Apraclonidine dosing

Instill 1 to 2 drops in the affected eye(s) 3 times daily. Because apraclonidine 0.5% will be used with other ocular glaucoma therapies, use an approximate 5-minute interval between instillation of each medication to prevent washout of the previous dose. Not for injection into the eye. 

Pharmacokinetics Topical use of apraclonidine 0.5% leads to systemic absorption. The onset of action is usually within 1 hour and the maximum lOP reduction occurs 3 to 5 hours after application of a single dose. 

The most common nonocular side effect associated with apraclonidine is a sensation of dry mouth or dry nose. These symptoms are dose related. Although the increased polarity of apraclonidine compared with cloni-dine reduces the drug s potential for systemic absorption, cardiovascular, respiratory, and CNS effects can occur with topical application. However, in both normal volunteers and patients with elevated lOP, topical administration appears to cause only minimal effects on resting heart rate, arterial blood pressure, and respiration. 

After topical instillation, brimonidine penetrates into the aqueous humor and produces a dose-dependent reduction in lOP in both normal and glaucomatous eyes. Fluorophotometric studies suggest that brimonidine lowers lOP by a dual mechanism, involving a reduction of aqueous production and an increase in aqueous outflow via the uveoscleral pathway. The initial effect of brimonidine on lOP can be attributed to a decrease in aqueous flow. After 8 days, similar to apraclonidine, the initial effect is attenuated, and uveoscleral flow increases. 

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