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Timolol in aqueous humour after topical administration. A pilot study
Acta Ophthalmologica
|August 1, 1985
Summary
A single drop of timolol ophthalmic solution achieved high concentrations in the aqueous humor, but with significant patient variability. No timolol was detected in plasma, suggesting localized ocular effects.
Area of Science:
- Ophthalmology
- Pharmacokinetics
Background:
- Timolol is a common beta-blocker used in ophthalmic solutions to treat glaucoma.
- Understanding its intraocular penetration and systemic absorption is crucial for patient safety and efficacy.
Purpose of the Study:
- To measure the concentration of timolol in the aqueous humor after a single drop of timolol ophthalmic solution.
- To assess systemic absorption by measuring plasma concentrations.
Main Methods:
- 19 patients received one drop of timolol ophthalmic solution.
- Aqueous humor and plasma samples were collected and analyzed for timolol concentration.
Main Results:
- Mean aqueous humor timolol concentration was 626 ng/ml, with a wide range (0-2080 ng/ml).
- No detectable levels of timolol were found in plasma (detection limit >= 1 ng/ml).
Conclusions:
- Timolol ophthalmic solution leads to substantial concentrations within the aqueous humor.
- Significant inter-individual variability in aqueous humor concentration exists.
- Systemic absorption of timolol from a single drop appears minimal.
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