Inadvertent oral administration of methylergometrine maleate to children in the first months of life: from surveillance to prevention.

Abstract

Methylergometrine maleate is an ergot alkaloid frequently used in obstetrics for prevention and treatment of post partum haemorrhage. Accidental administration of this medicine to newborns can cause severe effects and should be carefully prevented. The present paper is aimed at describing the main characteristics of cases accidentally exposed to this medicine in Italy before and after Novartis, the manufacturer of Methergin®, a widely used methylergometrine maleate-containing gynecological medication, decided to withdraw the drop preparation from the European market. The study design is a case-series study. The database of the National Poison Control Centre of Milan was searched retrospectively (from 1 January 2005 to 31 December 2011) and prospectively (from 1 January 2012 to 31 December 2013) in order to provide a descriptive analysis of the main characteristics of cases unintentionally exposed to methylergometrine maleate and to document the impact of Novartis' decision. In the first period under study (2005-2011), a total of 642 cases of exposure to methylergometrine maleate were identified. Most of them were children aged <1 year (No. 483, 75%). Patients aged 1-2 and 3-5 years accounted for 13% (No. 85) and 9% (No. 56) of cases, respectively. Among children aged <1 year, about 76% (No. 368) were exposed during the first month of life, including 44% (No. 211) of cases exposed in the first week of life. The main cause of exposure was medication error (No. 432, 89%), mainly due to oral administration of methyltergometrine maleate in place of a paediatric preparation (No. 469, 97%). About 14% of these cases suffered clinical effects as a consequence of the exposure. Severity of poisoning was minor in 45 cases, moderate in 12, and severe in one case. The main cause of exposure among children aged 1-2 and 3-5 years was uncontrolled access to the medicine, accounting for 78% (No. 66) and 77% (No. 43) of cases, respectively. Some 9% (No. 8) of cases aged 1-2 years and 7% (No. 4) of those aged 3-5 years developed signs/symptoms possibly related to the exposure. For all of them, severity of clinical effects was low, but one case suffered moderate effects. Exposure to the medicine in drops was reported for 87% (No. 74) and 84% (No. 47) of cases aged 1-2 and 3-5 years, respectively. In 2012-2013 a total of 25 cases were observed. Among them, two patients were aged <1 year (8%). Both cases occurred in 2012 and were inadvertently administered the medicine in drops still available (present) in the home. Fourteen (56%) and 8 (32%) cases were aged 1-2 and 3-5 years, respectively. All of them were exposed to the tablet formulation following uncontrolled access to the medicine. The observations here reported indicate that having different formulations for methylergometrine maleate-containing products intended for the mother and paediatric medicines can successfully prevent medication error due to medicine exchange in the first months of life.