine acts on the presynaptic autoreceptor as antagonist activity, while at higher doses, bromocriptine works directly on the postsynaptic receptor as agonist activity. However in this case the effective dose was a moderate dose, 15 mg daily ; finally bromocriptine may act as antipsychotic action. Concomitant bromocriptine therapy with neuroleptics were useful in schizophrenia with pituitary gigantism.