Preventive Measures
It goes without saying that if you know the particular factors that worsen your asthma, you should reduce your exposure to them as much as possible. For example, airborne irritants that are known to trigger bronchospasm, such as cigarette smoke, should be avoided. And since there is evidence that marijuana smoke may be twenty times more irritating than tobacco smoke, avoidance of this substance is especially prudent. Likewise, whenever possible, exposure to fumes from insecticides, hair sprays, deodorants, paints, and perfumes should be minimized. In this regard, the use of air conditioners, humidifiers, and air filters can be extremely helpful.

If feasible, you should also avoid those foods and medications that have been linked to asthma flare-ups. These include the food additive MSG, the infamous Chinese Restaurant Syndrome culprit, and the metabisulfites, which are common preservatives found in restaurant salads, many canned beverages and foods, fermented drinks, pickled vegetables, packaged dried fruits, and certain processed items such as potato chips.

A small percentage of asthmatic flare-ups have in the past been linked to exposure to azo dyes, which are coal tar derivatives used to color various foods and drugs. Tartrazine, also known as FD&C Yellow No. 5, is a well-known example. More recent studies have cast some doubt on the link between azo dye and asthma, however, and as of now, further investigation is needed.

Asthmatics must be especially wary of aspirin. As many as 10 percent of asthma suffers will experience a flare-up within thirty minutes of taking aspirin. And for reasons that are not entirely clear, those with a history of chronic sinus problems and nasal polyps are especially prone to this response. Adverse reactions may likewise be provoked by a number of aspirin-related medications, such as the nonsteroidal antiinflammatory drugs (NSAID) that are frequently prescribed for arthritis, musculoskeletal disorders, and menstrual problems. Familiar drugs in this category are, among others, Advil, Motrin, Anaprox, Naprosyn, Nuprin, Butazolidin, and Indocin.

Finally, if you have seasonal respiratory allergies, you would do well to seek treatment for them since the link between hay fever and the subsequent development of asthma is especially noteworthy. In fact, about 5 percent of children with hay fever go on to develop asthma, and as many as 40 percent of all hay fever sufferers are discovered by spirometry testing to have some form of asthmalike findings.

Specific Therapies
Unfortunately, only the mildest cases of asthma respond to preventive measures alone. Most require some form of medical therapy. Today, the most common forms of asthma medication include bronchodilators, sympathomimetic agents, mast cell stabilizers, and corticosteroids. The use of these therapies, either alone or in various combinations, has afforded millions of people relief from what would otherwise be a debilitating, if not life-threatening, disease.

Since constriction of the breathing tubes is one of the hallmarks of asthma, bronchodilators, which are medications aimed at opening up the airways, make up one of the mainstays of asthma therapy. Asthmatics appear to possess in their lungs an inadequate amount of an important chemical known as cyclic adenosine monophosphate, or CAMP for short, which is responsible for normal airway opening. Bronchodilators work by interfering with the enzyme in the lungs that normally breaks down CAMP, in this way increasing CAMP levels and promoting more normal airway passages.

Medications containing theophylline or its derivatives are probably the best-known types of bronchodilators, and with the availability today of short, intermediate, long, and twenty-four-hour preparations, we are fortunate that doctors can tailor the dose and frequency of these drugs to the specific needs of most patients. Those with mild cases generally profit from the shorter-acting varieties, while those with more chronic asthma may benefit from the longer-acting ones. Examples of short-acting preparations include Aminophyllin, Bronkodyl, Slo-Phyllin, and Elixophyllin. Intermediate theophyllines include theophylline SR, Slo-Phyllin SR, and Theolair SR. Long-acting preparations include Theo-Dur and Slo-bid. Theo-24 and Uniphyl are two twenty-four-hour bronchodilators. Doctors often order periodic blood tests on patients who are taking these drugs to determine whether the level of theophylline in the bloodstream is within the desired therapeutic range.

Hormonelike drugs known as sympathomimetic agents are a second major class of antiasthma medication. These work to promote airway passage by stimulating an enzyme necessary for increasing CAMP levels. The name Adrenalin, or epinephrine, will be immediately recognized by anyone who has ever gone to the emergency room for treatment of a severe asthma attack. Usually given intravenously or by injection under the skin, epinephrine has literally been a blessing in emergency situations, although it is not for day-to-day use.

When reading about sympathomimetics in product literature or package inserts, you may come across the term selective heta-2 activity. All this means is that the drug has been formulated to work specifically where it is needed on certain chemical sites, known as the beta-2 receptors, located within the smooth muscles of the airways. Nonselective medications, by contrast, may affect all beta receptor sites in the body, including those within the heart where they may be responsible for such unwanted side effects as elevated blood pressure and heart rhythm abnormalities. Happily, a wide variety of selective sympathomimetic agents have been developed for daily use and are available by prescription in tablet, syrup, nebulizer (a machine that converts a liquid to a mist), or spray formulations.

Inhaled bronchodilators must be used properly to ensure maximum benefits. Most come as metered dose inhalers, which are hand-held, pocket-sized canisters that deliver the medication via the mouth directly into the breathing tubes. For optimal effect you need to get most of the medication deep into the lungs. In order to do this, you should keep the canister about two inches from your mouth rather than closing your lips around the mouthpiece, which is the natural tendency. By doing so, larger droplets from the inhaler are given a long enough distance to travel so that they break up into smaller droplets, which are better able to penetrate the narrower, more deeply situated branches of the breathing tubes. Alternatively, you may purchase a spacer device, a small tubular attachment for the inhaler that provides the optimal spacing for droplet breakup. Whatever the method of aerosol delivery, you must inhale the medication for three to five seconds and then hold your breath for up to ten seconds. Those with exercise-induced asthma might receive greater benefit by administering their dose about fifteen to twenty minutes before planned workouts.

Doctors usually take the patient's age and the severity of the condition into consideration when choosing the form and dosage of medication. Many specialists prefer metered dose sprays because the right amount gets to precisely where it is needed the most and with a minimum of side effects. Syrups are usually reserved for young children and adults who are unable to swallow pills. Nebulizers are used for very young children or the very elderly who are unable to manage sprays. Proventil, Ventolin, Brethine, Bricanyl, Alupent, and Metaprel are commonly prescribed forms of beta-2 sympathomimetic agents.

Many physicians advise against the use of over-the-counter, fixed drug combinations of theophyllines and sympathomimetics, such as Primatene "P," Tedral, and Marax. For one thing, many of them contain the sympathomimetic agent ephedrine, which is not a selective beta-2 agent and therefore unnecessarily affects the heart. A second, no less important reason is that such combinations do not permit the flexibility of dose adjustment of the individual ingredients to meet the specific needs of an asthma sufferer. This means, for example, that a person may get too much or too little of different components. In addition, combination products may contain unnecessary ingredients. They often contain, for example, phenobarbital and antihistamines, additives that contribute little to their overall effectiveness while they increase the likelihood of adverse reactions.

Anticholinergics are another class of bronchodilators worthy of mention. These agents work by blocking the effects of the hormonelike agent acetylcholine on the airways. Normally secreted by the vagus nerves of the lungs, acetylcholine is responsible for increasing airway constriction and mucus production. Anticholinergics, such as the Atrovent inhaler, have been found to be very useful for maintenance therapy rather than for acute treatment.

Cromolyn sodium (for example, Intal) is another very important drug in your doctor's antiasthma armamentarium. Neither a theophylline nor a sympathomimetic, the drug is believed to work by several important mechanisms. Most important, it blocks mast cell release of histamine, thereby reducing inflammation and alleviating any underlying allergic components of the asthma. Through an indirect mechanism, it may also raise CAMP levels and reduce bronchospasm. Finally, it is believed to possess a separate, direct antiinflammatory action that is capable of further reducing tissue swelling and sensitivity In general, cromolyns have been shown to have few side effects and are remarkably well tolerated.

Unfortunately, cromolyn is not useful for acute attacks. In fact, it may take as long as two to three months to build up adequate therapeutic levels of it in the blood to be effective. These drugs are occasionally used alone, but more commonly their use is combined with theophyllines or sympathomimetics. They have proven especially helpful when taken before workouts to control exercise-induced asthma.

Systemic corticosteroids, such as prednisone and prednisolone (Medrol), especially when used for short periods of time under strict medical supervision, are remarkably effective agents for reducing asthma symptoms. Among their many complex actions and interactions, they are potent hormonelike antiinflammatory agents and stimulators of CAMP None of these agents should be confused with the much-talked-about anabolic steroids used illegally by body-builders and athletes to increase muscle mass and performance. Side effects of prolonged, high-dose systemic corticosteroid therapy include the development of cataracts, gastrointestinal ulcers, osteoporosis (loss of bone calcium and vulnerability to fractures), potassium loss, and a slightly increased susceptibility to infection. Owing to this potential for adverse reactions, these medications are generally reserved for more difficult or more severe cases of asthma.

Alternate-day steroid therapy has proven to be an important means of maintenance control and of minimizing side effects in some chronic asthmatics. On an alternate-day steroid schedule, an individual takes his dose every other day rather than every day. This regimen, which has proven satisfactory in many patients requiring long-term systemic corticosteroid therapy, permits a day's respite for restoration of the body's normal hormonal balance, usually without significant worsening of any symptoms on these days.

The use of corticosteroids locally, in spray form, is another way to reduce potential side effects. Azmacort, AeroBid, Beclovent, and Vanceril are four popular sprays containing different types of steroids. Because they are inhaled directly into the breathing tubes rather than ingested and carried in the bloodstream, steroid sprays essentially work where they are most needed and have little effect on the rest of the body. As a result, many physicians currently prefer them when steroids are felt to be necessary.

Although antihistamines are the premier drugs for the treatment of most allergies, they play only a small role in the management of asthma. In fact, because of their ability to dry up secretions, antihistamines were at one time avoided entirely for asthmatics because of the fear that they might worsen plugging and clogging of the small airways. More recent studies suggest otherwise, however. Nowadays, when an individual's seasonal or perennial allergies are believed to be a major trigger of asthma attacks, antihistamines may be prescribed as part of the treatment regimen for alleviating both the upper airway congestion and the nasal drip that can complicate an asthma attack.

Lastly, unless there is some concern about superimposed infection, antibiotics play a limited role in asthma therapy. In the event that you are feverish and are bringing up thick greenish or yellowish sputum, your doctor may prescribe a short course of any of a number of different antibiotics, including tetracyclines, erythromycins, and penicillin derivatives such as Amoxicillin. Bear in mind, however, that antibiotics are antibacterial agents and are of no benefit against viruses, the causes of the common cold, flu, and some cases of bronchitis. For this reason it is best to consult your doctor before taking any antibiotic that you may find in your medicine cabinet. You should make sure that you are using it appropriately and for the right kind of infection.