Pindolol

Description

DESCRIPTION Pindolol, a synthetic beta-adrenergic receptor blocking agent with intrinsic sympathomimetic activity is 1-(Indol-4-yloxy)-3-(isopropylamino)-2-propanol. Pindolol, USP is a white to off-white, crystalline powder having a faint odor which is practically insoluble in water; slightly soluble in methanol; and very slightly soluble in chloroform. Each tablet for oral administration contains pindolol and the following inactive ingredients: crospovidone, lactose, magnesium stearate, microcrystalline cellulose, and pregelatinized starch. Structure

What Is Pindolol Used For?

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

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.

Side Effects (Adverse Reactions)

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 as monotherapy, given various active control drugs as monotherapy, or given placebo. Data for pindolol 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 vs. 9% positive control) than in placebo controlled trials (6% pindolol 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 patients and other selected important reactions. ADVERSE REACTIONS WHICH WERE VOLUNTEERED OR ELICITED (and at least possibly drug-related) Body System/ Adverse Reactions Pindolol (N = 322) % Central Nervous System Bizarre or Many Dreams 5 Dizziness 9 Fatigue 8 Hallucinations < 1 Insomnia 10 Nervousness 7 Weakness 4 Autonomic Nervous System Paresthesia 3 Cardiovascular Dyspnea 5 Edema 6 Heart Failure < 1 Palpitations < 1 Musculoskeletal Chest Pain 3 Joint Pain 7 Muscle Cramps 3 Muscle Pain 10 Gastrointestinal Abdominal Discomfort 4 Nausea 5 Skin Pruritus 1 Rash < 1 Body System/ Adverse Reactions Active Controls Active Controls: Patients received either propranolol, α-methyldopa or a diuretic (hydrochlorothiazide or chlorthalidone). (N = 188) % Central Nervous System Bizarre or Many Dreams 0 Dizziness 11 Fatigue 4 Hallucinations 0 Insomnia 3 Nervousness 3 Weakness 2 Autonomic Nervous System Paresthesia 1 Cardiovascular Dyspnea 4 Edema 3 Heart Failure < 1 Palpitations 1 Musculoskeletal Chest Pain 1 Joint Pain 4 Muscle Cramps 1 Muscle Pain 9 Gastrointestinal Abdominal Discomfort 4 Nausea 2 Skin Pruritus < 1 Rash < 1 Body System/ Adverse Reactions Placebo (N = 78) % Central Nervous System Bizarre or Many Dreams 6 Dizziness 1 Fatigue 4 Hallucinations 0 Insomnia 10 Nervousness 5 Weakness 1 Autonomic Nervous System Paresthesia 6 Cardiovascular Dyspnea 6 Edema 1 Heart Failure 0 Palpitations 0 Musculoskeletal Chest Pain 3 Joint Pain 4 Muscle Cramps 0 Muscle Pain 8 Gastrointestinal Abdominal Discomfort 5 Nausea 1 Skin Pruritus 0 Rash 1 The following selected (potentially important) adverse reactions were seen in 2% or fewer patients and their relationship to pindolol 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. 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 during investigational use and extensive foreign experience amounting to over 4 million patient-years.

Drug Interactions

Drug Interactions Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients receiving pindolol 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 has been used with a variety of antihypertensive agents, including hydrochlorothiazide, hydralazine, and guanethidine without unexpected adverse interactions. Pindolol has 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 reactions.

Contraindications

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. )

Pregnancy and Breastfeeding

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, as with any drug, should be employed during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers Since pindolol is secreted in human milk, nursing should not be undertaken by mothers receiving the drug.

Overdosage

OVERDOSAGE No specific information on emergency treatment of overdosage is available. Therefore, on the basis of the pharmacologic actions of pindolol, the following general measures should be employed as appropriate in addition to gastric lavage: Excessive Bradycardia: administer atropine; if there is no response to vagal blockade, administer isoproterenol cautiously. Cardiac Failure: digitalize the patient and/or administer diuretic. It has been reported that glucagon may be useful in this situation. Hypotension: administer vasopressors, e.g., epinephrine or norepinephrine, with serial monitoring of blood pressure. (There is evidence that epinephrine may be the drug of choice.) Bronchospasm: administer a beta 2 stimulating agent such as isoproterenol and/or a theophylline derivative. A case of an acute overdosage has been reported with an intake of 500 mg of pindolol by a hypertensive patient. Blood pressure increased and heart rate was ≥ 80 beats/min. Recovery was uneventful. In another case, 250 mg of pindolol was taken with 150 mg diazepam and 50 mg nitrazepam, producing coma and hypotension. The patient recovered in 24 hours.

How Supplied

HOW SUPPLIED Pindolol Tablets, USP are available as 10 mg tablets. The 10 mg tablets are round white tablets, debossed "MP 183" bisected on one side and blank on the other side. Bottles of 100 NDC 72789-293-01 Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature] Protect from light. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.