Timolol Started in a Patient With Poorly Controlled Asthma
Mr. Delgado, 68, arrives as a new patient for glaucoma evaluation. While you take his history before the physician is free, he mentions that an outside optometrist started latanoprost at bedtime and timolol 0.5% twice daily two weeks ago. He has "bad asthma," has used his albuterol inhaler far more than usual since starting the drops, and had an emergency department visit for wheezing last month. He says the drops "make me cough a little," so he has been skipping the morning dose. Seated pulse is 54 bpm and regular; blood pressure is 138/82. He reports occasional dizziness when standing. The physician is running 25 minutes behind, and the technician before you already instilled the scheduled morning timolol "to stay on time." Mr. Delgado asks you whether he should just stop the drops himself.
1. Which findings change what you do next, and what actions do you take before the physician sees him?
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The history of asthma with increased rescue-inhaler use, new cough, pulse of 54 bpm, and dizziness on standing all cluster around systemic beta-adrenergic blockade from timolol. Timolol is a nonselective beta-blocker; even a small fraction absorbed through the nasolacrimal mucosa can cause bronchospasm, bradycardia, hypotension, heart block, fatigue, and depression. The temporal link to starting the drop makes this an adverse drug effect, not a coincidence to chart and forget.
Actions, in order:
- Do not instill another timolol. The morning dose is already on board; a second dose adds risk without benefit.
- Seat him, recheck pulse and blood pressure, ask specifically about wheeze, chest tightness, and shortness of breath, and make sure his albuterol inhaler is within reach.
- Notify the physician now, not at the end of clinic, using whatever urgent-call pathway exists. This is a same-visit safety issue.
- Do not tell him to stop the drop himself. That is the physician's decision; you can say the doctor will review it immediately.
- Document the symptoms, vitals, time of the already-given dose, and time of physician notification.
A cardio-selective agent such as betaxolol carries less bronchospastic risk but is not risk-free, so the physician may switch classes entirely.
2. The physician discontinues timolol and prescribes brimonidine 0.2% twice daily. Explain the change to Mr. Delgado and teach punctal occlusion.
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Explain in plain terms: timolol is a beta-blocker that can reach the lungs and heart after absorption, which is why his breathing worsened and his pulse slowed. Brimonidine is a different class, an alpha-2 adrenergic agonist, that lowers eye pressure by reducing aqueous production and increasing uveoscleral outflow without tightening the airways the way a beta-blocker can. It is not free of side effects: dry mouth, fatigue or drowsiness, and a fairly common allergic reaction (red, itchy, irritated eyes and lids) that can appear after weeks to months of use. Tell him to call if his eyes become red and itchy rather than simply stopping, and to avoid driving until he knows whether it makes him drowsy. Brimonidine is generally avoided in young children, so mention any grandchildren only as a storage caution: keep bottles out of reach.
Punctal occlusion technique: one drop in the eye, close gently, press the index finger over the nasolacrimal sac at the inner corner for 1 to 2 minutes, then blot excess without rinsing. This reduces drainage into the nose and throat, cutting systemic absorption and side effects while improving how much drug stays in the eye. Have him demonstrate it back to you.
3. What do you document, and what instructions and follow-up do you give about the skipped doses, dizziness, and stopping the old bottle?
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Documentation should be objective and time-stamped: the asthma history and inhaler escalation, cough, pulse 54, blood pressure 138/82, orthostatic dizziness, the fact that the morning timolol had already been instilled, the exact time the physician was notified, the response, and the education given. Note that he was told not to stop or alter drops on his own. If your clinic uses an incident or adverse-drug-reaction report, complete it.
Instructions: discard or set aside the timolol bottle as directed by the physician, not by you; do not double the brimonidine dose to "catch up" after a missed one; if a dose is missed, take it when remembered unless the next dose is close, then resume the regular schedule. Continue the latanoprost at bedtime. Report wheezing, chest tightness, pulse below 50, fainting, or worsening dizziness immediately. Keep an updated medication and allergy list, including over-the-counter inhalers.
The dizziness deserves a follow-up blood pressure check, including standing pressures, because it may reflect systemic beta-blockade or an unrelated cause. Confirm the follow-up interval for intraocular pressure and medication tolerance, and give written instructions plus a phone number, since patients often forget verbal teaching when they are anxious.