Lower respiratory tract disorders, which include pulmonary disorders like asthma and chronic obstructive pulmonary disease (COPD), are prevalent. This chapter discusses the pharmacology of some of the important classes of drugs used to treat these conditions. Bronchodilators relax smooth muscles and expand airways. Beta-2 agonists and anticholinergics are the two most commonly used bronchodilators used for this purpose. They are available in both short-acting and long-acting formulations. Short-acting (e.g. albuterol) are used as required for sudden episodes of breathlessness, while long-acting may be added if symptoms are not controlled or progress. Bronchodilators help to improve a patient’s overall quality of life through improved lung function, a decrease in symptoms, and improved exercise capacity. Corticosteroids, leukotriene modifiers, mast cell stabilizers, and Immunoglobulin E (IgE) blockers are classes of anti-inflammatory medications that have been shown to be effective treatments in controlling asthma symptoms and attacks. Research and experience have shown that a combination of these medications may be required. This can particularly be true for patients with intermediate and severe symptoms where a single medication has been inadequate in controlling/preventing recurrent symptoms.