Drugs and the respiratory system

Abstract

The respiratory system serves as an important interface for gas exchange. It is vital to maintain the health of the airways to ensure a free flow of gases. Certain diseases that affect the airways and the gas exchange site are best treated with drugs delivered directly to the target sites via the inhalational route. This will not only result in immediate action but will keep the required drug dosages to the minimum and thus reduce their systemic side-effects. The non-inhalational mode is an alternative option when the passage to the gas exchange interface is too severely obstructed or if the drugs can only be given via the systemic route. There are two major classes of bronchodilators delivered via the inhalational mode in acute care, i.e., the beta 2 agonists and the anticholinergics. The two differ in both the onset of action as well as the duration of action. A combination of drugs from different classes is often employed in the acute situation to achieve the best bronchodilatory effect. Drug delivery for patients with poor inhalational technique can be assisted by means of a spacer or a nebulizer.