A new combination of four blood pressure drugs — the ‘quadpill’ — could be twice as effective as existing treatments, according to research by the George Institute at Sydney University (see our analysis below).
Of the 17 million British people who have been diagnosed with high blood pressure, most of whom take one drug, only about half see their blood pressure fall to healthy levels. All 18 patients in the study, which has been published in the Lancet, had healthy blood pressure levels within a month.
During the study patients were given a single capsule containing a quarter-dose of four common blood pressure drugs: amlodipine, irbesartan, hydrochlorothiazide and atenolol.
The researchers say that, although the dose of each drug is lower, combining them increases their effectiveness.
Taking a reduced dose of each drug also appears to lessen their side effects, which can include kidney problems, lethargy and swollen ankles.
The Mail Online said the quadpill was a ‘miracle drug’ that ‘cured’ high blood pressure.
The study’s lead author, Professor Clara Chow, said: ‘Most people receive one medicine at a normal dose but that only controls blood pressure about half the time. In this small trial blood pressure control was achieved for everyone. Trials will now test whether this can be repeated and maintained long-term.
‘Minimising side effects is important for long-term treatments — we didn’t see any issues in this trial, as you would hope with very low-dose therapy, but this is the area where more long-term research is most needed.
‘This could be an incredibly important step in helping to reduce the burden of disease globally.’
This was a randomised controlled trial of the kind often called a ‘pilot study’, usually a preliminary trial performed prior to a larger, more definitive study, looking at the utility of using a pill consisting of more than one antihypertensive medication.
Hypertension is a major cause of cardiovascular disease including stroke, myocardial infarction and blindness and control of it can often be challenging, particularly when a patient requires more than one drug to maintain blood pressure below the harmful range.
The results were interesting, with a definite superior effect of the multi-drug pill compared to placebo, reaching statistical significance. Both systolic (upper blood pressure number) and diastolic (lower blood pressure number) were significantly lowered in a variety of measuring situations, including ambulatory readings that more closely reflect everyday measurements as well as ‘clinic-based’ readings which are often elevated due to the anxiety of the patient.
Weaknesses of the study include the short follow-up period, which is not long enough to assess clinical effects resulting from improved blood pressure control and, of course, the small sample size, which limits generalisability of the excellent side effect profile but also control of blood pressure.
Regular readers will recall the difference between clinical significance and statistical significance; this study is not sufficient to allow any conclusions applicable to everyday clinical practice; for that we await the larger, multi-centre RCT with adequate power (sample size) to detect side effects as well as clinical effects.