Volume 187 - Issue 6
Management of warfarin in atrial fibrillation
Author: Beata V Bajorek
Med J Aust 2007; 187 (6): 371. || doi: 10.5694/j.1326-5377.2007.tb01289.x
Published online: 17 September 2007
Published online: 17 September 2007
In reply: I thank Ford and Close for highlighting additional points regarding the optimal management of anticoagulants in general practice. Indeed, neither of these points was raised by our study participants.
Regarding the timing of doses, for medication safety reasons, in many hospitals the warfarin dose is listed for mid-evening administration; the recently introduced National Inpatient Medication Chart (NIMC), which incorporates a designated “warfarin section”, nominates 16:00 as the time. In the hospital setting, this timing is necessary to enable the treating medical team (rather than after-hours staff) to review the day’s blood test results, and subsequently prescribe the appropriate dose. The process ensures that treatment is optimally managed by those most knowledgeable about the patient’s regimen, prevents dose omissions, and reduces the time to dose stabilisation (and potentially, time to discharge). Ford and Close appropriately point out that this timing may not always be convenient for patients once they are discharged to the community setting. The optimal regimen should facilitate the patient’s adherence to treatment, and therefore should coordinate with the rational use of existing support services. This needs to be more carefully considered in discharge planning when warfarin therapy is involved.
Point-of-care testing is an efficient mode of monitoring anticoagulation therapy, but we were unable to expand on this in our previous discussion (due to word limits). Internationally, point-of-care testing underpins many comprehensive monitoring services, whereby allied health professionals (eg, trained nurses or pharmacists) perform the blood tests, monitor results, adjust doses, and/or prescribe therapy, as well as educate patients, under the guidance of a medical officer. Such services are conventionally offered on an outpatient basis (eg, the Antithrombosis Center, University of Illinois Medical Center, Chicago, Ill, USA) or within the general practice setting, and are effective and safe models of care. Patient self-management using point-of-care testing devices has also been studied overseas,3 with reports of good control of international normalised ratio (INR) and high patient satisfaction. Locally, point-of-care testing has been trialled within community pharmacies. In a Sydney-based study, trained community pharmacists monitored INRs using point-of-care testing, reviewed doses according to standardised nomograms, and subsequently liaised with GPs regarding dose adjustments. The results showed that collaborative management effectively maintained INRs within the therapeutic range.4 There is scope to develop such models further, and we are currently investigating GPs’ preferences for models of care, as well as opportunities for mobile anticoagulation services.
References
- New South Wales Health Department. Guidelines for prescribing, dispensing and administering warfarin. Safety Notice SN: 006/07. 12 April 2007. http://www5.health.nsw.gov.au/quality/sabs/pdf/SN00607_warfarin.pdf (accessed Aug 2007).
- Macgregor S, Hamley J, Dunbar J, et al. Evaluation of a primary care anticoagulant clinic managed by a pharmacist. BMJ 1996; 312: 560. 0_pgfId-1368103
- Cromheecke M, Levi M, Colly L, et al. Oral anticoagulation self-management and management by a specialist anticoagulation clinic: a randomised cross-over comparison. Lancet 2000; 356: 97-102. 0_BABIDCGC
- McLachlan AJ, Spindler M, Fois R, et al. A community pharmacy based anticoagulant management service. Canberra: Pharmacy Guild, 2005. http://www.guild.org.au/research/project_display.asp?id=255 (accessed Aug 2007).