MONDAY, Jan. 10, 2005 (HealthDayNews) -- Asthma patients and their doctors can rest assured that most of the many aerosol inhalers on the market are equally effective if used properly.
So decisions on which ones to use should be based on ease of use and cost, new recommendations state.
The recommendations are based on a set of guidelines for the selection of aerosol inhalers that was released Monday by the American College of Chest Physicians and the American College of Allergy, Asthma & Immunology.
It's the first time guidelines, which were based on a review of some 60 studies of the efficacy of different aerosol devices, have been offered to doctors and patients involved in asthma treatment.
"There are a lot of devices on the market in all categories, and there was a lot of confusion about which ones to use," explained Myrna B. Dolovich, an engineer and associate professor of medicine and radiology at McMaster University in Hamilton, Ontario. She was chairwoman of the committee that reviewed the devices.
The recommendations appear in the January issue of Chest.
Since the 1950s and 1960s, the treatment of choice for asthma sufferers has been aerosol devices that allow medicine to be inhaled directly into the lungs, thus achieving high drug concentrations in the lungs and reducing systemic adverse effects throughout the body.
Hospitals and in-house health settings often use nebulizers, larger machines that effectively deliver medicine to acute asthma sufferers. However, the most popular inhaler device, used by approximately 70 percent of asthma sufferers, is a pressured, metered-dose inhaler (MDI), which lets a patient spray medicine into his or her mouth and then inhale it deep into the lungs. Because it's important that the spraying of the medicine and inhalation be coordinated, MDIs are often used with open-tube spacers that make it easier to do this, especially in younger patients, Dolovich said.
Introduced more recently, and gaining in popularity, are dry powder inhalers (DPIs), in which medicine in powder form is activated when the patient breathes in and doesn't need to be coordinated with spraying, Dolovich said.
With so many devices to choose from, Dolovich said, many doctors rely on "device efficacy" -- the stated amount of drug that gets into the lung -- when selecting treatments for their patients.
However, it's equally important that patients be instructed in the proper use of whatever device the doctor prescribes, because up to 70 percent of patients using MDIs fail to use them properly, she said.
"A patient has to know how to use the device and be competent enough to take the medication," she said.
Dolovich acknowledges that it can be difficult for busy doctors to take the time to train their patients to use the aerosol inhalers, but she said, "You can't hand over a device without checking if it's useful or not."
Further, she said, "Patients should know as well that if they're not getting relief with their medicine they should not hesitate to phone the doctor and say, 'It's not working,' and try another device."
Another consideration, she said, should be cost, which necessitates knowing which medicines and devices are covered by the patient's insurance policies.
Dr. Meyer Kattan, a professor of pediatrics at Mount Sinai School of Medicine in New York City, agreed with Dolovich that the patient's response to the medicine is key when choosing a device.
"Drug salesmen come around and tell you this drug is better because it has less side effects or is delivered more efficiently, but these differences are so minute," he said. "What's important is the patient's competence in using the device and their preference. It's difficult to take medicine every day, and the thing is not to give them medicine they don't like."
Approximately 17 million Americans, or 6.4 percent of the population, suffer from asthma, according to the National Institute of Allergy and Infectious Diseases. Asthma is an allergic reaction to substances commonly breathed in through the air, such as animal dander, pollen or dust.
When people who are allergic to a substance breathe it in, the immune system treats it as a harmful invader and produces a molecule called immunoglobulin E (IgE), an antibody to fight the substance. This, in turn, can cause the airways to become inflamed and constricted, leading to coughing, wheezing and difficulty breathing.
More information
The Mayo Clinic explains the different types of asthma inhalers.
