Betapindol - General Information
A moderately lipophilic beta blocker (adrenergic beta-antagonists). It is non-cardioselective and has intrinsic sympathomimetic actions, but little membrane-stabilizing activity. (From Martindale, The Extra Pharmocopoeia, 30th ed, p638)
Pharmacology of Betapindol
Betapindol 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. Betapindol impairs AV node conduction and decreases sinus rate and may also increase plasma triglycerides and decrease HDL-cholesterol levels. Betapindol is nonpolar and hydrophobic, with low to moderate lipid solubility. Betapindol 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.
Betapindol for patients
Patients, especially those with evidence of coronary artery insufficiency, should be warned against interruption or discontinuation of pindolol therapy without the physicianís advice. Although cardiac failure rarely occurs in properly selected patients, patients being treated with beta-adrenergic blocking agents should be advised to consult the physician at the first sign or symptom of impending failure.
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.
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.
Additional information about Betapindol
Betapindol Indication: For the management of hypertension, edema, ventricular tachycardias, and atrial fibrillation.
Mechanism Of Action: Betapindol 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, Betapindol 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.
Drug Interactions: Acetohexamide The beta-blocker decreases the symptoms of hypoglycemia
Chlorpropamide The beta-blocker decreases the symptoms of hypoglycemia
Clonidine Increased hypertension when clonidine stopped
Disopyramide The beta-blocker increases toxicity of disopyramide
Gliclazide The beta-blocker decreases the symptoms of hypoglycemia
Glipizide The beta-blocker decreases the symptoms of hypoglycemia
Glisoxepide The beta-blocker decreases the symptoms of hypoglycemia
Glibenclamide The beta-blocker decreases the symptoms of hypoglycemia
Glycodiazine The beta-blocker decreases the symptoms of hypoglycemia
Insulin The beta-blocker decreases the symptoms of hypoglycemia
Lidocaine The beta-blocker increases the effect and toxicity of lidocaine
Repaglinide The beta-blocker decreases the symptoms of hypoglycemia
Tolazamide The beta-blocker decreases the symptoms of hypoglycemia
Tolbutamide The beta-blocker decreases the symptoms of hypoglycemia
Verapamil Increased effect of both drugs
Chlorpromazine Increased effect of both drugs
Thioridazine Increased risk of cardiotoxicity and arrhythmias
Mesoridazine Increased risk of cardiotoxicity and arrhythmias
Aminophylline Antagonism of action and increased effect of theophylline
Dyphylline Antagonism of action and increased effect of theophylline
Oxtriphylline Antagonism of action and increased effect of theophylline
Theophylline Antagonism of action and increased effect of theophylline
Prazosin Risk of hypotension at the beginning of therapy
Ibuprofen Risk of inhibition of renal prostaglandins
Indomethacin Risk of inhibition of renal prostaglandins
Piroxicam Risk of inhibition of renal prostaglandins
Methyldopa Possible hypertensive crisis
Dihydroergotamine Ischemia with risk of gangrene
Dihydroergotoxine Ischemia with risk of gangrene
Diltiazem Increased risk of bradycardia
Epinephrine Hypertension, then bradycardia
Ergonovine Ischemia with risk of gangrene
Ergotamine Ischemia with risk of gangrene
Methysergide Ischemia with risk of gangrene
Food Interactions: Not Available
Generic Name: Pindolol
Synonyms: Not Available
Drug Category: Vasodilator Agents; Antihypertensive Agents; Adrenergic beta-Antagonists; Serotonin Antagonists
Drug Type: Small Molecule; Approved
Absorption: Rapidly and reproducibly absorbed (bioavailability greater than 95%).
Toxicity (Overdose): LD50=263 mg/kg (orally in rats). Signs of overdose include excessive bradycardia, cardiac failure, hypotension, and bronchospasm.
Protein Binding: 40%
Biotransformation: 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.
Half Life: 3 to 4 hours
Dosage Forms of Betapindol: Tablet Oral
Chemical IUPAC Name: 1-(1H-indol-4-yloxy)-3-(propan-2-ylamino)propan-2-ol
Chemical Formula: C14H20N2O2
Pindolol on Wikipedia: https://en.wikipedia.org/wiki/Pindolol
Organisms Affected: Humans and other mammals