title: Pregabalin-associated myoclonic encephalopathy without evidence of drug accumulation in a patient with acute renal failure.
abstract: Pregabalin, used for treating partial epilepsy and neuropathic pain, is usually well tolerated. Patients with impaired renal function are at risk to develop more serious adverse events. A 64-year-old woman was admitted in the Emergency Department for altered consciousness and abnormal movements. She recently started to take pregabalin (150 mg/day) for neuropathic pain. The drug was withdrawn 36 h before hospitalization following worsening of neurological symptoms. At physical examination, myoclonus was noted as main finding in the limbs and head, with encephalopathy. Laboratory investigations revealed acute renal failure with serum creatinine at 451.3 μmol/l. Urine output was preserved. After supportive care alone, myoclonus resolved after 24 h and consciousness was normal after 48 h. Renal function was also recovered. At the time of admission, the concentration of plasma pregabalin was 3.42 μg/ml, within therapeutic range. The calculated terminal elimination half-life was 11.5 h. Pregabalin-induced myoclonus may not be strictly related to drug accumulation in acute renal failure, with the possibility of a threshold phenomenon.
authors.affiliation: Department of Intensive Care Medicine, Cliniques St-Luc, Université catholique de Louvain, Brussels, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Courtois
authors.affiliation: Department of Laboratory Medicine, Laboratory of Toxicology, AZ Sint-Jan AV Hospital, Brugge, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Borrey
authors.affiliation: Louvain Centre for Toxicology and Applied Pharmacology, Université catholique de Louvain, Brussels, Belgium.
authors.forename: V
authors.initials: V
authors.lastname: Haufroid
authors.affiliation: Louvain Centre for Toxicology and Applied Pharmacology, Université catholique de Louvain, Brussels, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Hantson
keywords: Encephalopathy; myoclonus; pharmacokinetics; pregabalin