Article date: November 2010
Memantine (Ebixa) is indicated for the treatment of patients with moderate to severe Alzheimer’s disease, and tablets and an oral solution have been available since 2002. A pump device was introduced in March 2010 and replaces memantine oral solution administered by a dropper, which is being phased out by February 2011.
Risk of medication errors and accidental overdose
Up to 9 August 2010, 7 cases of administration errors with the pump device have been reported worldwide. One patient was admitted to hospital and recovered, and 2 patients experienced somnolence, which is listed in the summary of product characteristics as a possible adverse reaction associated with overdose. The remaining patients did not report any side effects.
The medication errors resulted from confusion between doses delivered by the new pump device and doses delivered by the dropper. Dosing for memantine devices is as follows:
- 1 actuation of the pump device delivers 0.5 mL of solution, corresponding to 5 mg memantine. The maximum daily dose is 20 mg (ie, four pump actuations)
old dropper device (being phased out):
- the dropper device delivers 0.5 mg/drop and the maximum daily dose of 20 mg is achieved with 40 drops
Healthcare professionals should be aware of the correct use and administration of memantine pump device as outlined in the summary of product characteristics. Healthcare professionals should also advise patients and their carers to carefully read the patient information leaflet for memantine oral solution delivered by a pump device.
Advice for healthcare professionals:
- there are differences in dose delivery between the pump device and dropper device for memantine
- 1 actuation of the pump device delivers 0.5 mL of solution, corresponding to 5 mg memantine. The maximum daily dose is 20 mg or four pump actuations, whereas 40 drops could be given with the dropper
- please be vigilant regarding dose delivery for memantine products, particularly during the transition period from the dropper device to the new pump device. We request that you also advise patients and their caregivers:
- how to use the new pump device to deliver the prescribed dose
- to carefully read the patient information leaflet for memantine oral solution delivered by a pump device
A letter has been sent to healthcare professionals in October 2010 with information on this risk. Further information for patients can be found in the memantine patient information leaflet.
Report suspected adverse reactions
Please report any suspected adverse reactions associated with the use of memantine on a Yellow Card (www.yellowcard.gov.uk). Patients and caregivers can also report any suspected reactions to us via the Yellow Card Scheme.
Article citation: Drug Safety Update Nov 2010 vol 4, issue 4: A2.