Product Description.:
M 715
tablet , green , scored , oblong oblong
Timolol maleate is a nonselective beta-adrenergic receptor blocking agent. The chemical name for timolol maleate is (S)-1-[(1,1-dimethylethyl)amino]-3-[[4-(4-morpholinyl)-1,2,5-thiadiazol-3-yl]oxy]-2-propanol (Z)-2-butenedioate (1:1) salt.
Timolol maleate has a molecular weight of 432.50. It is a white, odorless, crystalline powder which is soluble in water, methanol, and alcohol.
Timolol maleate is supplied as tablets containing 5 mg, 10 mg and 20 mg timolol maleate for oral administration. Inactive ingredients are: colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, microcrystalline cellulose, pregelatinized starch, sodium lauryl sulfate, FD&C Blue #2 aluminum lake, and D&C Yellow #10 aluminum lake.
INDICATIONS AND USAGE
Hypertension
Timolol maleate tablets are indicated for the treatment of hypertension. They may be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.
Myocardial Infarction
Timolol is indicated in patients who have survived the acute phase of myocardial infarction, and are clinically stable, to reduce cardiovascular mortality and the risk of reinfarction.
Migraine
Timolol is indicated for the prophylaxis of migraine headache.
CONTRAINDICATIONS
Timolol maleate is contraindicated in patients with bronchial asthma or with a history of bronchial asthma, or severe chronic obstructive pulmonary disease (see WARNINGS) sinus bradycardia second- and third-degree atrioventricular block overt cardiac failure (see WARNINGS) cardiogenic shock hypersensitivity to this product.
WARNINGS
Cardiac Failure
Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition by beta-adrenergic receptor blockade may precipitate more severe failure. Although beta-blockers should be avoided in overt congestive heart failure, they can be used, if necessary, with caution in patients with a history of failure who are well compensated, usually with digitalis and diuretics. Both digitalis and timolol maleate slow AV conduction. If cardiac failure persists, therapy with timolol maleate should be withdrawn.
In Patients Without a History of Cardiac Failure
Continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of cardiac failure, patients receiving timolol should be digitalized and/or be given a diuretic, and the response observed closely. If cardiac failure continues, despite adequate digitalization and diuretic therapy, timolol should be withdrawn.
PRECAUTIONS
General
Impaired Hepatic or Renal Function
Since timolol is partially metabolized in the liver and excreted mainly by the kidneys, dosage reductions may be necessary when hepatic and/or renal insufficiency is present.
Dosing in the Presence of Marked Renal Failure
Although the pharmacokinetics of timolol are not greatly altered by renal impairment, marked hypotensive responses have been seen in patients with marked renal impairment undergoing dialysis after 20 mg doses. Dosing in such patients should therefore be especially cautious.
Muscle Weakness
Beta-adrenergic blockade has been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g., diplopia, ptosis, and generalized weakness). Timolol has been reported rarely to increase muscle weakness in some patients with myasthenia gravis or myasthenic symptoms.
Cerebrovascular Insufficiency
Because of potential effects of beta-adrenergic blocking agents relative to 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 are observed, consideration should be given to discontinuing these agents.
