Involvement of the alpha2-adrenergic system in polydipsia in schizophrenic patients: a pilot study

Non-antipsychotic pharmacotherapy of psychogenic polydipsia: A systematic review

OBJECTIVE

Polydipsia is defined at the intake of excessive fluid (>3 L daily). Psychogenic polydipsia (PPD) presents without an identifiable medical cause and is often seen in patients with diagnoses of schizophrenia, OCD, anxiety, alcohol use disorder, and other psychotic disorders. The purpose of this systematic review is to assess the therapeutic effect of various non-antipsychotic medications on patients with a stable psychotic illness and concurrent PPD.

METHODS

A systematic search was conducted using the following databases: PubMed, MEDLINE with Full Text, CINAHL complete, Cochrane database of systematic reviews, Cochrane methodology register, MasterFILE Premier, APA PsychArticles, APA PsychInfo, APA PsycBooks, APA PsycTests, TRIP, Nursing and Allied Health. The quality of each retained study was assessed using appropriate risk of bias tools based on study design.

RESULTS

The initial search resulted in 1422 articles from which 22 articles were included for qualitative synthesis. Study designs ranged from case reports to double blind, placebo controlled randomized trials and was interpreted uniquely based on study design. Acetazolamide was effective in improving some PPD outcomes. Fluoxetine at high doses was effective in reducing fluid intake and polydipsia. Other medications included in this review performed equivocally for reduction of numerous parameters evaluating PPD.

CONCLUSION

No one drug appeared to be the most efficacious; however, some did show promise in specific populations. Those in need of pharmacotherapeutic options for PPD may consider one of the included agents to assist with co-morbid state. Further high-quality research is needed to provide better treatment guidance for PPD.

Role of Naltrexone in Improving Compulsive Drinking in Psychogenic Polydipsia

Psychogenic polydipsia or self-induced water intoxication is a potentially lethal condition seen in many chronic psychiatric patients. This is a literature review based on therapeutic significance of Naltrexone in improving compulsive water drinking behavior in chronic psychiatrically ill patients with psychogenic polydipsia. Naltrexone is an opioid antagonist approved by FDA for alcohol dependence. Extensive literature search provides a line of evidence that suggests correlation of opioid receptor with compulsive water ingestion in animals. However, there is limited data regarding clinical utility of naltrexone in improving psychogenic polydipsia in human species. This review highlights the necessity for further research and trials to elucidate the role of naltrexone in human psychogenic drinking behavior.

Hiponatremia in the practice of a psychiatrist. Part 2: psychogenic polydipsia

Objective. The study is the second part of the literature review on hyponatremia in patients with diagnosed mental disorders. This article focuses on psychogenic polydipsia as, along with the SIADH, one of the two most common causes of hyponatremia in the mentioned group of patients.

Method: The literature review was based on searching the Medline, the Google Scholar and the Ebsco databases in Polish and English by entering the following phrases: psychogenic polydipsia, the psychosis – intermittent hyponatremia – polydipsia syndrome, water intoxication.

Discussion: Psychogenic polydipsia occurs in up to 25% of patients treated for mental disorders. It most frequently concerns patients with schizophrenia. 30% of patients with psychogenic polydipsia suffer from hyponatremia with or without symptoms of water intoxication. In the etiology of psychogenic polydipsia, the influence of dopaminergic and noradrenergic neurotransmission has been considered, as well as angiotensin, which is claimed to have dipsogenic properties. In order to reduce the severity of the disorder, attempts have been made to administer the following groups of medications: β-blockers, opioid receptor antagonists, angiotensin convertase inhibitors and angiotensin receptor antagonists. Other methods include replacing classic antipsychotic drugs with clozapine. There are also reports of a reduced severity of polydipsia with hyponatremia after introducing risperidone and olanzapine. Preventing episodes of water intoxication in patients with psychogenic polydipsia requires the monitoring of their body weight and a suitable reduction of fluid intake by them.

Results: Mentally ill patients, especially those with chronic schizophrenia, should be monitored for psychogenic polydipsia and the concomitant hyponatremia.

Antidepressants and the risk of hyponatremia: a Danish register-based population study

OBJECTIVE

To examine the association between classes of antidepressants and hyponatremia, and between specific antidepressants and hyponatremia.

DESIGN

Retrospective register-based cohort study using nationwide registers from 1998 to 2012.

SETTING

The North Denmark Region.

PARTICIPANTS

In total, 638 352 individuals were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Plasma sodium was obtained from the LABKA database. The primary outcome was hyponatremia defined as plasma sodium (p-sodium) below 135 mmol/L and secondary outcome was severe hyponatremia defined as p-sodium below 130 mmol/L. The association between use of specific antidepressants and hyponatremia was analysed using multivariable Poisson regression models.

RESULTS

An event of hyponatremia occurred in 72 509 individuals and 11.36% (n=6476) of these events happened during treatment with antidepressants. Incidence rate ratios and CIs for the association with hyponatremia in the first p-sodium measured after initiation of treatment were for citalopram 7.8 (CI 7.42 to 8.20); clomipramine 4.93 (CI 2.72 to 8.94); duloxetine 2.05 (CI 1.44 to 292); venlafaxine 2.90 (CI 2.43 to 3.46); mirtazapine 2.95 (CI 2.71 to 3.21); and mianserin 0.90 (CI 0.71 to 1.14).

CONCLUSIONS

All antidepressants except mianserin are associated with hyponatremia. The association is strongest with citalopram and lowest with duloxetine, venlafaxine and mirtazapine.

Association analysis between the C-1291G polymorphism in the promoter region of the adrenergic alpha2A receptor gene and polydipsia in schizophrenia

Several lines of studies have shown the existence of an important inhibitory mechanism for the control of water intake involving adrenergic alpha2A receptors (ADRA2A). A human study using patients with schizophrenia demonstrated an exacerbation of polydipsia by the administration of clonidine, an ADRA2A-agonist, and a relief of polydipsia by mianserin, an ADRA2A-antagonist, suggesting the involvement of the central adrenergic system in the drinking behavior of patients with schizophrenia. Based on these findings we examined a possible association between the C-1291G polymorphism in the promoter region of the ADRA2A gene and polydipsia in schizophrenia using a Japanese case-control sample. Our sample includes 348 patients with schizophrenia (DSM-IV) (84 with polydipsia and 264 without polydipsia). No significant association between the ADRA2A C-1291G polymorphism and polydipsia was found. Our result suggests that the ADRA2A C-1291G polymorphism may not confer susceptibility to polydipsia in schizophrenia in our sample. Further studies with larger samples are warranted.

Schizophrenic patients with polydipsia and water intoxication more often have a form of schizophrenia first described by Kraepelin

Polydipsia and water intoxication (PWI) seem to be associated with a particular form of schizophrenia, first described by Kraepelin, involving negative symptoms, disorganization and poor outcome. In this study, a group of 20 schizophrenic patients with PWI was selected and matched for age, duration of illness and gender with a group of 20 schizophrenic controls with no PWI. For these patients the following measure were obtained: clinical and demographic data, Keefe's criteria for Kraepelinian schizophrenia, the Positive and Negative Syndrome Scale score and the score on Fagerström's Nicotine Dependence Scale. The group of schizophrenic patients with PWI presents significantly higher levels of negative symptoms, disorganized symptoms and general symptoms of psychopathology, and it is composed of a significantly higher percentage of Kraepelinian patients. These results show an association of polydipsia and water intoxication with Kraepelinian schizophrenia suggesting physiological hypotheses for a specific pathogenic pathway.

Effects of clonidine in schizophrenic patients with primary polydipsia: three single case studies

A pilot study was conducted in schizophrenic patients with primary polydipsia to determine the tolerability of adding clonidine to an existing antipsychotic drug regimen and to seek evidence of an antidipsic effect. Three patients with chronic schizophrenia and primary polydipsia underwent open controlled prospective trials of treatment with clonidine in doses of up to 800 microg/day. The trials lasted from 2 to 5 months each, and analysis of variance was used to test for changes in dependent variables on a case-by-case basis. Blood pressure and pulse declined significantly in a dose-dependent manner, but fluid intake, as assessed by measurements of weight and 24-h urine volume, was not affected. Hypotension and bradycardia limited the extent to which the dose of clonidine could be increased. The lack of evident effect of clonidine on polydipsia in this small sample and the inconsistent results of two other recent studies of clonidine in patients with schizophrenia and primary polydipsia provide little overall support for the effectiveness of clonidine treatment in primary polydipsia associated with schizophrenia.

Association analysis of polymorphism in the promoter region of the alpha2a-adrenoceptor gene with schizophrenia and clozapine response

There exists considerable evidence implicating the alpha (alpha) adrenergic system in the superior therapeutic effects of clozapine for the treatment of schizophrenia, as also its associated adverse hypersalivation side effect. It would seem plausible for variants of the adrenoceptors to be associated with the clozapine response. The present study tested the hypothesis that a biallelic polymorphism in the promoter region of the alpha2a-adrenoceptor gene confers susceptibility to schizophrenia, and is associated with a clozapine-induced (favorable) therapeutic response and/or a clozapine-induced hypersalivation. Ninety-seven treatment-resistant schizophrenic patients were assessed using the Brief Psychiatric Rating Scale before and after clozapine treatment. The results of clozapine treatment demonstrated that the alpha2a-adrenoceptor gene variants did not play a major role in the susceptibility, hypersalivation adverse effect or clozapine response of patients with schizophrenia. The polymorphism of the alpha2a-adrenoceptor gene investigated is not likely to play a major role in the pathogenesis of schizophrenic disorders or clozapine response, although the hypothesis that these genes are implicated in the cognitive deficit and polydipsia associated with schizophrenic disorders may, however, still warrant further study.

Is propranolol effective in primary polydipsia?

OBJECTIVE

Psychiatric patients presenting with polydipsia are often difficult to treat with standard psychiatric interventions. Pharmacological intervention was attempted in these patients based on the hypothesis that angiotensin II, a potent dipsinogen, may be involved in the drinking behavior of patients with polydipsia. Beta-blockers inhibit renin release (and thus indirectly angiotensin II) by blocking beta receptors in the kidney.

METHODS

Three patients were identified as excessive water drinkers during their hospital admissions. All three patients were eunatremic but polydipsic at the time of study. Two of the three had histories of hyponatremia and required emergency medical treatment on more than one occasion. No patients had been controlled by strict fluid restriction. Trials of propranolol were initiated to control their water drinking.

RESULTS

After starting propranolol, two patients responded quickly. In one patient, fluid intake decreased from 2650 +/- 647 to 1577 +/- 361, p < .001. In the other, fluid intake decreased from over 7000 ml before starting propranolol to around 3000 ml. The mean noon body weight of the third patient, in whom it was not possible to document fluid intake or urine volume before and after administering beta-blocker, was 72.6 +/- 2.6 Kg and 66.0 +/- 1.0 Kg, respectively (p < .0001).

CONCLUSIONS

These results suggest that propranolol may be useful for the treatment of polydipsia in patients with schizophrenia. Its efficacy could be related to inhibition of the renin-angiotensin system. Additional research using the controlled pharmacotherapeutic trials is required to confirm these findings.