|Levobunolol Other Names||Levobunolol, Levobunololum|
|Therapeutic Class||Drugs for miotics and glaucoma|
|Last Updated:||September 19, 2023 at 7:00 am|
Levolol is a nonselective β-adrenergic blocking agent. It causes the reduction of intraocular pressure by decreasing the production of aqueous humour.
Levolol is an ophthalmic beta-blocker, equally effective at β(1)- and β(2)-receptor sites. Levolol reduces both elevated and normal IOP in patients with or without glaucoma. In patients with elevated IOP, levobunolol reduces mean IOP by approximately 25-40% from baseline. As the drug is a nonselective &beta-adrenergic blocking agent, it can produce both systemic pulmonary and cardiovascular effects following topical application to the eye. These effects include adverse pulmonary effects (eg. bronchoconstriction, increased airway resistance), and a decrease in blood pressure and heart rate.
How Levolol works
Levolol's mechanism of action in reducing IOP is not clearly defined, but is believed to be due to a reduction of the production of aqueous humor via blockage of endogenous catecholamine-stimulated increases in cyclic adenosine monophosphate (AMP) concentrations within the ciliary processes.
The recommended starting dose is one to two drops of Levobunolo ophthalmic solution 0.5% in the affected eye(s) once a day. Typical dosing with Levolol 0.25% is one to two drops twice daily. In patients with more severe or uncontrolled glaucoma, Levobunolo 0.5% can be administered b.i.d. As with any new medication, careful monitoring of patients is advised. Dosages above one drop of Levolol 0.5% b.i.d. are not generally more effective. If the patient's IOP is not at a satisfactory level on this regimen, concomitant therapy with dipivefrin and/or epinephrine, and/or pilocarpine and other miotics, and/or systemically administered carbonic anhydrase inhibitors, such as acetazolamide, can be instituted. Patients should not typically use two or more topical ophthalmic beta-adrenergic blocking agents simultaneously.
Common side effects are ocular stinging, burning, blepharoconjunctivitis, blepharitis, decreased visual acuity, band keratopathy, erythema, iridocyclitis, conjunctivitis and itching sensation; bradycardia, CVA, syncope, arrhythmia, heart block, hypotension, cerebral ischaemia, bronchospasm. Rarely, reduced corneal sensitivity and tearing.
Bradycardia, hypotension, bronchospasm, and acute cardiac failure, LD50=700 mg/kg (orally in rat).
Patients with diminished pulmonary function, nonallergic bronchospasm, inadequate cardiac function, DM, myasthenia gravis. May mask signs and symptoms of hypoglycaemia and hyperthyroidism. Avoid abrupt withdrawal as it may precipitate thyroid storm. Pregnancy and lactation.
Additive hypotensive effect with catecholamine-depleting drug (e.g. reserpine), Ca channel blockers, β-adrenergic blockers, digitalis glycosides, antiarrhythmics, guanethidine, parasympathomimetics. Mydriasis may occur when used with epinephrine.
Food InteractionNo interactions found.
Pregnancy & Breastfeeding use
There are no adequate and well-controlled studies in pregnant women. Levolol ophthalmic solution should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
It is not known whether this drug is excreted in human milk. Systemic beta-blockers and topical timolol maleate are known to be excreted in human milk. Caution should be exercised when Levolol is administered to a nursing woman.
Levolol ophthalmic solution is contraindicated in those individuals with bronchial asthma, or with a history of bronchial asthma, or severe chronic obstructive pulmonary disease; sinus bradycardia; second and third degree atrioventricular block; overt cardiac failure; cardiogenic shock; or hypersensitivity to any component of these products.
Pediatric Use: Safety and effectiveness in pediatric patients have not been established.
Geriatric Use: No overall differences in safety or effectiveness have been observed between elderly and younger patients.
No data are available regarding overdosage in humans. Should accidental ocular overdosage occur, flush eye(s) with water or normal saline. If accidentally ingested, efforts to decrease further absorption may be appropriate (gastric lavage). The most common signs and symptoms to be expected with overdosage with administration of a systemic beta-adrenergic blocking agent are symptomatic bradycardia, hypotension, bronchospasm, and acute cardiac failure. Should these symptoms occur, discontinue Levolol therapy and initiate appropriate supportive therapy. The following supportive measures should be considered:
Symptomatic bradycardia: Use atropine sulfate intravenously in a dosage of 0.25 mg to 2 mg to induce vagal blockade. If bradycardia persists, intravenous isoproterenol hydrochloride should be administered cautiously. In refractory cases the use of a transvenous cardiac pacemaker should be considered.
Hypotension: Use sympathomimetic pressor drug therapy, such as dopamine, dobutamine or levarterenol. In refractory cases the use of glucagon hydrochloride may be useful.
Bronchospasm: Use isoproterenol hydrochloride. Additional therapy with aminophylline may be considered.
Acute cardiac failure: Conventional therapy with digitalis, diuretics and oxygen should be instituted immediately. In refractory cases the use of intravenous aminophylline is suggested. This may be followed, if necessary, by glucagon hydrochloride which may be useful.
Heart block (second or third degree): Use isoproterenol hydrochloride or a transvenous cardiac pacemaker.