TIMOPTIC-XE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TIMOPTIC-XE (TIMOPTIC-XE).
Timolol is a nonselective beta-adrenergic receptor antagonist that blocks beta-1 and beta-2 adrenergic receptors. In the eye, it reduces aqueous humor production by inhibiting beta-2 receptors in the ciliary epithelium, thereby lowering intraocular pressure.
| Metabolism | Timolol is metabolized in the liver primarily by CYP2D6 to inactive metabolites. It undergoes first-pass metabolism with systemic bioavailability of about 25-50% after ocular administration. |
| Excretion | Renal: 20% unchanged; remainder as metabolites via urine. Minor biliary/fecal elimination. |
| Half-life | Plasma: 4-6 hours; prolonged in renal impairment. Systemic half-life after ocular dosing: 4-5 hours. |
| Protein binding | ~60% bound to plasma proteins (primarily albumin). |
| Volume of Distribution | 1.3-1.7 L/kg; distributes widely into tissues including eye. |
| Bioavailability | Ocular: systemic absorption ~20% via nasolacrimal duct; oral: ~50% (not used). |
| Onset of Action | Ocular: 0.5-1 hour (IOP reduction). |
| Duration of Action | Ocular: up to 24 hours (IOP lowering); maximal effect at 4-8 hours postdose. |
| Molecular Weight | 316.42 |
Instill one drop of 0.25% or 0.5% solution in the affected eye(s) once daily in the morning.
| Dosage form | SOLUTION, GEL FORMING/DROPS |
| Renal impairment | No dose adjustment required for renal impairment; however, systemic absorption may be increased in severe renal impairment (CrCl <30 mL/min) due to decreased clearance of timolol. Use with caution in such patients. |
| Liver impairment | No specific dose adjustment recommended; caution in severe hepatic impairment due to potential for decreased metabolism. Monitor for systemic effects. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established. Use is not recommended in children <2 years; for ages 2-17 years, initiate with 0.25% solution once daily, may increase to 0.5% if adequate response not achieved. Use beta-blocker with caution and monitor for adverse effects. |
| Geriatric use | Start with 0.25% solution once daily. Lower doses may be effective due to increased systemic absorption and higher risk of adverse effects (e.g., bradycardia, hypotension). Monitor intraocular pressure and systemic side effects closely. |
| 1st trimester | Crosses placenta. Avoid use due to risk of fetal bradycardia and growth restriction. |
| 2nd trimester | Crosses placenta. Avoid use due to risk of fetal bradycardia and growth restriction. |
| 3rd trimester | Crosses placenta. Avoid use due to risk of fetal bradycardia and growth restriction. |
Clinical note
Comprehensive clinical and safety monograph for TIMOPTIC-XE (TIMOPTIC-XE).
| Placental transfer | Crosses placenta; measurable concentrations in fetal serum. |
| Breastfeeding | Timolol is excreted into breast milk; potential for infant bradycardia and hypoglycemia. Use with caution, monitor infant. |
| Lactation Rating |
■ FDA Black Box Warning
No FDA black box warning specific to TIMOPTIC-XE; however, beta blockers have a boxed warning for abrupt cessation in patients with coronary artery disease causing exacerbation of angina and myocardial infarction.
| Serious Effects |
Bronchial asthmaSevere COPDSinus bradycardiaSecond- or third-degree AV blockOvert cardiac failureCardiogenic shock
| Precautions | May cause bronchospasm in patients with asthma or COPD; use with caution., Can cause cardiac depression, bradycardia, and heart failure in susceptible patients., May mask signs of hypoglycemia in diabetic patients., May mask signs of hyperthyroidism., Abrupt withdrawal may exacerbate angina or precipitate myocardial infarction in patients with coronary artery disease., Anaphylactic reactions may be more severe in patients on beta blockers., May cause muscle weakness in myasthenia gravis., Use with caution in patients with history of severe anaphylactic reactions to allergens. |
| Food/Dietary | No specific food interactions are known with timolol ophthalmic solution. Systemic absorption is minimal, but if significant systemic effects occur, avoid excessive caffeine intake as it may counteract effects. No dietary restrictions are required. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Timolol (Timoptic-XE) is a non-selective beta-blocker. In animal studies, timolol was not teratogenic in rats or rabbits at doses up to 50 mg/kg/day (approximately 6000 times the human ophthalmic dose). There are no adequate and well-controlled studies in pregnant women. Beta-blockers, including timolol, may cause fetal bradycardia, growth restriction, and hypoglycemia when administered during the second and third trimesters. The risk of adverse effects is lower with ophthalmic administration due to minimal systemic absorption. |
| Fetal Monitoring | Monitor maternal heart rate and blood pressure for signs of systemic beta-blockade. Monitor fetal heart rate and growth during second and third trimesters. Assess newborn for bradycardia, hypoglycemia, and respiratory depression at delivery. |
| Fertility Effects | No human data on fertility effects. Animal studies (rats) showed no adverse effects on fertility at oral doses up to 50 mg/kg/day (6000 times ophthalmic dose). |
| Clinical Pearls | Timoptic-XE (timolol maleate ophthalmic solution) is a non-selective beta-blocker indicated for reducing intraocular pressure in open-angle glaucoma or ocular hypertension. The XE formulation is a gel-forming solution that increases corneal contact time, allowing once-daily dosing. Systemic absorption can occur; monitor for bradycardia, bronchospasm, and masking of hypoglycemia symptoms in diabetic patients. Use with caution in patients with COPD, asthma, sinus bradycardia, or heart block. Instruct patients to invert the bottle and shake once before use to ensure proper consistency. Tear film break-up time may be prolonged. |
| Patient Advice | Use exactly as prescribed, once daily in the morning. · Before each use, invert the bottle and shake once to mix the solution. · Tilt head back, pull down lower eyelid, and instill one drop into the affected eye(s). · Close eye gently for 1-2 minutes after instillation to minimize systemic absorption. · Do not touch the dropper tip to your eye or any surface to avoid contamination. · Wait at least 10 minutes between using Timoptic-XE and other eye medications. · May cause temporary blurred vision; avoid driving until vision clears. · Contact lenses should be removed before application and may be reinserted after 15 minutes. · Report symptoms like slow heartbeat, difficulty breathing, or swelling of the eyes or eyelids. · Do not stop using without consulting your doctor; withdrawal may increase eye pressure. |