TIMOPTIC IN OCUDOSE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TIMOPTIC IN OCUDOSE (TIMOPTIC IN OCUDOSE).
Timolol is a non-selective beta-adrenergic receptor antagonist (beta-1 and beta-2) that reduces intraocular pressure by decreasing aqueous humor production, likely by blocking beta-adrenergic receptors in the ciliary epithelium.
| Metabolism | Primarily metabolized in the liver by CYP2D6; timolol undergoes extensive hepatic first-pass metabolism. |
| Excretion | Renal: approximately 80% as unchanged drug and metabolites; biliary/fecal: minor (less than 10%). |
| Half-life | Terminal elimination half-life is 4-6 hours in adults; prolonged to 8-12 hours in renal impairment. |
| Protein binding | Approximately 60% bound to human plasma proteins, primarily albumin. |
| Volume of Distribution | Vd: 1.3-1.7 L/kg; distributes widely into tissues including aqueous humor. |
| Bioavailability | Ophthalmic: peak plasma concentrations are less than 10% of those after oral administration due to low systemic absorption; oral bioavailability is about 50-75%. |
| Onset of Action | Ophthalmic: reduction in intraocular pressure begins 30-60 minutes after instillation. |
| Duration of Action | Ophthalmic: IOP reduction persists for 12-24 hours; clinical effect lasts up to 24 hours with once-daily dosing. |
| Molecular Weight | 316.42 |
Instill 1 drop of 0.25% or 0.5% solution in the affected eye(s) twice daily.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No specific dose adjustment recommended; use with caution in severe renal impairment (CrCl <30 mL/min) due to potential systemic accumulation. |
| Liver impairment | No specific dose adjustment recommended; use with caution in severe hepatic impairment (Child-Pugh class C) due to reduced metabolism. |
| Pediatric use | Safety and efficacy not established; use not recommended in pediatric patients. |
| Geriatric use | No specific dose adjustment; monitor for systemic effects (e.g., bradycardia, hypotension) due to potential increased sensitivity and reduced drug clearance. |
| 1st trimester | Timolol ophthalmic is generally avoided in first trimester unless benefit outweighs risk. Risk of fetal bradycardia and intrauterine growth restriction due to β-blockade. Use lowest effective dose and monitor fetal heart rate. |
| 2nd trimester | May be used with caution for glaucoma treatment if topical therapy needed. Monitor fetal growth and heart rate due to potential β-blocker effects. |
| 3rd trimester | Use with caution. Risk of neonatal bradycardia, hypotension, and respiratory depression if used near term. Consider switching to alternative agent or discontinuing before delivery. |
Clinical note
Comprehensive clinical and safety monograph for TIMOPTIC IN OCUDOSE (TIMOPTIC IN OCUDOSE).
| Placental transfer | Timolol crosses the placenta. After ophthalmic administration, systemic absorption is low but measurable; however, placental transfer can still occur. Fetal plasma concentrations may reach levels similar to maternal. Risk of fetal β-blockade. |
| Breastfeeding |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Bronchial asthmaSevere chronic obstructive pulmonary disease (COPD)Sinus bradycardiaSecond- or third-degree atrioventricular blockCardiogenic shockOvert cardiac failureHypersensitivity to timolol or any component of the formulation
| Precautions | Exacerbation of asthma and other pulmonary diseases due to bronchospasm, Cardiovascular effects including bradycardia, heart failure, and heart block, Masking of symptoms of hypoglycemia in diabetic patients, Abrupt withdrawal may exacerbate angina or thyroid storm in patients with hyperthyroidism, Anaphylactic reactions: Patients may be unresponsive to usual doses of epinephrine |
| Food/Dietary | No significant food interactions. |
Loading safety data…
| Timolol is excreted into breast milk in small amounts. Ophthalmic use results in minimal systemic absorption. However, if the infant is premature or has hepatic/renal impairment, risk of β-blockade effects (bradycardia, hypotension) exists. Monitor infant for signs of β-blockade. Use lowest effective dose and consider pump and discard for 2-3 hours after administration. |
| Lactation Rating | L3 – Moderately Safe (limited data, use with caution) |
| Teratogenic Risk | Insufficient human data; animal studies show no teratogenicity at clinically relevant doses. Ophthalmic use results in minimal systemic absorption. No specific fetal risks identified for any trimester. |
| Fetal Monitoring | No specific monitoring required for ophthalmic use. In pregnant women with glaucoma, monitor intraocular pressure and fetal growth if systemic absorption suspected. |
| Fertility Effects | No known adverse effects on fertility from ophthalmic timolol. |
| Clinical Pearls | Timoptic (timolol maleate) in OCUDOSE is a non-selective beta-blocker for ophthalmic use. It can cause systemic beta-blockade; monitor for bradycardia, bronchospasm, and mask hypoglycemia in diabetics. Use with caution in patients with COPD, asthma, sinus bradycardia, heart block, or heart failure. Use punctal occlusion after instillation to reduce systemic absorption. OCUDOSE unit-dose preservative-free formulation is preferred for patients with ocular surface sensitivity. Contraindicated in reactive airway disease. |
| Patient Advice | Wash hands before use. Do not touch the dropper tip to any surface. · Remove contact lenses before instillation and wait 15 minutes before reinserting. · Apply punctal occlusion (press finger at inner corner of eye) for 1-2 minutes after each drop. · Do not use if solution is discolored or contains particles. · Store at room temperature; discard single-use vial after opening. · May cause blurred vision; avoid driving until vision clears. · Report shortness of breath, slow heart rate, dizziness, or fainting immediately. · Do not discontinue abruptly without consulting prescriber. |