Which medication is known to potentially cause respiratory side effects?

Timolol is a non-selective beta-blocker that can have respiratory side effects, particularly in individuals with pre-existing respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD). This medication works by blocking beta-adrenergic receptors, which can lead to bronchoconstriction in susceptible patients.

In contrast, the other medications listed—aspirin, ibuprofen, and acetaminophen—are primarily known for their analgesic or anti-inflammatory properties and do not typically exhibit respiratory-related side effects in the same way. While aspirin can provoke asthma in some individuals who are sensitive to it (known as aspirin-exacerbated respiratory disease), it does not directly cause respiratory side effects in the general population the way timolol can. Therefore, timolol is distinctly recognized for its potential impact on respiratory function, particularly in those at risk.