Active ingredient: Pindolol - Brands, Medical Use, Clinical Data

Brands, Medical Use, Clinical Data

Drug Category

• Vasodilator Agents
• Antihypertensive Agents
• Adrenergic beta-Antagonists
• Serotonin Antagonists

Dosage Forms

• Tablet

Brands / Synonyms

Betapindol; Blockin L; Blocklin L; Calvisken; Cardilate; Decreten; Durapindol; Glauco-Visken; Pectobloc; Pinbetol; Prinodolol; Pynastin; Visken; Visken

Indications

For the management of hypertension, edema, ventricular tachycardias, and atrial fibrillation.

Pharmacology

Pindolol is a non-selective beta-adrenergic antagonist (beta-blocker) which possesses intrinsic sympathomimetic activity (ISA) in therapeutic dosage ranges but does not possess quinidine-like membrane stabilizing activity. Pindolol impairs AV node conduction and decreases sinus rate and may also increase plasma triglycerides and decrease HDL-cholesterol levels. Pindolol is nonpolar and hydrophobic, with low to moderate lipid solubility. Pindolol has little to no intrinsic sympathomimetic activity and, unlike some other beta-adrenergic blocking agents, pindolol has little direct myocardial depressant activity and does not have an anesthetic-like membrane-stabilizing action.

Mechanism of Action

Pindolol non-selectively blocks beta-1 adrenergic receptors mainly in the heart, inhibiting the effects of epinephrine and norepinephrine resulting in a decrease in heart rate and blood pressure. By binding beta-2 receptors in the juxtaglomerular apparatus, Pindolol inhibits the production of renin, thereby inhibiting angiotensin II and aldosterone production and therefore inhibits the vasoconstriction and water retention due to angiotensin II and aldosterone, respectively.

Absorption

Rapidly and reproducibly absorbed (bioavailability greater than 95%).

Toxicity

LD₅₀=263 mg/kg (orally in rats). Signs of overdose include excessive bradycardia, cardiac failure, hypotension, and bronchospasm.

Biotrnasformation / Drug Metabolism

Hepatic. In man, 35% to 40% is excreted unchanged in the urine and 60% to 65% is metabolized primarily to hydroxy-metabolites which are excreted as glucuronides and ethereal sulfates.

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.

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 co-administered. 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.