Asthma Inhalers

The asthma inhalers are hand held devices which helps in the intake of drugs for the treatment of asthma at anytime and anywhere i.e. they are portable device.  Asthma inhalers help in delivering the medicines directly to the respiratory airways unlike the tablets and liquid form of asthma drugs. So when inhalers are used only less dose of medicines required for asthma treatment than the tablet and liquid form. Since the inhalers deliver drugs directly to the airways, only less amount of drug enters rest of the body and thus the side effects will be minimal or even absent.

The invention of asthma inhalers had changed the way of treatment in asthmatics. It is easy to use for both adults and children. Apart from using the inhalers the patient should also frequently monitor the lung function using the peek flow meter and also avoid contact with the asthma triggering factors. The asthma triggering factors will be specific for each patient. Some of the most common triggering factors are dust, smoke, odour, certain food items, exhausting exercise etc.

Types of Asthma Inhalers

The most important types of asthma inhalers are:

Metered Dose Inhaler (MDI)

Metered dose inhaler is a device which contains a pressurized canister which fits into the boot shaped mouth piece. The medicines are present within the canister. Most of the metered dose inhaler works when the pressurized canister is pushed to the boot which helps in the release of a fine mist containing desired dose of medicine. CFC (Chloro Flouro Carbon) was used as the gas propellant in earlier day, but now it is no longer used as it causes damage to the ozone layer when released out. There are two types of metered dose inhalers. They are:

  1. The Standard Metered Dose Inhaler: The standard metered dose inhaler contains an inactive pressurized gas which helps in propelling a specific dose of drug in each puff. Pressing on the top portion of inhaler helps in the release of drug. The patient should breath fully at the time when the canister is pressed i.e. the patient should be able to coordinate it very well. The standard metered dose inhaler is easy to use and convenient to carry.
  2. Breath-activated Metered Dose Inhaler: In breath-activated inhaler there is no need to press the canister to release the medicine unlike the standard metered dose inhaler. Here the drug is delivered directly when the patient inhales through the mouth piece. Thus they require less coordination than the standard metered dose inhaler. Their size is bigger than the standard metered dose inhaler.
  3. Metered Dose Inhaler with Spacer

This type of inhaler has a spacer attached to it. The spacer will have contact with both the inhaler and the patient’s mouth. They act as a reservoir and store the medicine once the inhaler is pressed. A valve present at the end of the spacer helps keeping the drug safe within it and will be released only when the patient inhales through it. The valve gets closed when the patient exhales. As the spacer can store the medicine it gives the patient time to inhale slowly and thereby decreasing the amount of drug which gets deposited on the back of throat. Thus the spacer helps in delivering medicines directly to the lungs. If a patients requires more than one puff to achieve the required dose, the second puff should not be taken just after the first one instead the inhaler should be shaken well and then the second puff taken. The patient should inhale and exhale few times before each puff and should also try to hold the breath for few seconds after each breath. Some metered dose inhalers will have spacers already attached to it others may have a separate spacer. The metered dose inhaler with spacer will sometimes have a face mask attached to it which is designed especially for children.

Dry Powder Inhaler

Unlike the other two inhalers the dry powder inhaler does not have a gas propellant to push the medicine out of the inhaler. Instead the drug is released through a deep fast breath. Here each dose of drug will be present in powder form. This type of inhalers is not suitable for small children as they may not be able to take a deep fast breath properly. The major disadvantage of dry powder inhaler is that accidental breathing out may blow away the medicine and the medicine usually gets deposited at the back of throat or tongue. If there is high humidity the dry powder medicine may clump. Different types of dry powder inhalers are dry powder tube inhaler, powder disk inhaler and single dose dry powder disk inhaler.

Some patients use Nebuliser instead of inhalers. Nebuliser is a devise which is used by patients who finds difficult in using an inhaler, usually infants and young children. Nebulizer helps in delivering the medicine in mist form which can be inhaled easily through the face mask attached to it.

Points to be noted before selecting an inhaler

Certain type of asthma inhalers may seem to be more effective for some patients than other types. So the right type should be used selected which helps in delivering the medicine in required amount. Certain points to be considered before choosing the inhaler are as follows: 

  1. Age of the patient: Patients in different age group will feel certain type of inhaler convenient to them. Elderly people will find metered dose inhalers difficult to use. Similarly children under five years of age feel difficult to use dry powder inhalers. Children under the age of twelve feel convenient in using metered dose inhalers with spacers attached to it.
  2. Size of the inhaler: Some inhalers are smaller in size than others which are easy and convenient to handle. Example for small sized inhaler is the metered dose inhaler
  3. Side effect: Inhalers usually deliver the drugs to the back of the throat which may lead to Oral Thrush. This mostly occurs when a high dose of medicine is to be delivered. To overcome this problem, a spacer should be attached to the inhaler. Thus patients who needs larger dose of medicine can use inhaler with spacer attached to it.

Medicines Used in Inhalers And Different Brands

The medicines used in asthma inhalers may be of preventive type or reliever type.

Reliever Inhalers: Reliever inhalers are used only “as required” when the symptoms are severe. They are also known as Bronchodilator Inhalers since they help in dilation or relaxation of the constricted smooth muscles of the bronchi. In patients with the history of exercise induced asthma, bronchodilators should be taken prior to exercise. Reliever inhalers are of two types The Short Acting Reliever Inhalers and Long Acting Reliever Inhalers. The bronchodilator drugs used are:

  1. Short acting beta-agonists- It includes Xopenex, Alupent, Maxair and Albuterol (Proventil HFA, Ventolin HFA, AccuNeb)
  2. Long acting beta agonists- It includes Advair, Symbicort, Serevent(Salmeterol), Foradil(Formoterol)
  3. Combivent and DuoNeb Inhalers- It contains Ipratorium and Albuterol

Preventer Inhalers:

Preventer inhalers are taken daily to prevent the asthma symptoms from developing. They contains anti-inflammatory drugs mostly steroids which helps in reducing the inflammation in breathing tubes and also in reducing mucous secretion. Preventer inhalers will not give an immediate effect and will take about 6 – 12 days for its action. The drugs used in preventer inhalers are:

  1. Corticosteroids like Quvar, Simbicort, Pulmicort, Aerobid, Advair and Flovent.
  2. Mast cell stabilisers like Intal and Tilade.

The recent studies have shown that one person dies every seven hours from asthma, but surprisingly about 90% of these cases are preventable with proper medication and control.