Published: 2 March 2017

MARC’s Remarks: December 2016 Meeting

Prescriber Update 38(1): 7
March 2017

The Medicines Adverse Reactions Committee (MARC) met on 1 December 2016 to discuss a number of medicine-related safety issues.

The MARC discussed ophthalmological monitoring in patients taking hydroxychloroquine. The MARC considered the available evidence and concluded that there is reasonably good support for a first ophthalmologic review within one year of starting hydroxychloroquine and, in the absence of major risk factors, a further review after five years. After five years of use, the MARC considered the frequency of monitoring is dependent on each patient’s risk factors however, yearly monitoring should be a minimum. In addition, wherever possible, optical coherence tomography (OCT) and visual field testing are recommended.

The MARC discussed some of the principles and difficulties of decision making and risk communication to healthcare professionals and consumers.

The MARC discussed a case concerning an older patient taking enoxaparin who had a history of chronic kidney disease. The patient experienced a fatal cerebral haemorrhage. The MARC noted that caution should be taken around the use of low molecular weight heparin in patients with impaired renal function. The data sheet states that dose adjustment is required for patients with severe renal impairment ( This case demonstrates the importance of clinical monitoring when using enoxaparin.

At the 167th MARC meeting held on 8 September 2016, the Committee noted that the data sheets for aciclovir-containing products have recently been updated to include ‘confusion’ as an adverse effect. Aciclovir is used at high doses in the elderly for the treatment of shingles. Healthcare professionals are reminded that use of high-dose aciclovir increases the risk of confusion, and care should be taken.

Further information on the meeting held on 1 December 2016 can be found on the Medsafe website (