Starting patients on a single antihypertensive drug and ‘titrating up’ to achieve blood pressure control might soon become an outdated approach, according to new research published in The Lancet.
Instead, a combination of four drugs, each at a quarter of usual dose, may be a faster route to optimal blood pressure management.
Professor Clara Chow, director of the Cardiovascular Division at The George Institute for Global Health, said the quadpill helped address issues such as low adherence rates and treatment inertia.
“Usually a GP sees a patient and starts them on a single drug. Six weeks later they might add in another drug or increase the dose of the first drug. Six weeks later they add in another drug. There are multiple steps and time wasted before blood pressure is under control,” she told the limbic.
“However, a lot of patients stay also on monotherapy and remain effectively uncontrolled,” she added.
The quadpill – a combination of irbesartan, amlodipine, hydrochlorothiazide and atenolol delivered in a capsule – was trialed against placebo in a small proof-of-concept study of 18 patients with untreated high blood pressure.
The study found all patients achieved an office blood pressure less than 140/90 mm Hg with no serious adverse effects. The mean reduction in office blood pressure was 22/13 mm Hg and 19 mm Hg in 24-hour systolic blood pressure.
Professor Chow said evidence from dual treatments – such as angiotensin ll receptor blocker and diuretic combinations – showed there was an additive effect in terms of efficacy and fewer side effects than any one drug at full strength.
“Each drug targets a different mechanism to lower blood pressure so this combination of four quarter doses is better than any one tablet. There is a synergistic effect at work,” she said.
A NHMRC funded study of the quadpill versus usual care will be commencing in three sites in couple of weeks.
Analysis at 12 weeks will look at the blood pressure and early side effects while a 12-month follow-up will provide information on long-term issues including side effects.