Abstract
Introduction: Confusion is an adverse drug reaction frequently observed with valproic acid. Some case reports are published in the literature but no systematic study from a sample of patients has been published. We performed this study in order to describe the main characteristics of this adverse drug reaction.
Methods: Using the French Pharmacovigilance database, we selected the cases of confusion reported since 1985 with valproic acid.
Results: 272 cases of confusion were reported with valproic acid: 153 women and 119 men. Confusion mostly occurred during the two first weeks following valproic acid exposure (39.7%). It was “serious” for almost 2/3 of the patients (62.5%) and its outcome favourable in most of the cases (82%). The occurrence of this ADR was more frequent in patients aged between 61 and 80 years.
Conclusion: This work shows that confusion with valproic acid is a serious, rather frequent but reversible adverse drug reaction. It occurs especially in older patients and during the first two weeks of treatment.
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Correspondence
E. Bondon-GuittonPharmD, PhD
Laboratoire de Pharmacologie Médicale et Clinique
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