Published: December 2012

MARC's Remarks: September 2012 Meeting

Prescriber Update 33(4): 38
December 2012

The latest meeting of the Medicines Adverse Reactions Committee (MARC) took place on 13 September 2012.

The MARC undertook a comprehensive review of antidepressants and the risk of QT prolongation. The MARC considered that the available data supported an association between many of the antidepressants reviewed and the development of QT prolongation. The MARC recommended a number of updates to the relevant data sheets. Further information on antidepressants and QT prolongation can be found in this edition of Prescriber Update1.

The MARC undertook a review of a possible association between serotonin syndrome and fentanyl, ondansetron or donepezil when taken in combination with a serotonergic agent. The MARC agreed that the published literature supports an association between fentanyl and serotonin syndrome and recommended that this information be added to the data sheet.

The MARC agreed that there is insufficient evidence at present to support an association between ondansetron and serotonin syndrome. As the use of ondansetron is increasing, the MARC recommended that further information be sought by placing ondansetron and the risk of serotonin syndrome on Medsafe's monitoring scheme M² logo.

The MARC agreed that there is insufficient evidence at present to support an association between donepezil and serotonin syndrome. However, the MARC considered that there was sufficient evidence for an increased risk of neuroleptic malignant syndrome in patients treated with donepezil and recommended data sheet updates. An article on the differential diagnosis of serotonin syndrome and neuroleptic malignant syndrome has been included in this edition of Prescriber Update2.

The MARC considered the outcome of the recent M² logo review of pantoprazole/lansoprazole and the risk of hypomagnesaemia. The MARC considered that there was enough evidence for an association between pantoprazole, lansoprazole and hypomagnesaemia and that the data sheets be updated. Additional information regarding this issue can be found in this edition of Prescriber Update3.

The MARC also reviewed a report from the Intensive Medicines Monitoring Programme (IMMP) regarding varenicline (Champix). This report included a final analysis of the data collected since varenicline monitoring was started in 2007. The MARC identified a number of issues that needed to be addressed before a robust assessment of the safety profile of varenicline in New Zealand could be made. The MARC recommended that the updated report be provided to Medsafe.

Further information regarding these issues is available from the MARC meeting minutes published on the Medsafe website

  1. Medsafe. 2012. Do all antidepressants cause QT prolongation? Prescriber Update 33(4): 33-35.
  2. Medsafe. 2012. Neuroleptic Malignant Syndrome versus Serotonin Syndrome. Prescriber Update 33(4): 31-32.
  3. Medsafe. 2012. Hypomagnesaemia — a Risk Associated with All Proton Pump Inhibitors. Prescriber Update 33(4): 32.