Men living alone have more difficulty taking the blood thinning drug Warfarin than women, according to research presented this week at the 2019 World Congress of Cardiology.
Dr Anders Bonde from Gentofte University Hospital in Copenhagen said the study suggests men are more dependent on their partner than women when it comes to anticoagulation control. Of particular interest to pharmacy is Dr Anders’ belief the study indicates men who live on their own may need extra support to use warfarin, such as education, home visits, telephone contacts, or additional follow-up visits.
Warfarin is a common anticoagulant treatment for preventing stroke in atrial fibrillation, the most common heart rhythm disorder. Any difficulty patients may experience in dosing accurately is of concern as continuous blood-monitoring with international normalised ratio (INR) measurements is required for warfarin to be safe and effective. Too little of the drug may allow a blot clot to form and cause a stroke, while too much causes bleeding.
Quality of INR control is usually measured as time in therapeutic range (TTR), meaning the percentage of time with optimal warfarin concentrations in the blood to prevent stroke and avoid bleeding.
Guidelines advise being in the therapeutic range at least 70 per cent of the time however Warfarin can be challenging for patients, with dose adjustments needed to maintain high TTR coupled with a number of food and drug interactions.
The study found that the median TTR in men living alone was 57 per cent and well below the optimal therapeutic range. After adjustment for other factors known to be important for TTR, this was still significantly lower – by 3.6 per cent – than in cohabiting men.
“Men living alone had low poor anticoagulation control. The impact of living on their own was larger than several factors previously known to affect TTR, such as cancer, use of interacting medication, or heart failure”, Dr Bonde said.
“Women living alone often have better relationships with children or a broader network of people who could help them manage a demanding medication like Warfarin. Furthermore, divorces are often more difficult for men than for women, and the largest percentage of patients with diagnoses related to alcohol abuse, which is known to be important for anticoagulation control was found in men living alone in our study.”
The study involved a total of 4,772 atrial fibrillation patients with six months of continuous Warfarin use and INR monitoring, identified from Danish registers. Patients were divided according to sex and whether they lived alone or with others.