Published: 10 December 2015
Publications
Monitor Renal Function in Elderly Patients Taking Dabigatran
Prescriber Update 36(4): 55
December 2015
The Centre for Adverse Reactions Monitoring (CARM) continues to receive
reports of bleeding in elderly patients taking dabigatran.
Age-related decline of renal function is expected in older patients (>75 years of age) 1. Renal insufficiency causes an increase in plasma concentration of dabigatran which increases the risk of bleeding2.
Renal function must be monitored in elderly patients taking dabigatran. Monitoring should start prior to treatment and at least once yearly thereafter. If the patient is at risk of worsening renal impairment more frequent monitoring is recommended3.
Patients with impaired renal function and those over 80 years of age should take the reduced daily dose of 220 mg (110 mg twice daily). Dabigatran is contraindicated in patients with severe renal impairment (CrCl <30 mL/min)1.
Bleeding is a well-recognised side effect seen with all anticoagulants. All patients should be monitored for signs of bleeding. The main risk factors for dabigatran associated bleeding are age of 75 years old and greater, renal impairment (30-50 mL/min CrCl) and use with other medicines that can cause bleeding such as aspirin or SSRIs.
CARM Cases
CARM have received a total of 720 reports where dabigatran was the medicine suspected of causing an adverse reaction. Of these, 75 reports described bleeds associated with dabigatran use (at a daily dose of 300 mg). Twenty six (35%) of these 75 reports were in patients aged 75 years and over. In nine of the 75 cases (12%) pre-existing renal disease was reported.
Further information on bleeding and the use of dabigatran can also be found in the Prescriber Update articles 'Dabigatran - is there a bleeding problem?' and 'Acute kidney injury - dangerous to continue some medicines'3,4.
References
- Boehringer Ingelheim Limited. 2015. Pradaxa Capsule Data Sheet 7 May 2015. URL: www.medsafe.govt.nz/profs/datasheet/p/Pradaxacap.pdf (accessed 2 October 2015).
- MHRA. 2011. Dabigatran (Pradaxa): risk of serious haemorrhage - need for renal function testing. Drug Safety Update December 2011. URL: http://webarchive.nationalarchives.gov.uk/20141205150130/http://www.mhra.gov.uk/Safetyinformation/DrugSafetyUpdate/CON137771 (accessed 2 October 2015).
- Medsafe. 2011. Dabigatran - is there a bleeding problem? Prescriber Update 32(3): 19-20. URL:www.medsafe.govt.nz/profs/PUArticles/DabigatranSept2011.htm (accessed 2 October 2015).
- Medsafe. 2014. Acute Kidney Injury - Dangerous to Continue Some Medicines. Prescriber Update 35(1):9-10. URL:www.medsafe.govt.nz/profs/PUArticles/March2014AcuteKidneyInjury.htm (accessed 2 November 2015).