Adverse drug reactions in patients older than 70 years during the heat wave occurred in France in summer 2003: a study from the French PharmacoVigilance Database

Objective To evaluate adverse drug reactions (ADRs) inpatients older than 70 years reported during the 2003 summer heat wave in France to the French Network of Pharmacovigilance Centres and to discuss the interest of such a pharmacovigilance database in the surveillance of such sanitary alerts. Methods All 'serious' ADRs occurred in patients older than 70 years between 1st July and 31st August 2003, reported to the French network of Pharmacovigilance Centres and recorded in the French PharmacoVigilance Database, were analysed with respect to age, gender, type of ADR, drug(s) involved as well as imputability of heat wave. Results The total number of 'serious' ADRs registered in the French PharmacoVigilance Database inpatients older than 70 years was similar in 2003 (a year with heat wave) and in 2002 (a year without heat wave). Sixty-eight ADRs [27 'possible' (11) 27 'plausible' (12) and 14 'likely' (13)] related to heat occurred in 2003, with a maximal peak between the 28th July and the 17th August. The most frequently ADRs were metabolic (dehydratation, hydroelectrolytic disturbances) and neuropsychiatric (confusion, falls, coma). Drugs more frequently involved were diuretics, angiotensin converting enzyme inhibitors, antidepressants (mainly serotonin reuptake inhibitors), proton pump inhibitors, digoxin, benzodiazepines, oral hypoglycemics and sartans. Conclusion This study underlines the role of heat wave in the occurrence of 'serious' ADRs in elderly. However, the French PharmacoVigilance Database was not enough sensitive to be used as an efficient surveillance system (luring such an acute episode, like a heat wave (at least while underreporting remains so important). Copyright (c) 2006 John Wiley & Sons, Ltd.