In addition to switching to an antipsychotic with looser D2 binding, other medications for treating polydipsia have been studied. It is hypothesized that the alpha-2 adrenergic system may play a role in thirst regulation. For example, mianserin, an alpha-2 antagonist, may decrease water intake. However, studies have been small and inconsistent.8,9 Propranolol,10 a beta adrenergic receptor blocker; irbesartan,11 an angiotensin-II receptor blocker; demeclocycline,12 a tetracycline that inhibits antidiuretic hormone action; and naltrexone,9 a mu opioid antagonist, have been studied with inconclusive results and a variety of adverse effects5,7,13 (Table 28-13).
Behavioral interventions for patients with psychogenic polydipsia include fluid restriction, twice-daily weight checks, cognitive-behavioral therapy, and reinforcement schedules, which may be useful but less realistic due to need for increased supervision.11,12 Patient and family education on the signs of hyponatremia are important to prevent serious complications, such as those Mr. F experienced.
OUTCOME Repeated hospitalizations
Mr. F is discharged with follow-up in our psychiatry clinic and attends 1 appointment. At that time, his mother reports that Mr. F is compliant with his medication and has limited fluid intake. However, over the next 2 months, he is admitted to our psychiatric unit twice with similar presentations. Each time, the treatment team has extensive discussions with Mr. F’s mother about strategies to limit his water intake and the possibility of residential placement due to his need for a higher level of care. Although she acknowledges that nursing home placement may be needed in the future, she is not ready to take this step.
Three months later, Mr. F returns to our hospital with severe abdominal pain and is found to have a perforated bowel obstruction. His sodium is within normal limits on presentation, and the psychiatry team is not involved during this hospitalization. Mr. F is treated for sepsis and undergoes 3 exploratory laparotomies with continued decline in his health. He dies during this hospitalization. The cause of Mr. F’s perforated bowel obstruction is not determined, and his family does not pursue an autopsy.
The authors’ observations
At Mr. F’s final hospital presentation, his sodium was normal. It is possible Mr. F and his mother had found an acceptable fluid restriction routine, and he may have been doing better from a psychiatric perspective, but this will remain unknown.
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