Asthma sufferers may soon only have to juggle a single inhaler.
New research conducted by Australian and Kiwi researchers has found combining the preventer and reliever inhalers into one reduces the chance of an attack by nearly a third.
"I went from having once to two asthma attacks per week to having none at all for that whole year - the improvement was incredible," said Upper Hutt asthma patient Kelly Gee, who took part in the year-long trial.
"I used to get pretty stressed if I left home and forgot my inhaler or left it in the truck. The constant worry about having an unexpected wheezing attack was always there."
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Around one-in-six Kiwis suffer from asthma, one of the highest rates in the world.
The study saw 890 adults split into two groups - half were given the new combined inhaler and told only to use it whenever they had symptoms, while the rest were told to keep using the preventer twice daily, and the reliever when they had symptoms.
The former group suffered 31 percent fewer attacks, despite inhaling about half as much of the corticosteroid substance which prevents attacks.
"This novel approach simplifies treatment as it doesn't require patients to take a preventer inhaler twice daily even when they have no symptoms," said Medical Research Institute of New Zealand director Professor Richard Beasley.
"It also addresses two key problems in asthma management - the reluctance of doctors to prescribe regular preventer inhaler therapy and the reluctance of patients to use it when they feel well.
"With a combined preventer-reliever inhaler, patients have more personal and immediate control over their asthma management. This takes advantage of the patient's natural behaviour to take a reliever only when they are experiencing symptoms."
The study was funded by the NZ Health Research Council. Acting chief executive Vernon Choy said it could "make a genuine difference for New Zealanders and people who live with asthma worldwide".
Severe asthma sufferers may need to stick to the traditional twice-daily applications, the researchers say, but the the combined inhaler could still be used for this, rather than having to keep two separate devices.
Since the trial, Gee's doctor has kept him on the combined inhaler treatment.
"It was very humbling to be involved. The findings are so promising and it's pretty nice to know that this will improve the health of hundreds and thousands of asthma sufferers all over the world and hopefully reduce their wheezing attacks the same way it did mine."
The was published on Saturday in The Lancet.