Posts Tagged ‘asthma management’

Theophylline
Theophylline-type drugs are also known as xanthines or methylxanthines. These drugs are chemically similar to caffeine. They cannot be inhaled, so are taken as tablets or syrup. They start working about 30 minutes after being taken and their effects last for 6-8 hours. Slow-release preparations take 90 minutes to start working, but they last 12-24 hours, and are therefore useful for nocturnal asthma.
In Britain, doctors generally regard theophylline-type drugs as reliever drugs (see p. 152), but rather risky ones whose use is only justified for people with severe asthma. They are given, as an additional treatment, to asthmatics who are not responding well to the usual drug programme (see p. 160). Unfortunately, fairly high doses are needed for theophylline-type drugs to act as relievers, i.e. to reverse bronchospasm. There is a very narrow margin between such a dose and one that causes major (and sometimes dangerous) side effects.
Such side effects usually occur when the doctor is still trying to work out the correct dose – this varies from one person to another, so prescribing theophylline-type drugs is no easy matter. Once you are established on a safe dose (and provided your general health and your intake of alcohol, nicotine and medicinal drugs does not vary – see p. 158) you can usually continue taking theophylline without serious side effects.
In the United States, many doctors also give theophyllinetype drugs, at much lower doses, to people with mild asthma. At these low doses they do not act as relievers, but they have a slight anti-inflammatory effect and therefore act as preventers. The risk of toxicity is much less. Taking low doses of theophylline allows people with mild asthma to reduce their use of beta-2 relievers. However, inhaled steroids are usually more effective in this role, and are the preferred treatment outside the United States.
Side effects
Typical side effects include nausea, vomiting, stomach pains, diarrhoea (sometimes with blood), headache, anxiety, restlessness, insomnia, dizziness, and a pounding heart or irregular heartbeat.
Any side effect of these drugs should be taken seriously and reported to your doctor as soon as possible. If you cannot get an appointment quickly, it may be best to stop taking the drug before seeing the doctor, as long as you have other drugs to control your asthma. Call your doctor for advice.
It is remarkably easy to overdose when taking these drugs at higher doses (see p. 157). Such overdoses can be fatal. The symptoms include repeated vomiting, shaking, feeling unusually hot, needing to urinate frequently, severe thirst, maniacal behaviour, and irregular heartbeat (palpitations). Delirium and convulsions may occur shortly afterwards, so get hospital treatment urgently if you have any of these symptoms.
Unfortunately, a serious overdose can sometimes occur in people who have taken theophylline-type drugs without trouble for many years. There may be no advance warning that anything is wrong - no mild side effects preceding the serious ones. To protect yourself against this, you need regular blood tests from your doctor.
One fundamental problem with theophylline-type drugs is that many different factors - including diet, illnesses other than asthma, and taking other drugs - can alter the way your body deals with the drug. If your liver is breaking down the drug more slowly than usual, the amount in your blood will rapidly increase, and can reach toxic levels.
These are steps that can help prevent an overdose with theophylline-type drugs:
• If you start taking a new drug of any kind, or stop taking a drug (especially the contraceptive pill), or if you change your intake of nicotine or alcohol, ask your doctor - preferably in advance - if your dose of theophylline-type drug needs to be changed.
• A great many drugs interact with theophylline-type drugs, including the new anti - leukotriene drugs. You should always be cautious with any new drug, but take particular care with two antibiotics - ciprofloxacin (brand name Ciproxin) and erythromycin (various brand names) - and with cimetidine (various brand names), used for stomach ulcers and heartburn.
• If you have flu vaccinations, or develop certain illnesses, especially viral infections, heart disease or liver disease, watch for the typical side effects of theophylline-type drugs (see above) and consult your doctor immediately if any occur. These conditions all change the effects of theophylline-type drugs.
• Don’t eat meals that are very high in fats or oils. A lot of fatty food causes too much of the drug to be released at once from the slow-release preparations and increases the risk of side effects. Avoid sudden, major, changes to your diet.
• See your doctor regularly for check-ups. Simply getting older changes your reaction to these drugs: your dose may need to change over the years.
• If you are at all forgetful about tablets, keep a careful record of when you have taken your theophylline-type drugs. Be very careful never to take a second dose by mistake.
• Talk to your doctor if you are not taking a slow-release form of theophylline (see box below for brand names). There are usually fewer side effects from these than from the ordinary forms of the drug.
• Wear a Medic Alert bracelet (see box on p. 95) saying that you are taking theophylline-type drugs. If you have a severe asthma attack and are taken to hospital, it is important that medical staff know this, so that they do not give you more drugs of this type.
While pregnant or breast-feeding, it may be advisable to stop taking theophylline-type drugs: discuss this with your doctor. Although the drugs do not affect most unborn or newborn babies, there are occasional reports of toxicity. Less seriously, theophylline-type drugs go through into breast milk, and may make babies irritable and restless. This problem can be solved by always taking the drug just after a feed - this reduces the amount in the milk.
Theophylline-type drugs might produce behavioural problems and learning difficulties in young children although this is unproven. Research shows that there are no problems for children over six.
Anti-IgE drugs
For asthmatics with strong allergic reactions, who are not doing well on ordinary treatment, the new anti-IgE drugs, such as omalizumab may be very valuable (see p. 149). They are given as a depot injection under the skin.
Some common brand names
Common brand names of theophylline-type drugs include: slow-release preparations — Lasma, Nuelin SA, Phyllocontin Continus, Slo-Phyllin, Theo-Dur, Uniphyllin Continus
ordinary preparations - Aminophylline, Nuelin Ketotifen
Ketotifen (brand name Zaditen) is an antihistamine (see p. 138), although it has other effects in addition to those of ordinary antihistamines. Most significantly, it stabilises mast cells in a similar way to cromoglycate.
One advantage of ketotifen to many people is that it is taken by mouth, in capsule, tablet or syrup form. When it was first introduced, doctors hoped that it would be of particular help in asthma, but it has not lived up to expectations. However, some asthmatics do find it effective. It is worth trying because, it it works, it could permit you to reduce your dose of steroids.
Ketotifen requires up to six weeks to take effect, so continue taking your previous drugs (e.g. steroids) for at least six weeks, or you will risk losing control of your asthma.
Side effects
Minor side effects from ketotifen include nausea, headache, increased appetite and weight gain, drowsiness, dry mouth and slight dizziness. Do not drive until you are sure that ketotifen does not make you drowsy. Alcohol may pack a more powerful punch than usual, so drink very moderately at first. If drowsiness is a problem, take the drug in the late evening. The sleepy feeling may wear off after a few weeks of taking the drug.
There are no serious side effects from ketotifen, except if taken with drugs for diabetes.
Anti-leukotriene drugs
Leukotrienes are among the messenger chemicals that are produced by mast cells during an allergic reaction (see box on p. 12). They help to perpetuate the inflammatory process begun by histamine, and they amplify the reaction by attracting more immune cells into the area.
The anti - leukotriene drugs fall into two distinct groups:
• those that bind to the receptors for leukotrienes, called leu kotriene- receptor antagonists. Currently, there are two drugs in this group, montelukast (brand name Singulair) and zafirlukast (brand name Accolate). A third drug, pranlukast, is in the pipeline and currently going through its safety trials.
• those that block the production of the leukotrienes altogether, called 5-lipoxygenase inhibitors. There is only one drug in this group at present, zileuton (brand names Leutrol, Zyflo); it is not yet available in Britain.
As regards tackling inflammation, the anti - leukotriene drugs work in a completely different way from either steroids or cromoglycate. This makes them useful as an add-on treatment, supplementing the effects of existing anti-allergy drugs.
For asthmatics, anti-leukotriene drugs may be particularly good in combination with antihistamines – whereas antihistamines alone are singularly unsuccessful in asthma (see p. 138). Recent research suggests that taking antihistamines together with antileukotriene drugs is an effective way to control airway inflammation. However, there have been no large-scale trials of this treatment option yet, and it may be a while before it comes into general use.
In the airways of people with asthma, leukotrienes can directly trigger bronchospasm (contraction of the airway muscles) as well as fostering inflammation and increasing mucus production. This multiple action of leukotrienes makes anti-leukotriene drugs very valuable for asthmatics because they act as both relievers (reversing bronchospasm) and preventers (tackling inflammation). They are especially useful for exercise-induced asthma.
All the anti-leukotriene drugs are taken in tablet form. If you are trying an anti - leu kotriene drug for the first time, don’t expect any noticeable effects to occur for about three days. Once you are taking the drug regularly, each dose requires 2-4 hours to have its full effect, but goes on working for 12-24 hours in total.
Although anti - leu kotriene drugs have a reliever effect, they cannot give you immediate relief from bronchospasm. Asthmatics must therefore carry a short-acting beta-2 reliever (see pp. 152-3) as well, in case of an asthma attack.
For those who dislike inhalers, or tend to forget to use them, the fact that these drugs are taken once a day in tablet form makes them an attractive option. However, they are expensive, and at present doctors prescribe them mainly for young children who have difficulty inhaling their usual drugs.
Side effects
The side effects noted in safety trials of these drugs were all minor ones:
• zafirlukast – headache, nausea, diarrhoea, pain
• montelukast – headache, diarrhoea, abdominal pain, cough, and flu-like symptoms
• zileuton – upset stomach
As with all new drugs, you should report any unusual symptoms to your doctor, just in case these represent a rare or longterm side effect of the drug (see p. 137).
Very occasionally montelukast provokes allergic reactions, with symptoms such as itchiness, widespread nettle rash (urticaria) or swelling (angioedema).
Zafirlukast and zileuton can both cause liver damage, but this is rare. Your liver function should be closely monitored by the doctor, by means of regular blood tests, and the drug withdrawn at the first sign of trouble. Montelukast can also affect the liver, but this is extremely rare.
The most worrying development noticed to date is the appearance, in a very few people taking zafirlukast or montelukast, of a disorder called Churg-Strauss Syndrome. The symptoms may include a blotchy purplish rash (due to vasculitis – see lower box on p. 73), a flu-like illness, worsening asthma, and numbness or tingling in the limbs. The heart, lungs and nerves are all affected, because eosinophils (see p. 19) are present in large numbers and cause damaging inflammation.
A study of the cases reported so far suggests that this syndrome may not be due to the anti-leukotriene drugs themselves but to other causes – usually (though not always) a reduction in the dose of steroids. Other patients who are not taking antileukotriene drugs, but are reducing or stopping steroids, may also (again, very rarely) develop Churg-Strauss Syndrome. Doctors now suspect that all these patients were already suffering from an underlying eosinophilic disease, which first showed itself simply as asthma, and was quelled by the steroid treatment prescribed for the asthma. The disease was thoroughly masked as long as the patient was using steroids, but when steroids were withdrawn, the underlying disease flared up, producing a wide range of symptoms. In most cases, reintroducing steroids brings these symptoms under control again.
Putting it all together
What is the ideal combination of all these asthma drugs? That is something your doctor can only work out slowly, because it varies from one individual to another.
The conventional approach to asthma treatment is to start patients on a short-acting beta-2 reliever and then, if the symptoms are not controlled, to add other drugs. This approach is called ’stepping up’. The standard steps, or stages, are as follows:
1. Use a short-acting beta-2 reliever only.
2. Add cromoglycate or low-dose inhaled steroids.
3. Try a higher dose of inhaled steroid or a long-acting beta-2 reliever.
4. Try out each of the following in turn: theophylline, anticholinergic drugs, cromoglycate and higher doses of beta-2 relievers (either inhaled or as tablets/syrup).
5. If there is still no success in controlling symptoms, add regular steroid tablets.
Short courses of steroid tablets may be used at any stage, for the control of sudden, severe, attacks.
Over the last ten years, there has been a change of strategy, and very few people are now kept on Stage 1. Inhaled steroids are now given to most asthmatics, even those with relatively mild asthma. Research from Sweden, where widespread use of
inhaled steroids first became general policy, shows considerable benefits to this approach.
If you have gone beyond Stage 2, ’stepping up’ is usually followed by ’stepping down’. In other words, when the symptoms have been well controlled for 3-6 months, doses of some drugs are reduced, or certain drugs stopped altogether. If the asthma flares up again, the dose is increased or the drug reinstated. If there are no problems, and symptoms remain stable for a month or two, another reduction is tried.
An entirely different approach to asthma management is now being tried with some patients – starting off with moderate to high doses of inhaled steroids (equivalent to Stage 3) and then ’stepping down’. The idea is to get the inflammation under control promptly and fully at the outset. This often seems to be the best strategy.
A few asthmatics don’t get much benefit from steroids. If your dose of steroid needs to be raised repeatedly, or you still need to use your reliever daily in spite of taking steroids, you may have steroid-resistant asthma. There are other drugs that can help, including anti-leukotriene drugs and the more powerful anti-allergy drugs (see p. 149).
Alcohol, caffeine and asthma
Some asthmatics experience bronchodilation (opening up of the airways) when they drink alcohol, while others experience
bronchospasm (tightening of the airways). For those whose airways open up, there is probably no harm in sometimes having a drink to relieve your asthma symptoms, assuming these are fairly mild. Clearly, it would not be a good idea to make a daily habit of this.
If your airways tighten up with alcohol, you will probably be pleased to hear that it may not be the alcohol itself. Alcoholic drinks contain a great variety of other ingredients, either derived from the original ingredients or generated during the fermentation process. Called ‘congeners’, these vary from one type of alcoholic drink to another, and they are often the culprits in asthma. So you may well find that, while one kind of alcoholic drink has a bad effect, another is fine.
Caffeine has a far more uniform effect — for most asthmatics it opens up the airways. However, the amount needed to relieve an asthma attack will also produce unpleasant side effects, such as a pounding heart or shaky hands. There are also long-term problems with such high doses of caffeine, including insomnia, headaches, nervousness and ‘restless legs’. It is much better to use your reliever inhaler to control an attack: the drug in the inhaler has been chemically tailored to give the maximum therapeutic benefit with the minimum of side effects. Anyone who consumes tea or coffee excessively can make themselves seriously ill, either physically or mentally, and it is not always obvious that caffeine is the cause (see p. 235).

Steroid inhalers
Most asthmatics nowadays are given a steroid inhaler at some point, as part of their asthma treatment (see p. 160). It will probably be a low-dose inhaler, and the risks of side effects from this are very small. Even at higher doses, inhaled steroids are relatively safe. Many people are unnecessarily afraid of inhaled steroids and refuse to use them until their asthma becomes really incapacitating. It is important not to delay using an inhaled steroid for too long, as this could cause permanent damage to the airways: inflammation eventually thickens the airway wall, leaving it less flexible and therefore less capable of widening.
For side effects of inhaled steroids see p. 145, and for common brand names see p. 147.
Steroid tablets
These are usually a treatment of last resort. But when you need them you need them – and if your asthma has got badly out of control, they can, quite literally, be a life-saver. On the other hand, if there are any other means by which you can tackle your asthma, so that you do not need steroid tablets again in the future –avoiding allergens and irritants, for example, or using other preventer treatments – those means should definitely be taken.
For side effects of steroid tablets see pp. 141-3, and for common brand names see p. 147.
Cromoglycate-type drugs
For asthma, these drugs are taken by inhalation only. They work by blocking the allergic reaction (see p. 148), and are therefore a type of preventer drug.
Cromoglycate-type drugs are usually inhaled four times a day, although your doctor may recommend more frequent inhalations to begin with. Once your asthma is well controlled, you may be able to reduce the dosing regime to three times a day, or possibly twice a day: ask your doctor’s advice about this.
Should you decide to stop taking these drugs at some point, talk to your doctor first. It is generally best to reduce the dose gradually, over a period of 7-10 days. Some asthmatics need to introduce (or reintroduce) steroids at this time, to maintain control of the airway inflammation.
Side effects
When inhaled, cromoglycate-type drugs can produce short-lived irritation in the throat, which may lead to coughing. This sometimes develops into temporary bronchospasm, causing you to wheeze, but this is really only a minor side effect – it does not indicate that the drug is making your asthma worse.
Asthmatics are sometimes advised to use a short-acting
beta-2 reliever (such as Ventolin) before their cromoglycate inhaler, to overcome this problem. However, this would involve using the beta-2 reliever four times a day, which is no longer considered a good idea (see pp. 153-4). Talk to your doctor again if you have been given this advice.
Inhalers that combine sodium cromoglycate with a short-acting beta-2 reliever (e.g. Aerocrom) are not recommended for the same reason.
A better way around the problem of throat irritation may be to switch to an aerosol inhaler, because the irritation is much less than with dry-powder inhalers. Using a spacer along with the aerosol inhaler (see p. 162) will help even more.
Serious side effects of these drugs are very rare (see p. 149). For common brand names, see p. 148.

Drugs for Asthma
The drug treatment of asthma is far more complex than for any other allergic disease. Drugs prescribed for asthma fall into two basic categories: those that open up the airways by relaxing the airway muscles, called relievers, and those that treat the inflammation in the lining of the airways, called preventers. The former offer a ‘quick fix’ - like taking an aspirin when you have a headache. Just as the actual cause of the headache is not treated by an aspirin, so the actual cause of the asthma attack is not addressed by relievers. Preventers, on the other hand, tackle the basic problem - the inflammation that triggers the contraction of the airway muscles (see p. 36).
In the past ten years, there has been a quiet revolution in asthma treatment, with far more people being given preventer inhalers, usually low-dose steroids. The aim is to get the airways in better condition, with the inflammation thoroughly damped down, so that the airway muscles don’t go into spasm. The ultimate objective is to make people far less reliant on reliever inhalers, because the potential hazards of over-using them are now realised.
The details of modern asthma management, and the different approaches used, are described on p. 160, following the discussion of the main types of drug used for asthma treatment.
Beta-2 relievers (beta-agonists)
Our airways open up when we produce adrenaline. This is the body’s natural response to feeling angry or frightened. The adrenaline widens the airways so that we can run faster or fight more vigorously.
Adrenaline (epinephrine), given as a drug, was among the earliest treatments for asthma. However, it also stimulates the heart to beat faster and raises
the blood pressure. While it is useful for emergency treatment (see p. 155) the side effects make it too hazardous for routine use.
The beta-2 relievers work by mimicking adrenaline – they bind to the same receptors in the airways, the beta-2 receptors. Binding to these receptors stimulates the airway muscles to relax, so that the airways open up.
In other respects, the beta-2 relievers are not like adrenaline. Clever chemical manipulation has made them sufficiently different from adrenaline to have little effect on the heart and other organs, when taken at normal doses.
Beta-2 relievers are best taken by inhalation. Although tablets and syrup are available these are far more likely to bring on side effects, because the dose needed is so much bigger.
Inhaled beta-2 relievers target the drug directly on the airways, so the dose can be smaller. They also have the great advantage of taking effect soon after being inhaled, and giving full relief from airway narrowing within 10-15 minutes.
There are two different kinds of beta-2 relievers:
•    the traditional short-acting beta-2 relievers whose effects last for 3-6 hours (usually about four). The modern consensus is that these should be used only when needed, not taken routinely.
•    the newer long-acting beta-2 relievers, which last up to 12 hours. These drugs are prescribed for more severe forms of asthma (see p. 154), and are generally used routinely, twice a day.
A key question for asthma sufferers is: How often can short-acting beta-2 relievers be used? Ideas about this have changed considerably over the last 20 years, and no doctor would now want to have patients using a Ventolin inhaler five, six or more times a day - something that was quite common in the past. This level of need for beta-2 relievers indicates that the asthma is poorly controlled and requires treatment with a preventer, to quell the inflammation in the airways.
Detailed policy on beta-2 relievers still varies from one part of the world to another. British guidelines state that anyone who needs to use a short-acting beta-2 reliever more than once a day, or who suffers from nocturnal asthma, should be given a preventer as well. The international guideline is more stringent: if a short-acting beta-2 reliever is needed more than three times a week, a preventer should also be prescribed.
How safe are these drugs in the long term? The cause of the big re-think on beta-2 relievers was an epidemic of asthma-related deaths in New Zealand between 1976 and 1988. The death rate from severe asthma attacks was 2-4 times its previous level for a while, and over a thousand New Zealanders died in the epidemic.
There has been a huge controversy over what exactly caused these deaths. Most researchers now agree that the main cause was a new brand of inhaler that delivered a double dose of the drug fenoterol, a short-acting beta-2 reliever with a very powerful effect on the airways and quite high levels of side effects involving the heart. The same brand of inhaler may have been linked to increased death rates in Canada and Germany.
Research suggests that the problem was greatest in New Zealand because sales of the new inhaler were highest there, and because many patients got their inhalers through repeat prescriptions. As a result, people whose asthma was deteriorating badly were not seen by a doctor and were using large amounts of beta-2 reliever, rather than taking preventer drugs. This is now believed to be a major cause of asthma deaths. There are three separate factors involved:
•    The beta-2 reliever covers up the effects of the severe inflammation of the airways. People feel reasonably well, because the reliever is opening up their airways, and don’t realise just how bad their asthma really is. The untreated inflammation in the airways can eventually lead to a very serious, and potentially fatal, asthma attack.
•    The short-acting beta-2 reliever, used regularly, makes the airways more sensitive to exercise, and to allergens such as dust mite or pollen. This means that an asthmatic who is already allergic to these allergens reacts to them at much lower levels in the air.
•    The airways become less and less responsive to the beta-2 reliever itself, so that when a serious attack occurs, requiring hospital treatment, huge doses of beta-2 reliever are needed to open up the airways. These massive doses carry a risk of serious side effects involving the heart.
The details of the New Zealand epidemic still evoke controversy. Was fenoterol itself, which is stronger than other beta-2 relievers, the cause of the deaths? Or was it just that the inhaler delivered a double dose - would any short-acting beta-2 reliever be dangerous at twice the normal dose? Or was it over-use of all beta-2 relievers and lack of preventer drugs?
Some common brand names
Common brand names include:
short-acting beta-2 relievers in inhalers - Aerolin, Airomir, Bricanyl, Ventolin short-acting beta-2 relievers in tablets - Bambec, Bricanyl, Volmax short-acting beta-2 relievers in syrup - Monovent, Ventolin
long-acting beta-2 relievers in inhalers - Bambec, Foradil, Oxis, Serevent
Until this is resolved, safety-conscious asthmatics may want to assume that any of these possibilities could be correct. An ultra-cautious approach would include:
•    Avoiding fenoterol (it is no longer available in Britain, except in the Duovent inhaler, combined with an anti -choli nerg ic drug)
•    Not using double-dose inhalers of any beta-2 reliever (i.e. inhalers that deliver 200mcg/ micrograms per puff)
•    Not routinely taking two puffs of a single-dose inhaler (check with your doctor if you have been told to take two puffs)
•    Using any short-acting beta-2 reliever only I as needed’ – which should be once a day or less according to British guidelines. Note that, with this level of use, there is absolutely no risk from these drugs: it is only regular over-use that is damaging and dangerous.
•    Using a peak-flow meter and ensuring that you are assessed regularly by your doctor
•    Always taking your preventer medication as prescribed.
Since about 1990, the death rate from asthma has been falling, particularly in countries with a policy of reducing use of beta-2 relievers, and increasing inhaled steroids. The death rate in New Zealand is now the lowest it has been for 50 years, and at the same level as in other Western countries.
Unnecessary alarm
While investigating the causes of the New Zealand epidemic, medical researchers discovered that patients inhaling a short-acting beta-2 reliever four times a day had more irritable airways after just two weeks. Their airways were also less responsive to the drug, even after this brief period of use.
Some researchers began to ask if the asthma epidemic itself – the increasing number of cases of asthma – could actually be due to these drugs. Maybe children with mild wheezing, which might have cleared up if left untreated (and which would have gone untreated in the past) were becoming full-blown asthmatics because they were now using beta-2 inhalers?
Many doctors became very concerned about these questions, and a leading medical journal
published an article with the provocative title: ‘Worldwide worsening wheezing – is the cure the cause?’ That was in 1992. Since then, much more research has been done, and it is clear that this particular fear about beta-2 relievers was unfounded.
Unfortunately, there are a few books and other publications around that are spreading unnecessary alarm about these drugs by reporting the debate as it was in 1992. They have taken up that question ‘Is the cure the cause?’, assumed that the answer is ‘yes’, and ignored all the subsequent research, which shows the opposite.
Beta-2 relievers in severe asthma
A few patients with severe asthma remain breathless and wheezy, even though they are inhaling moderate doses of a steroid preventer every day. Increasing the dose of inhaled steroids does not make a huge difference to their symptoms, and it substantially raises the risk of steroid side effects.
Taking a long-acting beta-2 reliever often works wonders for such patients. These relatively new drugs relax the airway muscles, and go on working for 12 hours or more.
There has obviously been concern about long-acting beta-2 relievers having the same sort of insidious side effects as their short-acting colleagues (see p. 153), and so increasing the likelihood of deaths from asthma. However, studies of people taking these drugs suggest that the risks are minimal. Certainly, long-acting drugs taken twice a day are very much safer than short-acting drugs taken four times a day.
Other studies show that the chemical differences of the long-acting drugs, as well as prolonging their effects, also give them a more complex set of actions in the body. For example, they improve the effect of steroids in calming inflammation, and may even have some small anti-inflammatory effect of their own.
Doctors believe that, for patients with troublesome asthma, the benefits of long-acting beta-2 relievers greatly outweigh the risks. But they should only be used in combination with inhaled steroids. Various other options, such as allergen avoidance and the new anti - leukotriene drugs (see p. 159), should probably be investigated as well.
If you are taking long-acting beta-2 relievers, do use them regularly, once every 12 hours – the good effect gradually builds up with consistent use.
Generally speaking, you should not take additional doses in between. These are not intended for use if you have a sudden asthma attack – your doctor will prescribe a short-acting beta-2 reliever for this. This limitation on the use of long-acting beta-2 relievers is certainly appropriate for salmeterol (which was the first of the long-acting beta-2 relievers to be developed) because it is very slow to take effect on the airways. However, one of the newer long-acting beta-2 relievers, called formoterol, begins to work just as quickly as a short-acting beta-2 reliever. Formoterol could, in theory, be used on an ‘as-needed’ basis to combat asthma attacks. You may want to discuss this possibility with your doctor.
Finally, don’t stop taking your preventer drug (e.g. inhaled steroid or cromoglycate), even if you feel a lot better. Long-acting beta-2 relievers are not a substitute for preventers.
Some patients with very severe asthma need to take regular doses of short-acting beta-2 relievers as well as long-acting beta-2 relievers. You should obviously follow the advice of your asthma specialist closely if you are on this kind of drug regime, and not change anything without approval. However, it might be worth discussing other options, such as anti -leukotriene drugs. In addition, do all you can to combat your asthma in other ways – by reducing allergen exposure, avoiding asthma triggers (see p. 39), and employing various other self-help measures (see p. 41).
Immediate side effects of beta-2 relievers
Minor immediate side effects of these drugs include:
•    headache
•    nervousness, trembling, restlessness, anxiety; children may become more excitable, and some are badly behaved or even aggressive.
•    flushing
•    dry mouth
•    muscle cramps.
These side effects – all of which are due to the resemblance of beta-2 relievers to adrenaline – usually wear off relatively quickly. Some long-acting beta-2 relievers may cause nausea and vomiting.
A pounding heart is usually a relatively minor side effect, but it can be more serious, and should be reported to your doctor.
A few asthmatics find that their airways tighten up when these drugs are inhaled, rather than opening. This is called paradoxical bronchoconstriction. If this happens, stop using the inhaler and see your doctor as soon as you can.
Even more rarely, asthmatics can develop allergic reactions to the drugs, or suffer hallucinations or seizures. Obviously you should stop using the inhaler immediately if you experience side effects of this kind, and should see your doctor.
There can be an interaction between beta-2 relievers and other drugs or medical conditions. Should you need a diuretic, tell the doctor or pharmacist that you are also taking a beta-2 reliever, and ask which diuretics are safe. If you have high blood pressure, a heart problem, or a thyroid condition, make sure the doctor remembers this when prescribing beta-2 relievers.
Adrenaline inhalers
Adrenaline inhalers are for use in emergencies. Technically, they are not available in Britain, but they can be imported under special licence, and your doctor may be persuaded to obtain one for you if he or she thinks it might be useful. They are given to people who have asthma and have sometimes had attacks of anaphylaxis (see p. 58), for example in reaction to food, latex or an insect sting. The inhaler provides prompt emergency treatment for the kind of severe asthma attack that you may experience during anaphylaxis.
You should probably be carrying an adrenaline auto-injector as well, as you may need to use both (see p. 98). Those who usually have fairly mild reactions to their allergen can use the inhaler first, to treat symptoms in the mouth, throat and airways. If other symptoms develop, such as faintness or widespread nettle rash,
Asthma alert
If you ever find that your short-acting beta-2 reliever has no effect within ten minutes, or is needed more than once every four hours, this indicates a serious asthma attack and you need urgent medical help (see p. 100).
During a severe asthma attack, while getting to hospital or waiting for a doctor to arrive, up to 30 puffs of a short-acting beta-2 reliever should be taken as an emergency treatment, to get the airways open. There is a risk of death if you don’t use the reliever fully in this situation. (This emergency dose is safe for almost everyone, but there may be risks if you have a heart condition – get detailed advice from your doctor in advance.)
then the adrenaline injector can be used. Those with a history of more severe reactions should start with the adrenaline injector and then use the inhaler if there are still symptoms in the mouth or airways.
Don’t exceed the maximum number of puffs stated on the canister, as the propellant can cause problems. If you have a heart condition, your doctor will advise you about using this kind of treatment safely - adrenaline can affect the heart.
Ephedrine
Ephedrine and orciprenaline (brand name Alupent) belong to the previous generation of reliever drugs. They are chemically very similar to adrenaline and therefore cause a lot of side effects, especially involving the heart.
These drugs are no longer recommended, and will soon be phased out completely. Some older asthmatics may still be using them, just because they have been on them for years and no one has reviewed their treatment.
If you are taking such drugs, ask your doctor about switching to a newer form of reliever - it will be more effective in treating your asthma, as well as having fewer side effects.
Anti -cho linerg ics
These drugs, also known as anti-muscarinics, are relievers. However, they work in a completely different way from the beta-2 relievers. They block the action of the parasympathetic nervous system, a set of nerves that are the biological equivalent of auto-pilot - working without the intervention of conscious thought. The parasympathetic nervous system has many effects on the body, including keeping the airway muscles nicely toned (see box on p. 235). By blocking the parasympathetic, anticholinergics help the airway muscles to relax.
Anti-cholinergics are taken by inhaler, and require 30-90 minutes to achieve their full effects. They should continue working for 3-6 hours.
Some common brand names
Common brand names of anti-cholinergics include: inhalers – Atrovent, Oxivent
nasal spray - Rinatec
For most asthmatics, especially those with a strong allergic component to their asthma, anti-cholinergics are generally less effective than beta-2 relievers. But they are useful to children under one year, who may not respond to beta-2 relievers. They also have a role where asthma is combined with chronic bronchitis -here the anti -choli nerg ics can sometimes be more effective than beta-2 relievers - and they are particularly useful for asthma with a lot of mucus, because blocking the parasympathetic tends to reduce mucus production. For severe asthmatics, anticholinergics may be combined with beta-2 relievers.
Anti -choli nerg ics should be taken only when needed, not regularly several times a day. If used regularly, they can make the airways more sensitive, just as short-acting beta-2 relievers can (see p. 153).
Side effects
Minor side effects of anti-cholinergics may include a dry mouth, blurred vision, constipation, and irritation of the mouth and throat. A few people suffer nausea or difficulty in passing urine.
Serious side effects are rare. Any increase in the stickiness of the sputum coughed up may be a cause for concern, especially in children. If there is an increase in wheezing or coughing, stop taking the drug and see your doctor.
If you already have glaucoma or prostate problems you should be monitored carefully by your doctor, as these conditions can get worse with anti -choli nerg ic drugs.
When anti -choli nerg ics are used in a nebuliser, it is vital that the mask fits well (see p. 163).
Anti-cholinergics for the nose
Another use for anti-cholinergics is in nasal sprays, for the treatment of vasomotor rhinitis, a non-allergic condition that is frequently mistaken for allergic rhinitis (see p. 29). In this disorder, the constant flow of mucus is caused by a malfunction of the parasympathetic nervous system, which is why anti-cholinergics work well.