Timolol Maleate 0.5% Eye prep
Indications
Timolol Maleate 0.5% Eye prep is used for:
Open-angle glaucoma, Ocular hypertension
Adult Dose
Ophthalmic
Open-angle glaucoma; Ocular hypertension
Adult: Initial: The usual starting dose is one drop in the affected eye(s) twice a day. Reduce to 1 drop/day if controlled.
Child Dose
Safety & efficacy not established
Renal Dose
Administration
Contra Indications
Hypersensitivity to any component of this product; bronchial asthma; history of bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second or third degree atrioventricular block; overt cardiac failure; cardiogenic shock
Precautions
Observe patients receiving topical timolol and a systemic ß-adrenergic blocking agent concomitantly for potential additive effects on IOP and/or systemic effects of ß-adrenergic blockade
Severe respiratory reactions and cardiac reactions, including death due to bronchospasm in patients with asthma, and rarely death in association with cardiac failure, reported following systemic or ophthalmic administration of timolol maleate
Patients with chronic obstructive pulmonary disease (e.g., chronic bronchitis, emphysema) of mild or moderate severity, bronchospastic disease, or a history of bronchospastic disease (other than bronchial asthma or a history of bronchial asthma, in which timolol is contraindicated) should, in general, not receive beta-blockers
Some authorities recommend gradual withdrawal of beta-adrenergic receptor blocking agents in patients undergoing elective surgery; if necessary during surgery, effects of beta-adrenergic blocking agents may be reversed by sufficient doses of adrenergic agonists
Beta-adrenergic blocking agents should be administered with caution in patients subject to spontaneous hypoglycemia or diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents; beta-adrenergic receptor blocking agents may mask signs and symptoms of acute hypoglycemia
Beta-adrenergic blocking agents may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism; patients suspected of developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta-adrenergic blocking agents that might precipitate thyroid storm
Because of potential effects of beta-adrenergic blocking agents on blood pressure and pulse, these agents should be used with caution in patients with cerebrovascular insufficiency; if signs or symptoms suggesting reduced cerebral blood flow develop following initiation of therapy, alternative therapy should be considered
Pregnancy-Lactation
Pregnancy Category: C
Lactation: Secreted in breast milk; Mfr advises against breast feeding (AAP Committee states compatible with breast feeding)
Interactions
Concomitant admin w/ reserpine may increase hypotension and bradycardia. Additive effects w/ other antihypertensives (e.g. hydralazine, methyldopa). Increased beta-adrenergic blockade (e.g. decreased heart rate) w/ quinidine. Rebound HTN due to abrupt withdrawal of clonidine. Hypotensive effect may be antagonised by NSAIDs (e.g. indomethacin, ibuprofen).
Adverse Effects
Side effects of Timolol Maleate 0.5% Eye prep :
>10%
Burning or stinging (38%)
>1%
Blurred vision (4-10%), Cataract (4-10%), Conjunctivitis (4-10%), Decreased visual acuity (4-10%), Headache (4-10%), Hypertension (4-10%), Infection (4-10%), Itching (4-10%)
Frequency Not Defined
Ocular irritation, Blepharitis, Keratitis, Ocular pain, Discharge (e.g., crusting), Foreign body sensation, Dry eyes, Eyelid erythema, Blepharoptosis, Decreased corneal sensitivity, Diplopia, Cystoid macular edema, Pseudopemphigoid, Choroidal detachment following filtration surgery, Epiphora, Photophobia, Conjunctival injection, Corneal fluorescein staining, Retinal vascular disorder, Ptosis
Potentially Fatal: Heart failure, intensification of heart block, bronchospasm, respiratory failure.
Mechanism of Action
Exact mechanism of ocular hypotensive effect is unclear, but it is thought to be related to reduction of aqueous humour formation. beta-blockade also causes lowering of BP.