Pindolol

INDICATIONS AND USAGE Pindolol tablets are indicated in the management of hypertension. It may be used alone or concomitantly with other antihypertensive agents, particularly with a thiazide-type diuretic.

DOSAGE AND ADMINISTRATION The dosage of pindolol tablets should be individualized. The recommended initial dose of pindolol tablets is 5 mg b.i.d. alone or in combination with other antihypertensive agents. An antihypertensive response usually occurs within the first week of treatment. Maximal response, however, may take as long as or occasionally longer than 2 weeks. If a satisfactory reduction in blood pressure does not occur within 3 to 4 weeks, the dose may be adjusted in increments of 10 mg/day at these intervals up to a maximum of 60 mg/day.

CONTRAINDICATIONS Pindolol tablets are contraindicated in: 1) bronchial asthma; 2) overt cardiac failure; 3) cardiogenic shock; 4) second and third degree heart block; 5) severe bradycardia. (See WARNINGS .)

WARNINGS Cardiac Failure Sympathetic stimulation may be a vital component supporting circulatory function in patients with congestive heart failure, and its inhibition by beta-blockade may precipitate more severe failure. Although beta-blockers should be avoided in overt congestive heart failure, if necessary, pindolol tablets can be used with caution in patients with a history of failure who are well-compensated, usually with digitalis and diuretics. Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase risk of bradycardia. Beta-adrenergic blocking agents do not abolish the inotropic action of digitalis on heart muscle. In Patients Without A History of Cardiac Failure In patients with latent cardiac insufficiency, 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 impending cardiac failure, patients should be fully digitalized and/or be given a diuretic, and the response observed closely. If cardiac failure continues, despite adequate digitalization and diuretic, pindolol tablets therapy should be withdrawn (gradually, if possible). 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of Ischemic Heart Disease Following Abrupt Withdrawal Hypersensitivity to catecholamines has been observed in patients withdrawn from beta-blocker therapy; exacerbation of angina and, in some cases, myocardial infarction have occurred after abrupt discontinuation of such therapy.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 pindolol tablets, particularly in patients with ischemic heart disease, the dosage should be gradually reduced over a period of 1 to 2 weeks and the patient should be carefully monitored. If angina markedly worsens or acute coronary insufficiency develops, pindolol tablets 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 pindolol tablets therapy abruptly even in patients treated only for hypertension. Nonallergic Bronchospasm (e.g., chronic bronchitis, emphysema) - Patients with Bronchospastic Diseases Should in General Not Receive Beta-Blockers Pindolol tablets should be administered with caution since it may block bronchodilation produced by endogenous or exogenous catecholamine stimulation of beta 2 receptors. Major Surgery Because beta blockade impairs the ability of the heart to respond to reflex stimuli and may increase the risks of general anesthesia and surgical procedures, resulting in protracted hypotension or low cardiac output, it has generally been suggested that such therapy should be gradually withdrawn several days prior to surgery. Recognition of the increased sensitivity to catecholamines of patients recently withdrawn from beta-blocker therapy, however, has made this recommendation controversial. If possible, beta-blockers should be withdrawn well before surgery takes place. In the event of emergency surgery, the anesthesiologist should be informed that the patient is on beta-blocker therapy. The effects of pindolol tablets can be reversed by administration of beta-receptor agonists such as isoproterenol, dopamine, dobutamine, or norepinephrine. Difficulty in restarting and maintaining the heart beat has also been reported with beta-adrenergic receptor blocking agents. Diabetes and Hypoglycemia Beta-adrenergic blockade may prevent the appearance of premonitory signs and symptoms (e.g., tachycardia and blood pressure changes) of acute hypoglycemia. This is especially important with labile diabetics. Beta-blockade also reduces the release of insulin in response to hyperglycemia; therefore, it may be necessary to adjust the dose of antidiabetic drugs. Thyrotoxicosis Beta-adrenergic blockade 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-blockade which might precipitate a thyroid crisis.

Drug Interactions Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients receiving pindolol tablets plus a catecholamine-depleting agent should, therefore, be closely observed for evidence of hypotension and/or marked bradycardia which may produce vertigo, syncope, or postural hypotension. Pindolol tablets have been used with a variety of antihypertensive agents, including hydrochlorothiazide, hydralazine, and guanethidine without unexpected adverse interactions. Pindolol tablets have been shown to increase serum thioridazine levels when both drugs are coadministered. Pindolol levels may also be increased with this combination. Risk of Anaphylactic Reaction While taking beta blockers, patients with a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction.

ADVERSE REACTIONS Most adverse reactions have been mild. The incidences listed in the following table are derived from 12-week comparative double-blind, parallel design trials in hypertensive patients given pindolol tablets as monotherapy, given various active control drugs as monotherapy, or given placebo. Data for pindolol tablets and the positive controls were pooled from several trials because no striking differences were seen in the individual studies, with one exception. When considering all adverse reactions reported, the frequency of edema was noticeably higher in positive control trials [16% pindolol tablets vs. 9% positive control] than in placebo controlled trials [6% pindolol tablets vs. 3% placebo]. The table includes adverse reactions either volunteered or elicited, and at least possibly drug related, which were reported in greater than 2% of pindolol tablets patients and other selected important reactions. ADVERSE REACTIONS WHICH WERE VOLUNTEERED OR ELICITED (and at least possibly drug-related) Body System/ Adverse Reactions Pindolol Tablets (N = 322) % Active Controls Active Controls: Patients received either propranolol, a-methyldopa or a diuretic (hydrochlorothiazide or chlorthalidone). (N = 188) % Placebo (N = 78) % Central Nervous System Bizarre or Many Dreams 5 0 6 Dizziness 9 11 1 Fatigue 8 4 4 Hallucinations <1 0 0 Insomnia 10 3 10 Nervousness 7 3 5 Weakness 4 2 1 Autonomic Nervous System Paresthesia 3 1 6 Cardiovascular Dyspnea 5 4 6 Edema 6 3 1 Heart Failure <1 <1 0 Palpitations <1 1 0 Musculoskeletal Chest Pain 3 1 3 Joint Pain 7 4 4 Muscle Cramps 3 1 0 Muscle Pain 10 9 8 Gastrointestinal Abdominal Discomfort 4 4 5 Nausea 5 2 1 Skin Pruritus 1 <1 0 Rash <1 <1 1 The following selected (potentially important) adverse reactions were seen in 2% or fewer patients and their relationship to pindolol tablets is uncertain. CENTRAL NERVOUS SYSTEM: anxiety, lethargy; AUTONOMIC NERVOUS SYSTEM: visual disturbances, hyperhidrosis; CARDIOVASCULAR: bradycardia, claudication, cold extremities, heart block, hypotension, syncope, tachycardia, weight gain; GASTROINTESTINAL: diarrhea, vomiting; RESPIRATORY: wheezing; UROGENITAL: impotence, pollakiuria; MISCELLANEOUS: eye discomfort or burning eyes. POTENTIAL ADVERSE EFFECTS In addition, other adverse effects not aforementioned have been reported with other beta-adrenergic blocking agents and should be considered potential adverse effects of pindolol tablets. Central 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 CONTRAINDICATIONS .) Allergic: Erythematous rash; fever combined with aching and sore throat; laryngospasm; respiratory distress. Hematologic: Agranulocytosis; thrombocytopenic and nonthrombocytopenic purpura. Gastrointestinal: Mesenteric arterial thrombosis; ischemic colitis. Miscellaneous: Reversible alopecia; Peyronie's disease. The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been reported with pindolol tablets during investigational use and extensive foreign experience amounting to over 4 million patient-years.

Pregnancy Teratogenic Effects. Category B Studies in rats and rabbits exceeding 100 times the maximum recommended human doses, revealed no embryotoxicity or teratogenicity. Since there are no adequate and well-controlled studies in pregnant women, and since animal reproduction studies are not always predictive of human response, pindolol tablets, as with any drug, should be employed during pregnancy only if the potential benefit justifies the potential risk to the fetus.