A patient came to the casualty with acute bronchial asthma after treatment for glaucoma. The probable drug may be –
First, I remember that glaucoma treatments include beta-blockers, prostaglandin analogs, alpha agonists, and others. Beta-blockers are systemic and can cause bronchoconstriction, which is bad for asthma. So maybe a beta-blocker like timolol? But wait, timolol is a non-selective beta-blocker, so it blocks beta-2 receptors in the lungs, leading to bronchospasm. That makes sense for causing asthma symptoms.
Wait, the options aren't given, but the correct answer is probably a beta-blocker. Let me think of common glaucoma drugs. Betaxolol is another beta-blocker. But the key here is that non-selective beta-blockers are more likely to cause bronchospasm. So if the patient was on a non-selective beta-blocker, that could trigger asthma.
Other glaucoma drugs like pilocarpine (muscarinic agonist) might cause bronchoconstriction too, but that's less common. Prostaglandin analogs like latanoprost don't typically cause asthma.
So the probable drug here is a non-selective beta-blocker. The correct answer would be something like timolol. The other options would be incorrect because they either don't affect beta-2 receptors or are used for other purposes. The clinical pearl is to remember that beta-blockers can exacerbate asthma, so they should be avoided in asthmatic patients.
**Core Concept**
This question tests knowledge of drug-induced bronchospasm, particularly drugs used in glaucoma treatment that may precipitate asthma attacks. Beta-adrenergic antagonists are a high-yield category to remember for this context.
**Why the Correct Answer is Right**
Non-selective beta-blockers (e.g., **timolol**) are first-line treatments for glaucoma due to their ability to reduce intraocular pressure by decreasing aqueous humor production. However, they inhibit **beta-2 adrenergic receptors** in bronchial smooth muscle, causing bronchoconstriction. In patients with asthma, this can trigger acute exacerbations by increasing airway resistance and worsening airflow obstruction.
**Why Each Wrong Option is Incorrect**
**Option A:** *If pilocarpine was listed*—a cholinergic agonist used in glaucoma, it causes pupillary constriction but bronchodilation via muscarinic receptor blockade.
**Option B:** *If latanoprost was listed*—a prostaglandin analog that lowers intraocular pressure without pulmonary effects.
**Option C:** *If epinephrine was listed*—a sympathomimetic used in glaucoma, it may cause mild bronchodilation.
**Option D:** *If acetazolamide was listed*—a carbonic anhydrase inhibitor that reduces aqueous humor production but does not directly affect bronchial smooth muscle.
**Clinical Pearl / High-Yield Fact**
**Never prescribe non-selective beta-blockers to patients with asthma.** Even topical formulations (e.g., timolol eye drops) can cause systemic absorption and bronchospasm. Use beta-1