Medical Guides

Inhalation Therapy

The major advantage of delivering drugs directly into the airways via inhalation is that high concentrations can be delivered more effectively to the airways and side effects are avoided or minimised. Some of the drugs that are effective in asthma can only be used via inhalation because they are not absorbed when given orally (e.g. anticholinergics and cromones).
Metered Dose Inhalers (MDI):

A metered dose inhaler is a device to deliver asthma medicines in aerosol form. The MDI contains a pressurised inactive gas that propels the medicine. A dose is released by pressing the top of the inhaler. It takes only 5 to 10 minutes for the inhaled medicine to have an effect compared to liquid or tablet forms, which require about 1 to 3 hours. To use a Metered Dose Inhaler, follow the instructions provided along with the inhaler.

Common errors in its use include: not shaking the inhaler before using it; inhaling too jerkily or at the wrong time; not holding the breath long enough after an inhaler puff.

Spacer: A spacer is a device to deliver the medication more efficiently while using an inhaler. It is especially useful for people who have difficulty in using a metered dose inhaler correctly.

Nebulisers:

A nebuliser is a device which uses compressed air to convert liquid medicine into a fine mist. This device uses a continuous air pump attached to a nebulising chamber in which liquid bronchodilator and/or steroid is poured. An oxygen mask is connected to the chamber. A nebuliser delivers a continuous medicated vapour to the lungs and is very effective for moderate to severe asthmatics for whom inhalers alone are not enough.

Dry Powder Inhalers: In these types of inhalers medicine is in a powder form that has to be sucked in. Various dry powder inhaler devices are available. Each has a different method of providing the medicine.

To get the powder into the lungs, forceful inhalation is required. Most adults and older children can do this. However, dry powder inhalers are not suitable for children under six as they often cannot breathe in hard enough to suck in all the powder.