A high number of patients prescribed ß-blockers for heart failure, angina or after a heart attack stop taking the drugs within a few years, UK researchers have found.
After one year, a quarter of patients started on the drugs are no longer taking them. By three years this rose to 50% of patients, in results the researchers called ‘astounding'.
The high rates of discontinuation were the same whether the drug was prescribed for prognostic or symptomatic reasons, the data from 12,500 primary care patients in the General Practice Research Database showed.
The study also found that a quarter of those eligible for treatment with ß-blocker were not prescribed the drugs despite no documented contraindication. The results also suggest many patients may not be receiving the most effective dose, with 60% not uptitrated to the recommended levels.
Study leader Dr Paul Kalra, consultant cardiologist at Queen Alexandra Hospital in Portsmouth, said he was ‘astounded' to find such high rates of discontinuation, especially when the figures were conservative estimates.
He said: ‘There is a lot of caution around use of ß-blockers, and some of it is a lack of confidence. There is a perception that for some people there are contraindications, such as in COPD, when that definitely is not the case. And the drugs do have side-effects.'
But he said it was important patients were informed that the benefits of the drugs were accrued over time, and while they may feel worse initially that will pass.
‘There is a 35% risk reduction in mortality with these drugs and we need to think very carefully before stopping them. You wouldn't dream of stopping chemotherapy,' he added.
One problem is when people are admitted to hospital and non-specialists stop their ß-blocker prescription, he explained.
Dr Ahmet Fuat, a cardiology GPSI in Darlington, County Durham, agreed the discontinuation rates shown in the study were very high.
He said: ‘We do need to do a bit more work to understand why. I do think, though, that despite evidence for their use in heart failure and angina, there are a lot of doctors unwilling to persevere with ß-blockers who still worry about side-effects and their use in certain patients.'
He added that education was one aspect of solving the problem and also more use of heart failure clinics in primary care, where specialist nurses had the time to work with patients to support them in sticking with medication.
‘ß-blockers often have a bad name, and patients on the older drugs used to get a lot of side-effects that younger patients will have heard about from relatives. It is about talking with them about that they may feel worse initially, but that will improve – and in the long term, it will benefit them,' he said.
Int J Cardiol2012, online 25 July
