Timolol Maleate 5 mg Tablet, 100-count — NDC 16571-223-01 (Billing 16571-0223-01)

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If cardiac failure persists, therapy with timolol maleate should be withdrawn.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If cardiac failure continues, despite adequate digitalization and diuretic therapy, timolol should be withdrawn. Exacerbation of Ischemic Heart Disease Following Abrupt Withdrawal Hypersensitivity to catecholamines has been observed in patients withdrawn from beta-blocker therapy; exacerbation of angina and, in some cases, myocardial infarction have occurred after abrupt discontinuation of such therapy. When discontinuing chronically administered timolol maleate, particularly in patients with ischemic heart disease, the dosage should be gradually reduced over a period of one to two weeks and the patient should be carefully monitored.

If angina markedly worsens or acute coronary insufficiency develops, timolol maleate administration should be reinstituted promptly, at least temporarily, and other measures appropriate for the management of unstable angina should be taken. Patients should be warned against interruption or discontinuation of therapy without the physician's advice. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue timolol maleate therapy abruptly even in patients treated only for hypertension.

Obstructive Pulmonary Disease 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 MALEATE' IS CONTRAINDICATED, see CONTRAINDICATIONS), SHOULD IN GENERAL NOT RECEIVE BETA-BLOCKERS, INCLUDING 'TIMOLOL'. However, if timolol is necessary in such patients, then the drug should be administered with caution since it may block bronchodilation produced by endogenous and exogenous catecholamine stimulation of beta 2 receptors.

Major Surgery The necessity or desirability of withdrawal of beta-blocking therapy prior to major surgery is controversial. Beta-adrenergic receptor blockade impairs the ability of the heart to respond to beta-adrenergically mediated reflex stimuli. This may augment the risk of general anesthesia in surgical procedures.

Some patients receiving beta-adrenergic receptor blocking agents have been subject to protracted severe hypotension during anesthesia. Difficulty in restarting and maintaining the heartbeat has also been reported. For these reasons, in patients undergoing elective surgery, some authorities recommend gradual withdrawal of beta-adrenergic receptor blocking agents.

If necessary during surgery, the effects of beta-adrenergic blocking agents may be reversed by sufficient doses of such agonists as isoproterenol, dopamine, dobutamine or norepinephrine (see OVERDOSAGE). Diabetes Mellitus Timolol should be administered with caution in patients subject to spontaneous hypoglycemia or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic receptor blocking agents may mask the signs and symptoms of acute hypoglycemia.

Thyrotoxicosis Beta-adrenergi… [Excerpted — this section continues on DailyMed.]

ADVERSE REACTIONS Timolol maleate tablets are usually well tolerated in properly selected patients. Most adverse effects have been mild and transient. In a multi-center (12 week) clinical trial comparing timolol maleate and placebo in hypertensive patients, the following adverse reactions were reported spontaneously and considered to be causally related to timolol maleate: Timolol Maleate (n=176) % Placebo (n=168) % BODY AS A WHOLE fatigue/tiredness 3.4 0.6 headache 1.7 1.8 chest pain 0.6 0 asthenia 0.6 0 CARDIOVASCULAR bradycardia 9.1 0 arrhythmia 1.1 0.6 syncope 0.6 0 edema 0.6

1.2DIGESTIVE dyspepsia 0.6 0.6 nausea 0.6 0 SKIN pruritus 1.1 0 NERVOUS SYSTEM dizziness 2.3 1.2 vertigo 0.6 0 paresthesia 0.6 0 PSYCHIATRIC decreased libido 0.6 0 RESPIRATORY dyspnea 1.7 0.6 bronchial spasm 0.6 0 rales 0.6 0 SPECIAL SENSES eye irritation 1.1 0.6 tinnitus 0.6 0 These data are representative of the incidence of adverse effects that may be observed in properly selected patients treated with timolol maleate, i.e., excluding patients with bronchospastic disease, congestive heart failure or other contraindications to beta-blocker therapy.

In patients with migraine the incidence of bradycardia was 5 percent. In a coronary artery disease population studied in the Norwegian multi-center trial (see CLINICAL PHARMACOLOGY), the frequency of the principal adverse reactions and the frequency with which these resulted in discontinuation of therapy in the timolol and placebo groups were: Adverse Reaction* Withdrawal † Timolol (n=945) % Placebo (n=939) % Timolol (n=945) % Placebo (n=939) % Asthenia or Fatigue 5 1 <1 <1 Heart Rate < 40 beats/minute 5 <1 4 <1 Cardiac Failure-Nonfatal 8 7 3 2 Hypotension 3 2 3 1 Pulmonary Edema-Nonfatal 2 <1 <1 <1 Claudication 3 3 1 <1 AV Block 2nd or 3rd Degree <1 <1 <1 <1 Sinoatrial Block <1 <1 <1 <1 Cold Hands and Feet 8 <1 <1 0 Nausea or Digestive Disorders 8 6 1 <1 Dizziness 6 4 1 0 Bronchial Obstruction 2 <1 1 <1 *When an adverse reaction recurred in a patient, it is listed only once. † Only principal reason for withdrawal in each patient is listed.

These adverse reactions can also occur in patients treated for hypertension. The following additional adverse effects have been reported in clinical experience with the drug: Body as a Whole: anaphylaxis, extremity pain, decreased exercise tolerance, weight loss, fever; Cardiovascular: cardiac arrest, cardiac failure, cerebral vascular accident, worsening of angina pectoris, worsening of arterial insufficiency, Raynaud's phenomenon, palpitations, vasodilatation; Digestive: gastrointestinal pain, hepatomegaly, vomiting, diarrhea, dyspepsia; Hematologic: nonthrombocytopenic purpura; Endocrine: hyperglycemia, hypoglycemia; Skin: rash, skin irritation, increased pigmentation, sweating, alopecia; Musculoskeletal: arthralgia; Nervous System: local weakness, increase in signs and symptoms of myasthenia gravis; Psychiatric: depression, nightmares, somnolence, insomnia, nervousness, diminished concentration, hallucinations; Respiratory: cough; Special Senses: visual disturbances, diplopia, ptosis, dry eyes; Urogenital: impotence, urination difficulties.

There have been reports of retroperitoneal fibrosis in patients receiving timolol maleate and in patients receiving other beta-adrenergic blocking agents. A causal relationship between this condition and therapy with beta-adrenergic blocking agents has not been established. Potential Adverse Effects In addition, a variety of adverse effects not observed in clinical trials with timolol maleate, but reported with other beta-adrenergic blocking agents, should be considered potential adverse effects of timolol.

Nervous System: Reversible mental depression progressing to catatonia; an acute reversible syndrome characterized by disorientation for time and place, short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics; Cardiovascular: Intensification of AV block (see CONT… [Excerpted — this section continues on DailyMed.]

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. Drug Interactions Catecholamine-Depleting Drugs Close observation of the patient is recommended when timolol is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may produce vertigo, syncope, or postural hypotension. Non-Steroidal Anti-Inflammatory Drugs Blunting of the antihypertensive effect of beta-adrenoceptor blocking agents by non-steroidal anti-inflammatory drugs has been reported.

When using these agents concomitantly, patients should be observed carefully to confirm that the desired therapeutic effect has been obtained. Calcium Antagonists Literature reports suggest that oral calcium antagonists may be used in combination with beta-adrenergic blocking agents when heart function is normal, but should be avoided in patients with impaired cardiac function. Hypotension, AV conduction disturbances, and left ventricular failure have been reported in some patients receiving beta-adrenergic blocking agents when an oral calcium antagonist was added to the treatment regimen.

Hypotension was more likely to occur if the calcium antagonist were a dihydropyridine derivative, e.g., nifedipine, while left ventricular failure and AV conduction disturbances were more likely to occur with either verapamil or diltiazem. Intravenous calcium antagonists should be used with caution in patients receiving beta-adrenergic blocking agents. Digitalis and Either Diltiazem or Verapamil The concomitant use of beta-adrenergic blocking agents with digitalis and either diltiazem or verapamil may have additive effects in prolonging AV conduction time.

Quinidine Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with quinidine and timolol, possibly because quinidine inhibits the metabolism of timolol via the P-450 enzyme, CYP2D6. Clonidine Beta-adrenergic blocking agents may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the two drugs are coadministered, the beta-adrenergic blocking agent should be withdrawn several days before the gradual withdrawal of clonidine.

If replacing clonidine by beta-blocker therapy, the introduction of beta-adrenergic blocking agents should be delayed for several days after clonidine administration has stopped. Risk from Anaphylactic Reaction While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated accidental, diagnostic, or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions.

Carcinogenesis, Mutagenes… [Excerpted — this section continues on DailyMed.]