The following adverse reactions have been reported in clinical trials of up to 3 years of patient experience with betaxolol ophthalmic suspension.
Ocular: Betaxolol suspension has been well tolerated. Discomfort of short duration may be experienced by some patients upon instillation and occasional tearing has been reported. Instances of blurred vision on instillation, decreased corneal sensitivity, erythema, itching sensation, corneal punctate staining, keratitis, anisocoria and photophobia have been reported.
Systemic: Systemic reactions following topical administration of betaxolol suspension have been reported rarely (e.g., CNS: insomnia and depressive neurosis).
No data are available on overdosage of humans. However, anticipated symptoms include symptomatic bradycardia, hypotension, bronchospasm, acute cardiac failure and heart block (second or third degree).
A 10 mL container of 0.25% betaxolol ophthalmic suspension would contain 25 mg of betaxolol. Betaxolol at 40 mg twice daily is reported to be an effective and safe systemic dosage for hypertension. Thus, an individual would ingest an amount of betaxolol from one container which is less than the maximum daily oral dose of betaxolol.
Since the oral LD50 in animals ranged from 350 to 1 050 mg/kg, a 10 kg child would only receive 2.5 mg/kg if the child ingested 10 mL of 0.25% betaxolol ophthalmic suspension. An acute toxic response is thus extremely remote.
The usual dose is 1 drop of betaxolol ophthalmic suspension in the affected eye(s) twice daily. In some patients, the intraocular pressure lowering response may require a few weeks to stabilize. Clinical follow-up should include a determination of the intraocular pressure during the first month of treatment. Thereafter, intraocular pressures should be determined on an individual basis at the judgment of the physician.
When a patient is transferred from a single antiglaucoma agent, continue the agent already used and add 1 drop of betaxolol ophthalmic suspension in the affected eye(s) twice a day. On the following day, discontinue the previous antiglaucoma agent completely and continue with betaxolol ophthalmic suspension.
Because of diurnal variations of intraocular pressure in individual patients, satisfactory response to twice a day therapy is best determined by measuring intraocular pressure at different times during the day. Intraocular pressure of less than 22 mm Hg may not be optimal for control of glaucoma in each patient; therefore, therapy should be individualized.
If the intraocular pressure of the patient is not adequately controlled on this regimen, concomitant therapy with pilocarpine, other miotics, epinephrine or systemically administered carbonic anhydrase inhibitors can be instituted.
When a patient is transferred from several concomitantly administered antiglaucoma agents, individualization is required. Adjustment should involve one agent at a time made at intervals of not less than 1 week. A recommended approach is to continue the agents being used and add 1 drop of betaxolol ophthalmic suspension in the affected eye(s) twice a day. On the following day, discontinue one of the other antiglaucoma agents. The remaining antiglaucoma agents may be decreased or discontinued according to the patient's response to treatment. The physician may be able to discontinue some or all of the other antiglaucoma agents.
Special Instructions: Patients should be instructed to avoid contamination of the dropper tip.
The Betoptic S suspension must be well shaken before use.
Each mL of sterile, isotonic, aqueous suspension contains: betaxolol 0.25% (0.28% betaxolol HCl) with benzalkonium chloride (as preservative), mannitol, poly (styrene- divinyl benzene) sulfonic acid, carbomer 934P, edetate disodium, hydrochloric acid and/or sodium hydroxide (to adjust pH) and purified water. Drop-Tainer dispensers of 5 and 10 mL. Store at room temperature (15 to 30°C).
