Original article Psychotropic drugs use and risk of heat-related hospitalisation Karin Martin-Latry a,b,c, * , Marie-Pierre Goumy d , Philippe Latry e , Claude Gabinski d , Bernard Be ´gaud a,b,c , Isabelle Faure d , He ´le `ne Verdoux a,c a Universite ´ Victor Segalen Bordeaux 2, France b De ´partement de Pharmacologie, CHU Bordeaux, France c Inserm U657, Bordeaux, France d Service des urgences-re ´animation, Centre Hospitalo-Universitaire de Saint-Andre ´, Bordeaux, France e Direction Re ´gionale du Service Me ´dical de l’Assurance Maladie d’Aquitaine, CNAM-TS, France Received 6 February 2007; received in revised form 23 March 2007; accepted 23 March 2007 Available online 21 May 2007 Abstract Objective. e To assess if use of psychotropic drugs is associated with an increased risk of admission for heat-related pathologies during a heat wave period. Method. e We conducted a matched caseecontrol study. Cases were defined as subjects admitted to an emergency department for heat- related pathology (hyperthermia or heat stroke) over the August 2003 heat wave. Controls were defined as subjects living in the same area but not hospitalised over the same period and who had at least one prescription form submitted for refunding by the social security insurance in July 2003. Multivariate analyses were used to identify psychotropic drugs independently associated with hospital referral during the heat wave period. Results. e Out of the 1405 patients admitted to the emergency department, 56 (4%) presented with heat-related pathology. The mean age of cases was 83 years. Multivariate analyses showed that cases were more likely than controls to be treated with anticholinergic drugs (OR 6.0, 95% CI 1.8e19.6), antipsychotics (OR 4.6, 95% CI 1.9e11.2) or anxiolytics (OR 2.4, 95% CI 1.3e4.4). Conclusion. e In special risk situations such as heat waves, the risk/benefit ratio of psychotropic drugs which could interfere with body temperature regulation has to be carefully assessed, particularly in the elderly. Ó 2007 Elsevier Masson SAS. All rights reserved. Keywords: Heat wave; Psychotropic medication; Old age 1. Introduction Over the last decades, several heat waves have occurred all over the world [16,17,20,22]. In August 2003, most European countries were confronted with an unprecedented heat wave [6,12]. The death rate increase was especially marked in France [15,26], resulting in nearly 15,000 excess deaths [7,25]. Heat waves may have a direct impact on health by inducing a failure in thermoregulation mechanisms [4]. A heat exhaustionedehy- dration syndrome occurs when high ambient temperature exceeds thermolysis capacity. Heat stroke, the most severe complication of exposure to high ambient temperature, is char- acterised by a core body temperature above 40  C associated with central nervous system symptoms (delirium, convulsion, coma). This state can lead to a multiorgan dysfunction, partly due to the cytotoxic effects of heat and the associated inflam- matory response, with acute renal, respiratory or circulatory failures, and haemorrhagic complications. The mortality rate of heat stroke is around 50% [4]. Risk factors for hospital admission related to health conse- quences of heat wave most frequently reported in the literature * Corresponding author. Inserm U657, De ´partement de Pharmacologie, Uni- versite ´ Victor Segalen, 146 rue Le ´o Saignat, 33 076 Bordeaux cedex, France. Tel: þ33 557 571 561; fax: þ33 557 574 660. E-mail address: karin.latry@pharmaco.u-bordeaux2.fr (K. Martin-Latry). 0924-9338/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.eurpsy.2007.03.007 European Psychiatry 22 (2007) 335e338 http://france.elsevier.com/direct/EURPSY/