Hyponatremia during carbamazepine therapy in patients with intellectual disability

Carbamazepine is an anticonvulsant and psychotropic medication commonly use d in the treatment of people with intellectual disability (ID). The inciden ce of hyponatremia during treatment in this population is unclear. The pres ent study aimed to determine the prevalence of hyponatremia during carbamaz epine treatment in patients with ID, and to investigate the risk factors an d clinical features of this condition. The prevalence of hyponatremia was r etrospectively assessed in 53 people receiving carbamazepine (subject group ) and 64 people not receiving carbamazepine (control group) who lived in a residential centre for people with ID. The relationship between serum sodiu m level, sex, age, daily carbamazepine dose and serum carbamazepine levels was examined. The prevalence of the clinical features of hyponatremia was a ssessed in this population using a checklist. The prevalence of hyponatremi a was 41 5% and 9.4% in the subject and control groups, respectively. The m ean serum sodium level in the subject group was significantly lower than th at in the control group. Hyponatremia correlates significantly with a high daily carbamazepine dose and a high serum carbamazepine level. The checklis t of clinical features was not useful in detecting hyponatremia clinically. Hyponatremia is a common occurrence in this population. In the light of th e uncertain significance of mild, chronic hyponatremia, the value of routin e monitoring of serum electrolytes has yet to be established.