title: Clinical studies of thiazide-induced hyponatremia.
abstract: To determine the prevalence and vulnerability of symptoms from thiazide-induced hyponatremia, we reviewed 223 cases of symptomatic hyponatremia enrolled between January 1996 and April 2002. There was a high frequency of neurologic manifestation of thiazide-induced hyponatremia, whereas clinical dehydration was not a discernible feature. Female patients presented with lower serum sodium levels than male counterparts (114+/-8 versus 117+/-8 mmol/L, P=0.02), although the frequency of central nervous system manifestation was comparable between two gender groups. The most frequent symptoms were malaise and lethargy (49%), followed by dizzy spells (47%) and vomiting (35%). Degree of hyponatremia upon presentation predicted the development of confusion and vomiting symptoms. Serum sodium concentration < or =115 mmol/L was significantly associated with the development of confusion (odds ratio 2.6, 95% confidence interval 1.3 to 5.1, P=0.004). Our results show that symptoms from thiazide-induced hyponatremia primarily reflect osmotic water shift into brain cells rather than extracellular fluid volume depletion.
authors.affiliation: Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China. Chow_Kai_Ming@alumni.cuhk.net
authors.forename: Kai Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Bonnie Ching-Ha
authors.initials: BC
authors.lastname: Kwan
authors.forename: Cheuk Chun
authors.initials: CC
authors.lastname: Szeto
mesh_terms: D000368:Aged; D001581:Benzothiadiazines; D003221:Confusion; D003937:Diagnosis, Differential; D004232:Diuretics; D005260:Female; D006760:Hospitalization; D006801:Humans; D007010:Hyponatremia / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012964:Sodium / Q000097:blood; D049993:Sodium Chloride Symporter Inhibitors / Q000009:adverse effects*; D014839:Vomiting
chemical_list: D001581:Benzothiadiazines; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D012964:Sodium