| TIMOLOL MALEATE
Betimol, Blocadren, Istalol, Timoptic, Timoptic XE
Classifications: beta-adrenergic antagonist; eye preparation; miotic; Therapeutic: miotic
Pregnancy Category: C
5 mg, 10 mg, 20 mg tablets; 0.25%, 0.5% ophthalmic solution or gel
Nonselective beta-adrenergic antagonist. Demonstrates antihypertensive, antiarrhythmic, and antianginal properties, and
suppresses plasma renin activity. When applied topically, lowers elevated and normal intraocular pressure (IOP) by reducing
formation of aqueous humor and possibly by increasing outflow.
Topically, lowers elevated and normal intraocular pressure (IOP). Orally, therapeutically useful for mild hypertension and
Topically (ophthalmic solution) to reduce elevated IOP in chronic, open-angle glaucoma, aphakic glaucoma, secondary glaucoma,
and ocular hypertension. May be used alone or in conjunction with epinephrine, pilocarpine, or a carbonic anhydrase inhibitor
such as acetazolamide. Oral preparation is used as monotherapy or in combination with a thiazide diuretic to prevent reinfarction
after MI and to treat mild hypertension.
Prophylactic management of stable, uncomplicated angina pectoris and migraine headaches.
Bronchospasm; severe COPD; bronchial asthma; heart failure; pregnancy (category C), abrupt discontinuation, acute bronchospasm,
AV block, bradycardia, cardiogenic shock, acute pulmonary edema, compromised left ventricular dysfunction, Raynaud's disease.
Safety in children is not established.
Bronchitis, patients subject to bronchospasm, asthma; sinus bradycardia, greater than first-degree heart block, heart failure;
renal impairment; hepatic disease; vasospastic angina, peripheral vascular disease; pheochromocytoma; thyrotoxicosis, hyperthyroidism;
right ventricular failure secondary to pulmonary hypertension, COPD; stroke, cerebrovascular disease; depression; older
adults; psoriasis; myasthenia gravis; concomitant use with adrenergic augmenting drugs (e.g., MAO inhibitors).
Route & Dosage
See Appendix A-1.
Adult: PO 10 mg b.i.d., may increase to 60 mg/d in 2 divided doses
Adult: PO 1545 mg in 3 divided doses
- Give with fluid of patient's choice; tablet may be crushed.
- Make dosage increases for hypertension at weekly intervals.
Adverse Effects (≥1%) CNS: Fatigue
, lethargy, weakness, somnolence, anxiety, headache, dizziness, confusion, psychic dissociation, depression
Palpitation, bradycardia, hypotension, syncope, AV conduction disturbances, CHF, aggravation of peripheral vascular insufficiency. Special Senses: Eye irritation
, blepharitis, keratitis, superficial punctate keratopathy. GI:
Anorexia, dyspepsia, nausea. Skin:
Rash, urticaria. Respiratory:
Difficulty in breathing, bronchospasm. Body as a Whole:
Fever. Metabolic: Hypoglycemia
InteractionsDrug: antihypertensive agents
, diuretics, selective serotonin reuptake inhibitors
potentiate hypotensive effects; nsaid
s may antagonize hypotensive effects.
90% absorbed from GI tract; 50% reaches systemic circulation; some systemic absorption from topical application. Peak:
12 h PO; 15 h topical. Distribution:
Distributed into breast milk. Metabolism:
80% metabolized in liver to inactive metabolites. Elimination:
Assessment & Drug Effects
- Check pulse before administering timolol, topical or oral. If there are extremes (rate or rhythm), withhold medication and
call the physician.
- Assess pulse rate and BP at regular intervals and more aften in patients with severe heart disease.
- Note: Some patients develop tolerance during long-term therapy.
Patient & Family Education
- Be aware that drug may cause slight reduction in resting heart rate. Learn how to assess pulse rate and report significant
changes. Consult physician for parameters.
- Do not stop drug abruptly; angina may be exacerbated. Dosage is reduced over a period of 12 wk.
- Report difficulty in breathing promptly to physician. Drug withdrawal may be indicated.