Asthma revisited – includes related article on anti-asthma drugs
Since Health News last discussed asthma in 1987, concepts of the disease and its management have changed greatly. Asthma is now regarded primarily as a persistent inflammatory condition that produces unusually sensitive or “twitchy” airways (breathing tubes), possibly leading to severe, sometimes fatal, breathing problems. While bronchodilators or airways widening drugs are still essential, modern experts promote earlier and greater use of anti-inflammatory medications to suppress the underlying airway inflammation. Childhood astham therapy now also relies more on anti-inflammatory medication and easier-to-use inhalers. The development of new inhaler delivery systems (such as “spacers” and breath-activated “powder-puffers”) makes anti-asthma drug easier to use.
Greater emphasis on reducing airway inflammation
Inflammation of the airways is now considered a key problem in asthma, even in newly diagnosed, mild or minimally symptomatic cases. Two main processes participate in asthma, each needing different treatment. The first is transient airway narrowing due to bronchial smooth muscle contraction, which requires and responds rapidly (within minutes) to an inhaled airway-widening drug or bronchodilator. But while the shortness of breath may subside in a couple of hours (or within minutes) of inhaling a bronchodilator), the asthmatic reaction is generally not over when the breathing difficulties vanish. The second stage of asthma is long term, chronic airway inflammation which takes some hours to develop but may last for weeks, even though obvious symptoms are gone. Untreated, the inflamed, swollen, reddened, “hyper-responsive” (twitchy) airways can become seriously obstructed.
While bronchodilator drugs swiftly widen narrowed breathing tubes and relieve the chest tightness, they do nothing to reduce the airway inflammation. The current trend is therefore to use anti-inflammatories (particularly) inhaled corticosteroids) sooner and more liberally to quench the underlying inflammations. Studies confirm the advantages of inhaled corticosteroids over bronchodilators for mild to moderate asthma. However, asthmatics need reassurance about the safety of corticosteroids because of bad press about their side effects. Since inhaled steroids act locally on the airway tubes, little is absorbed into the bloodstream, producing negligible side effects at usual doses.
Baffing rise in asthma deaths
Yesterday’s generation considered asthma a relatively mild disorder, afflicting mainly children, like “Piggy” in the Lord of the Flies — a viewpoint becoming obsolete as more people now develop asthma in their teen and adult years. Not only are more people being diagnosed with asthma, but complacency about its “harmless” nature has been shattered by a steep rise in hospital admissions and deaths. The incidence of asthma has been rising at the rate of about six percent a year since the early 70s, and deaths have gone up by about 30 per cent in the past 10 years in many industrialized countries. According to Statistics Canada, 10 people die each week from the disability, mainly young Canadians aged 15-34. For every asthma death there are hundreds of cases needlessly out of control, requiring better therapy. These figures don’t mean that asthma is a common cause of death, even for asthmatics, but because asthma deaths are almost always preventable, it’s far too high. Those who die from asthma have often had ample warning of possible problems: previous life-threatening episodes, recent hospitalizations for a severe attack or poorly controlled symptoms.
Nobody knows exactly why more people are dying of asthma, not only in Canada but also in Britain, the U.S., New Zealand and other countries — despite more available medications (or perhaps because they’ve wrongly used). But there are several postulated reasons for the upturn. One is air pollution, as asthma often worsens in summer when ozone and other pollutant levels rise. But against this theory is the fact that New Zealand — which has less polluted air — has more asthma deaths per capita than Canada. Other suggested reasons are the failure of physicians to recognize the disease early, failure of asthmatics to follow the prescribed treatment, over-reliance on certain drugs (airway-widening bronchodilators) and under-treatment with others (anti-inflammatories). Many asthmatics rely too much on bronchodilating medication to relieve troubled breathing, remaining unaware of their worsening condition, often waiting too long before seeking medical help. Many go for medical aid only hours after self-administering large amounts of their usual quick-relief bronchodilator, hoping that what works for a mild attack will ease a severe one. They may reach the emergency room too late or die en route to hospital.
Another possible reason for increased fatalities is failure by healthcare personnel to recognize the severity of an attack, not giving enough anti-inflammatories (steroids) quickly enough and discharging asthmatics too soon without proper medicines and instruction. Relapses often occur shortly after a bad attack that hasn’t been adequately treated. One University of Toronto expert lists the “two absolute requirements for treating emergency asthma as: measuring the extent of airflow obstruction (to check severity) and immediate use of corticosteroids.”
Education as vital as asthma drugs
Asthma affects about 10 per cent of Canadians. Asthmatics often get into trouble for lack of knowledge about their disease and denial of the need to take medications. Many think their condition is “just an irritation”, or can be treated “with cough syrups and antibiotics.” Surveys shows that asthmatics who are conscientiously taught about their disease and the value of medications achieve far better control than those who get no tuition. As detailed in the December 1987 issue of Health News, asthmatic airways are hyper-responsive and easily narrowed in response to various stimuli. Asthma may arise from specific “triggers”, some of which cause an allergic response. Many substances or stimuli–such as exercise, cold air, the presence of animals (e.g. cats, rabbits, birds), viral infections, bronchitis or sinusitus — may set off asthma. In allergic asthma, attacks are triggered by specific allergens or substances to which the person is sensitized, such as animal dander, cockroach remains, pollens, molds and dust mites. But about 50 percent of asthmatics have no known allergies. The classic asthma attack surfaces with wheezing, a constricted chest, coughing and excess phlegm. Getting air in and out of the lungs is troublesome and each breath may seem an immense effort. The severity of asthma varies from mild — with attacks spaced far apart (needing no more than one or two bronchodilator puff a day) — to severe, requiring regular, ongoing medication.
All asthmatics needs a personalized, treatment plan
Therapy varies from one asthmatic to another. Each asthmatic must have an individual treatment plan, be able to recognize worsening symptoms and know when to get emergency aid. It’s crucial to recognize warning sign early. Asthma may start out mild but get more serious. The first step is to identify and dry to avoid triggers that set off attacks. Some triggers can be modified; others must be accepted and lived with. Eliminating the source of the trouble can go a long way in clearing up the symptoms. For example, smoking asthmatics should give up tobacco; others might have to give away a household pet. Those exceptionally sensitive to dust mites might be helped by a dust-free living environment. Regardless of the best efforts to avoid triggers and create a “nonasthmatic” environment, many asthmatics also require regular medication. Different does and combinations of bronchodilators, non-steroidal and corticosteroid anti-inflammataroies will be tried in a stepwise manner. Modern therapy uses more aggressive anti-inflammatory treatment to reduce the need for bronchodilators. Bronchodilator rescue does shouldn’t be needed more than about twice daily. Asthmatics who use their bronchodilating drugs more than twice (or a maximum of four times) a day should be on other anti-inflammatory medications. The new focus on reducing airway inflammation has made older therapies not only out of date, but possibly harmful. Until recently, bronchodilators were routinely prescribed for asthma, but many experts now recommend their use only when symptoms occur, employing other preventive medications to keep symptoms away. Overuse of bronchodilators may mask worsening symptoms without ameliorating the underlying disease. (Some experts claim the regular over-use of bronchodilating drugs may wosen asthma in the long run.) With the emphasis on ashtma as an inflammatory disorder, inhaled corticosteroids, such as beclomethasone or budesonide, have moved into front line therapy. Many specialists now believe that all asthmatics who experience regular (daily) symptoms should be treated with inhaled corticosteroids as well as bronchodilators. A standardized approach to asthma treatment has been issued by Canadian experts, published in the June 1990 Journal of Allergy and Clinical Immunology (for adults) and the 1991 Canadian Medical Association Journal (for children). Very midl asthmatics often need no more than the occasional bronchodilator puff. If asthma symptoms occur more often, it’s likely time for anti-inflammatory medication. Non-steroidal preventives, such as cromoglycate (Cromolyn) or nedocromil (Tilade) may be the next step. If these drugs fail to control asthma after about six weeks, they would usually be replaced with inhaled corticosteroids. Severe symptoms and greatly reduced airflow rates call for an immediate and adequate “burst” of oral or intravenous steroids, gradually tapering down the amount. Once the person is relatively free of symptoms, the drugs will likely be reduced and/or discontinued one by one until the minimal drug balance with the least side effects is found — a result that may take several months and several doctor visits. Airflow rates should be measured and remain near normal. One University of Toronto expert suggest that “every asthmatic should have a cheap, portable, home peak flow meter to help monitor and manage the condition.” If asthma interferes with usual activities or sleep, treatment is inadequate and should be reviewed. Those whose asthma remains troublesome should request a second opinion from a specialist, local asthma centre or clinic. Simply tossing back more pills or taking more inhaler puffs is not a sensible way to handle this complex disease.
New inhaler devices make asthma drugs easier to use
Asthmatics must learn to use their inhalers correctly, follow the package insert instructions and remember that cold temperatures and humidity reduce their efficacy. (Keep the inhalers warm and dry!) Studies show that many asthmatics use their inhalers improperly. Ask your physician or pharmacist for a lesson. Whereas, older metered dose inhalers (MDIs) for asthma had to be pressed to deliver a measured dose of drug at the same time as breathing in — carefully coordinating activation with inhalation — the new puffers require less meticulous timing. There is now a wide range of inhalers to choose from, including spacers or aerosol-holding chambers (Aerochambers) and breath-activated “powder-puffers” (e.g., the Turbuhaler, Rotahaler, Spin and Dischaler) that spray in powder. The aim is to put as much of the drug as possible into the airways leaving as little as possible in the mouth and throat. Spacers avoid the need to activate the inhaler and breathe in simultaneously. The drug is released into a holding chamber, giving extra time to coordinate inhalation. Since breathing needn’t be as carefully timed, people who have difficulty with standard MDI inhalers (mainly the very young and the old) can use their drugs more effectively. The inhalers that use dry powder instead of aerosol products are another advance, requiring just a small click to release the drug before breathing it in.
Asthmatics need a definite (written) emergency plan
Even the milders of asthma can become severe under certain circumstances. Asthmatics must learn the signs of worsening asthma and know “what to do if…….” An asthmatics crisis plan suggested by Toronto’s Asthma Centre is a three-step process. First, on noticing worsening symptoms, the asthmatic doubles, triples or quadruples the usual dose of inhaled cortciosteroid. Inhaled corticosteroids can often relieve mild to moderate asthmatic worsening without the need for steroid tablets or emergency room visits. Second, if there’s no relief from inhaled corticosteroids, a tapering course of oral steroids may be advised. Asthmatics prone to troublesome episodes might keep steroid pills on hand for times of crisis — of course accompanied by a phone call to the physician. Third, if symptoms persists of worsen, go at once to the nearest hospital emergency.
Managing childhood asthma
As with adults, there’s now greater emphasis on treating childhood asthma with anti-inflammatory agents, aiming for freedom from wheeze, regular school and sports attendance and no sleep disturbance. One University of Toronto specialists defines childhood asthma as: “recurrent (three or more episodes) of wheezing and shortness of breath unless other causes are found.” Any child with recurring bouts of wheezing, shortness of breath or coughing should be checked for asthma. Asthma in children is more likely than in adults to involve severe attacks that develop rapidly, in a few or hours — sometimes with no prior warning — possibly triggered by a viral infection. About 75 per cent of childhood asthma is mild, with sporadic wheezing and/or cough, usually well controlled by no more than twice daily bronchodilator puffs. Additional treatment is needed for children who whezze with exercise, on exposure to the cold, dust mites, animals or other triggers. About 20 percent of asthmatic children have moderate disease, with episodes every four to six weeks, for whom inhaled cromoglycate or ketotifen (Zaditen) tablets or syrup are usually advised. If this regime doesn’t keep sumptims down after a few weeks (longer in very young children), an inhaled corticestorid may be suggested. The five per cent or so of severely asthmatic children with breathing trouble on most days (serious enough to interfere with school and sleep) need regularly inhaled corticosteroids plus brochodilators for “breakthrough” wheezing. Studies show few no toxic side effects from regular, low-dose inhaled corticosteroids in children.
COPYRIGHT 1992 Strategic Inc. Communications Ltd.
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