Patients not sticking to antihypertensives, report finds
Half of patients on antihypertensives stop taking them within a year and on any given day patients miss around 10% of scheduled doses, a team of European and US researchers report.
Data from 4,800 patients taking part in 21 clinical studies showed that of those missing doses, around 40% missed a single dose but another 40% missed several days' doses at once.
Patients who took ‘drug holidays' and missed sequential doses were most at risk of giving up treatment early and should be actively targeted to try and motivate them to continue treatment, said the researchers, writing online in the BMJ.
Study leader Dr Bernard Vrijens, chief scientist at the Pharmionic Research Center in Vise, Belgium, said the ‘shortfalls' in drug exposure that these dosing errors created might be a common cause of poor blood pressure control and high variability in responses to prescribed drugs.
‘These results also emphasise the importance of correctly identifying whether the mode of non-adherence is poor execution or non-persistence,' he said.
‘Patients who execute poorly need help in integrating their daily dosing into their routine, whereas patients who are at risk of imminent discontinuation need reinforcement and re-motivation to continue with treatment.'
Dr Brian Crichton, a GP in Solihull and honorary senior lecturer in clinical pharmacology at Warwick University Medical School, said the most expensive drug is one the patient does not take or does not take properly.
‘Concordance is an important issue and we are in a position to spot patients who are taking their medication irregularly. If patients have missed doses their blood pressure will swing and it only requires small changes to cause significant increases in risk.'
He advised GPs to stick to the simplest regimen in those who struggled with adherence and to routinely reinforce the importance of sticking to it.