Several common medication categories can trigger bronchospasm, worsen breathing, or cause full asthma attacks. The most important ones to know about are beta-blockers, aspirin and related pain relievers, and certain eye drops. Some of these are obvious prescriptions, while others are over-the-counter drugs you might take without a second thought.
Beta-Blockers: The Biggest Risk
Beta-blockers are prescribed for high blood pressure, heart failure, and irregular heartbeats. They work by blocking receptors in the heart that respond to adrenaline. The problem is that those same receptors also exist in your airway muscles, and blocking them causes the airways to tighten.
Non-selective beta-blockers are the most dangerous for people with asthma because they block receptors in both the heart and the lungs. Propranolol, sotalol, nadolol, and timolol all fall into this category. In studies comparing how well rescue inhalers work after taking these drugs, people who took a non-selective beta-blocker saw their lung function decline by about 1%, while those on placebo saw the expected 23% improvement. That’s not just a reduced benefit; the medication actively made breathing worse.
Cardioselective beta-blockers like metoprolol and atenolol primarily target heart receptors and are generally considered safer. A Cochrane review found they did not cause substantial short-term breathing problems in people with mild-to-moderate asthma. That said, they’re not risk-free. In dose-dependent fashion, selective beta-blockers caused an average 7% drop in lung function and reduced rescue inhaler effectiveness by about 10%. Roughly 1 in 8 patients experienced a significant decline in lung function, and 1 in 33 had noticeably worse asthma symptoms. If your asthma is unstable or poorly controlled, even cardioselective beta-blockers should be avoided.
Beta-Blocker Eye Drops
This one catches people off guard. Timolol and levobunolol eye drops, commonly prescribed for glaucoma, are non-selective beta-blockers. When you put them in your eye, the drug gets absorbed through the tear drainage system into your bloodstream without being filtered by the liver first. Researchers have compared this absorption to receiving the drug intravenously.
A meta-analysis found that non-selective beta-blocker eye drops caused an average 10.9% drop in lung function in people with asthma, and one in three patients experienced a clinically significant decline of 20% or more. If you have asthma and need glaucoma treatment, selective alternatives exist, though even those caused a 6.3% average drop in patients who were sensitive to the non-selective versions. Make sure your eye doctor knows about your asthma before starting any glaucoma drops.
Aspirin and NSAIDs
About 9% of all adults with asthma are sensitive to aspirin and other common pain relievers like ibuprofen and naproxen. That number jumps to 30% among people who have both asthma and nasal polyps. This condition, called aspirin-exacerbated respiratory disease (AERD), involves a triad of asthma, chronic sinus disease with nasal polyps, and reactions to drugs that block an enzyme involved in inflammation.
Reactions typically include sudden worsening of asthma symptoms, nasal congestion, and sometimes facial flushing. They can range from mild to severe. If you have AERD and haven’t undergone aspirin desensitization (a supervised medical procedure), you should avoid all standard NSAIDs. That includes over-the-counter options like ibuprofen, naproxen, and aspirin itself.
For pain relief, acetaminophen (Tylenol) is generally tolerated at standard doses by most people with aspirin-sensitive asthma, though very high doses can occasionally cause reactions in a small subset. Your doctor may also consider COX-2 selective pain relievers, which target a different enzyme pathway and typically don’t trigger the same response.
Cholinergic Medications
Drugs that stimulate the parasympathetic nervous system can tighten airway muscles directly. Bethanechol, used for urinary retention and bladder problems, carries an FDA-listed contraindication for both active and latent bronchial asthma. It works by activating receptors that increase smooth muscle contraction throughout the body, including in the airways. Pilocarpine, sometimes prescribed for dry mouth or used in eye drops, acts on the same receptor system and poses similar risks.
Sulfite-Containing Medications
Sulfites are preservatives added to many injectable and liquid medications to prevent them from breaking down. They’re found in some local anesthetics, injectable corticosteroids, adrenaline (epinephrine), and certain antibiotics. Older bronchodilator solutions like isoproterenol and isoetharine contained sulfite concentrations high enough to cause airway tightening in most people with asthma, even those without a known sulfite sensitivity.
There’s an uncomfortable irony here: all commercially available epinephrine preparations contain sulfite preservatives. Since epinephrine is the primary treatment for severe allergic reactions, this creates a difficult situation for the rare patient who is both sulfite-sensitive and experiencing anaphylaxis. In practice, the life-saving benefit of epinephrine far outweighs the sulfite risk, but it’s worth knowing about if you’ve had confirmed sulfite reactions.
Anesthesia Agents
If you’re heading into surgery, your anesthesia team should know about your asthma. Certain muscle relaxants used during general anesthesia can trigger histamine release, which narrows the airways. Atracurium and mivacurium are the most notable, with documented cases of non-allergic reactions that mimic anaphylaxis. Suxamethonium has been specifically linked to bronchospasm and elevated airway pressure during allergic reactions. Rocuronium may also carry a relatively higher anaphylaxis risk compared to similar drugs. Your anesthesiologist will choose agents based on your specific history, but flagging your asthma ahead of time helps them plan appropriately.
Why Overusing Rescue Inhalers Is Also a Problem
This isn’t a medication to avoid entirely, but it’s worth understanding. The 2024 GINA guidelines emphasize that relying on a short-acting rescue inhaler alone, without a daily inhaled corticosteroid, is no longer considered safe management. Using a rescue inhaler regularly for even one to two weeks can lead to your airways becoming less responsive to it over time. The receptors that the medication targets start to downregulate, meaning the drug works less well exactly when you need it most. You can also develop rebound airway sensitivity, where your breathing actually becomes more reactive between doses. Current guidelines recommend that every adult and adolescent with asthma use an inhaled corticosteroid-containing treatment as their foundation, rather than reaching for a rescue inhaler as a standalone fix.