A fatal outcome after unintentional overdosing of rivastigmine patches.
BACKGROUND
Rivastigmine is an acetylcholine esterase inhibitor used in the treatment of dementia. Patches with rivastigmine for transdermal delivery have been used to increase compliance and to reduce side effects.


METHODS
We describe an 87-year old male with dementia treated with multiple rivastigmine patches (Exelon 9,5 mg/24 h) who developed nausea, vomiting and renal failure with disturbed electrolytes resulting in death. The symptoms occurred after six rivastigmine patches had concomitantly been erroneously applied by health care personnel on two consecutive days. The terminal cause of death was considered to be uremia from an acute tubular necrosis that was assessed as a result of dehydration through vomiting. The rivastigmine intoxication was assessed as having caused or contributed to the dehydrated condition. The medication error occurred at least partly due to ambiguous labeling. The clinical signs were not initially recognized as adverse effects of rivastigmine.


CONCLUSIONS
The presented case is a description of a rivastigmine overdose due to a medication error involving patches. This case indicates the importance of clear and unambiguous instructions to avoid administration errors with patches and to be vigilant to adverse drug reactions for early detection and correction of drug administration errors. In particular, instructions clearly indicating that only one patch should be applied at a time are important.
Department of Drug Research/Clinical Pharmacology, Faculty of Health Sciences, Linköping University, Department of Clinical Pharmacology, County Council of Östergötland, S-581 85 Linköping, Sweden. Henrik.Lovborg@lio.se
Henrik
H
Lövborg
Anna K
AK
Jönsson
Staffan
S
Hägg
D000369:Aged, 80 and over; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage / Q000506:poisoning* / Q000627:therapeutic use; D003704:Dementia / Q000188:drug therapy*; D004348:Drug Labeling / Q000592:standards; D062787:Drug Overdose; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D008508:Medication Errors; D048448:Phenylcarbamates / Q000008:administration & dosage / Q000506:poisoning* / Q000627:therapeutic use; D000068836:Rivastigmine; D057968:Transdermal Patch
D002800:Cholinesterase Inhibitors; D048448:Phenylcarbamates; D000068836:Rivastigmine