Timolol (Moisol) Eye Drops Dosage for Glaucoma and Ocular Hypertension
Start with one drop of timolol 0.25% in the affected eye(s) twice daily, and if the response is inadequate after 4 weeks, increase to timolol 0.5% twice daily. 1
Standard Dosing Protocol
- Initial dose: One drop of timolol 0.25% solution in the affected eye(s) twice daily 1
- Dose escalation: If clinical response is inadequate, increase to one drop of timolol 0.5% solution twice daily 1
- Evaluation timing: Assess intraocular pressure (IOP) after approximately 4 weeks of treatment, as the pressure-lowering response may require several weeks to stabilize 1
Dosing Optimization
- Once-daily option: If IOP is maintained at satisfactory levels on twice-daily dosing, the schedule may be changed to one drop once daily 1
- Timing consideration: Because of diurnal IOP variations, the adequacy of once-daily dosing is best determined by measuring IOP at different times during the day 1
- Maximum dose: Dosages above one drop of timolol 0.5% twice daily generally have not been shown to produce further IOP reduction 1
When Monotherapy Is Insufficient
- Combination therapy: If IOP remains unsatisfactory on maximum timolol dosing, add concomitant therapy with other IOP-lowering agents 1
- Avoid dual beta-blockers: Do not use two topical beta-adrenergic blocking agents simultaneously 1
- Alternative first-line agents: Prostaglandin analogs are the most frequently prescribed initial therapy for glaucoma because they are most efficacious, well-tolerated, and require only once-daily dosing 2, 3
Treatment Goals and Monitoring
- Target IOP: Aim for approximately 20% lower than baseline mean IOP measurements 2, 4
- Regular assessment: Evaluate IOP at each visit and adjust target pressure based on optic nerve structure and visual field stability 2
- Long-term efficacy: Timolol 0.5% twice daily produces mean IOP reductions of 5.6-6.6 mm Hg at trough and similar reductions at peak 5
Administration Technique
- Reduce systemic absorption: Educate patients about eyelid closure or nasolacrimal duct occlusion when applying drops to minimize systemic side effects 2
- Multiple drop regimens: Wait at least 5 minutes between different eye drop medications 2
- Adherence support: Link eye-drop administration to daily activities and provide repeated instruction on proper technique 2
Important Caveats
- Cardiovascular effects: Timolol can cause decreases in heart rate (mean reduction of 4-5 bpm), though blood pressure changes are typically not significant 5
- Pregnancy category: Timolol is FDA Pregnancy Category C; beta-blockers tend to be used during pregnancy due to long-term experience, but careful risk-benefit assessment is required 2
- Adherence challenges: Nearly 45% of patients take fewer than 75% of prescribed doses even with instruction; simplified regimens and counseling improve adherence 2