timolol maleate

Drug Name

Generic Name : timolol maleate

Brand Name: Apo-Timol (CAN), Apo-Timop (CAN), Betimol, Blocadren, Gen-Timolol (CAN), Novo-Timol (CAN), Nu-Timolol (CAN), Timoptic, Timoptic-XE

Classification: Beta-adrenergic blocker, Antihypertensive, Antiglaucoma drug

Pregnancy Category C 

Dosage & Route

Available forms : Tablets—5, 10, 20 mg; ophthalmic solution, gel—0.25%, 0.5%

ADULTS

Oral

  • Hypertension: Initially, 10 mg bid. Increase dosage at 1-wk intervals to a maximum of 60 mg/day divided into two doses, as needed. Usual maintenance dose is 20–40 mg/day given in two divided doses.
  • Prevention of reinfarction in MI (long-term prophylaxis in patients who survived the acute phase): 10 mg bid PO within 1–4 wk of infarction.
  • Migraine: 10 mg PO bid; during maintenance, the 20 mg/day may be given as a single dose. May be increased to a maximum of 30 mg/day in divided doses or decreased to 10 mg/day. Discontinue if satisfactory response is not obtained after 6–8 wk.

Ophthalmic

  • Initially, 1 drop of 0.25% solution bid into the affected eye or eyes. Adjust dosage on basis of response to 1 drop of 0.5% solution bid or 1 drop of 0.25% solution daily. When replacing other agents, make change gradually and individualize dosage. One drop in the affected eye each morning (Istalol).
PEDIATRIC PATIENTS
  • Safety and efficacy not established.
Therapeutic actions
  • Timolol is a non-selective β-adrenergic receptor blocker which does not have significant intrinsic sympathomimetic, direct myocardial depressant or local anesthetic activity. It decreases intraocular pressure by reducing aqueous humor formation or increase outflow.
Indications
  • Hypertension, used alone or in combination with other antihypertensives, especially thiazide-type diuretics
  • Prevention of reinfarction in MI patients who are hemodynamically stable
  • Prophylaxis of migraine
  • Ophthalmic solution: Reduction of IOP in chronic open-angle glaucoma, some patients with secondary glaucoma, aphakic patients with glaucoma ocular hypertension
Adverse effects
  • Fatigue, coldness of extremities, paresthesia, GI symptoms, skin rash, alopecia, dry mouth, bradycardia. Ophthalmic use: Blurred vision, burning, stinging, ocular irritation, decreased corneal sensitivity, visual disturbances, diplopia, ptosis, cystoid macular edema, pseudopemphigoid, choroidal detachment following filtration surgery. Systemic absorption with systemic effects may occur.
  • Potentially Fatal: Heart failure, heart block, bronchospasm, respiratory failure.
Contraindications
  • Present or history of bronchial asthma, COPD, present or history of bronchospastic disease, sinus bradycardia, 2nd and 3rd degree heart block, overt heart failure, cardiogenic shock. Pregnancy.
Nursing considerations
Assessment
  • History: Sinus bradycardia, second- or third-degree heart block, cardiogenic shock, CHF, asthma, COPD, pregnancy, lactation, diabetes or thyrotoxicosis
  • Physical: Weight, skin condition, neurologic status, P, BP, ECG, respiratory status, renal and thyroid function, blood and urine glucose
Interventions
  • WARNING: Do not discontinue drug abruptly after long-term therapy (hypersensitivity to catecholamines may have developed, causing exacerbation of angina, MI, and ventricular arrhythmias). Taper drug gradually over 2 wk with monitoring.
  • Consult with surgeon about withdrawal if patient is to undergo surgery (withdrawal is controversial).
Teaching points
  • Do not stop taking this drug unless instructed to do so by your health care provider.
  • Avoid driving or dangerous activities if dizziness or shaking occurs.
  • If using ophthalmic form, administer eye drops properly to minimize systemic absorption.
  • Report difficulty breathing, night cough, swelling of extremities, slow pulse, confusion, depression, rash, fever, sore throat.