Professional and Linguistic Assessments Board (PLAB) Practice Exam

What class of drug does aminophylline belong to?

1. Anti-inflammatory

2. Anticholinergic

3. Bronchodilator

4. Leukotriene modifier

The correct answer is: Bronchodilator

Aminophylline is classified as a bronchodilator, which plays a significant role in the treatment of respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). It acts primarily through the relaxation of bronchial smooth muscle, leading to an expanded airway and improved airflow, which is essential for patients experiencing bronchospasm. The mechanism of action involves the inhibition of phosphodiesterase, an enzyme that breaks down cyclic AMP (cAMP). By preventing the breakdown of cAMP, aminophylline increases intracellular levels, which results in bronchial dilation and reduced airway resistance. This class of medication is crucial in acute management situations as well as in chronic care for patients with obstructive airway diseases. The other classifications of drugs mentioned, such as anti-inflammatories, anticholinergics, and leukotriene modifiers, serve different purposes in respiratory therapy. Anti-inflammatories address inflammation rather than bronchial constriction directly, anticholinergics block the action of the neurotransmitter acetylcholine on the bronchi, and leukotriene modifiers inhibit specific inflammatory mediators. While they are all important in managing respiratory conditions, they do not have the same primary action as bronchodilators like aminophylline.