Risperidone Addition and Psychotic Exacerbation

The patient is a 52-year-old single man with a university education. He was seen at the age of 26, and at that time he manifested delusions of persecution, impulsive and aggressive behavior, and excitement. For the 26 years since then, he has been hospitalized. During hospitalization, his symptoms developed into systematized delusions. He was convinced that he was born in China as a son of the Chinese president and a Japanese mother, and that he came to Japan with Japanese soldiers after the Second World War. Also, he insisted that the Chinese government implanted 2.01 cm of metallic nail into his occipital muscle as revenge when he was a baby, and that via the metallic nail, electric waves were often conveying a command, disturbing sleep and inducing irritability. Although an X-ray of his head demonstrating there was no metallic nail was shown to him, he did not correct his thoughts at all.

He had been put on several psychotropics, including haloperidol 15 mg/day and lithium 800 mg/day (serum lithium levels: 0.4–0.7 mEq/ l), for 5 years. With these medications, he did not complain of his metallic nail spontaneously, but he did so when he was asked about its existence. Because he suffered from loss of activity and spontaneity, the medications were changed. Lithium was discontinued because it did not seem to have a significant effect in this patient, and 39 days after lithium discontinuation, risperidone 2 mg/day was added to the other drugs. After risperidone was increased to 6 mg/day over 2 weeks, unexpectedly he began to complain obstinately of his metallic nail. Furthermore, he demanded to be operated on for its removal. He also showed irritability, anxiety, and severe insomnia. Thus, risperidone was discontinued after 37 days; 10 mg of haloperidol was injected for 4 days, and haloperidol 40 mg/day po was added. The intensity of his delusions was decreased within a week.

Forty-seven days after risperidone discontinuation, risperidone 2 mg/day was resumed in order to investigate whether risperidone administration or lithium discontinuation worsened his delusions. Risperidone was increased to 6 mg/ day over 2 weeks, a pace similar to that of the previous increment, with haloperidol 40 mg/day. As a result, he again began to complain of his metallic nail persistently. Immediately, risperidone was discontinued, but he again demanded to be operated on for removal of his metallic nail. He also showed irritability, anxiety, and severe insomnia. It was necessary to add levomepromazine 50 mg/day. However, as in the previous episode, the intensity of his delusions was decreased within a week after risperidone discontinuation. Throughout the following 16 months, he did not complain of his metallic nail spontaneously.

In the present case risperidone addition to conventional neuroleptics, rather than lithium discontinuation, is likely to have exacerbated the psychotic symptoms, considering that risperidone rechallenge brought about a similar exacerbation.