levobunolol hydrochloride
AKBeta, Betagan

Available forms
Available by prescription only
Ophthalmic solution: 0.25%, 0.5%

Indications and dosages
 Chronic open-angle glaucoma and ocular hypertension. Adults: Instill 1 to 2 drops (0.5% solution) daily or 1 to 2 drops (0.25% solution) b.i.d. in eye.

Pharmacodynamics
Antiglaucoma action: Levobunolol is a nonselective beta blocker that reduces intraocular pressure. Exact mechanisms are unknown, but the drug appears to reduce formation of aqueous humor.

Pharmacokinetics
Absorption: Systemic absorption is undetermined but may occur.
Distribution: Unknown.
Metabolism: Unknown.
Excretion: Unknown.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug and those with bronchial asthma, history of bronchial asthma or severe COPD, sinus bradycardia, second- or third-degree AV block, cardiac failure, and cardiogenic shock. Use cautiously in patients with chronic bronchitis, emphysema, diabetes mellitus, hyperthyroidism, or myasthenia gravis.

Interactions
Drug-drug. Carbonic anhydrase inhibitors, epinephrine, pilocarpine: Increases reduction in intraocular pressure. Use together cautiously.
Catecholamine-depleting drugs, reserpine: Enhances hypotensive and bradycardiac effects of these drugs. Monitor patient carefully.
Oral beta blockers: Increases systemic effects. Monitor patient carefully.

Adverse reactions
CNS: headache, depression, insomnia.
CV: slight reduction in resting heart rate.
EENT: transient eye stinging and burning, tearing, erythema, itching, keratitis, corneal punctate staining, photophobia; decreased corneal sensitivity (with long-term use).
GI: nausea.
Skin: urticaria.
Other: evidence of beta blockade and systemic absorption (hypotension, bradycardia, syncope, asthmatic attacks in patients with history of asthma, heart failure).

Effects on lab test results
None reported.

Overdose and treatment
Overdose is extremely rare with ophthalmic use. However, usual symptoms include bradycardia, hypotension, bronchospasm, heart block, and cardiac failure.
 After accidental ingestion, emesis is most effective if started within 30 minutes, providing patient isn’t obtunded, comatose, or having seizures. Follow with activated charcoal. Treat bradycardia, conduction defects, and hypotension with I.V. fluids, glucagon, atropine, or isoproterenol. Treat bronchoconstriction with I.V. aminophylline, and treat seizures with I.V. diazepam.

Special considerations
 ALERT Drug contains sodium metabisulfite, which may precipitate an allergic reaction in susceptible people.
• Levobunolol is faster acting than timolol.
• Because levobunolol has little or no effect on pupil size, don’t use drug alone in patients with angle-closure glaucoma; use with a miotic.
• Cardiac output is reduced in both healthy patients and those with heart disease. Drug may decrease heart rate and blood pressure and produces beta blockade in bronchi and bronchioles. No effect on pupil size or accommodation has been noted. Monitor patient for these effects.
• In some patients, a few weeks’ treatment may be required to stabilize pressure-lowering response; determine intraocular pressure after 4 weeks of treatment.
• Store at 59° to 86° F (15° to 30° C) in light-resistant container.
Geriatric patients
• Use drug cautiously in elderly patients with cardiac or pulmonary disease, whose symptoms may worsen depending on extent of systemic absorption.

Patient education
• Warn patient not to touch dropper to eye or surrounding tissue.
• Show patient how to instill drug. Teach him to press lacrimal sac lightly for 1 minute after drug administration, to decrease chance of systemic absorption.
• Remind patient not to blink more than usual or to close eyes tightly during treatment.
• Tell patient to report severe reaction, although transient stinging and discomfort are common.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use