Pindolol

Absorption

The mean oral bioavailability of pindolol is 87-92%. A 5 mg oral dose reaches a Cmax of 33.1?± 5.2 ng/mL, with a Tmax of 1-2 hours.

Toxicity

Patients experiencing an overdose may experience excessive bradycardia, cardiac failure, hypotension, and bronchospasm. Initiate treatment with symptomatic and supportive measures.

Chemical properties

White Solid

Originator

Betadren, Lagap

The Uses of Pindolol

Pindolol, like nadolol, is a nonselective β-adrenoblocker. It possesses antianginal, antihypotensive, and antiarrythmic action. It is used for arterial hypertension, angina stress (preventing attacks), supraventricular tachycardia, tachsystolic form of atrial fibrillation, and superventricular extrasystole.

The Uses of Pindolol

Mixed β-adrenergic blocker and serotonin 5HT1A-receptor antagonist. Antihypertensive; antianginal; antiarrhythmic; antiglaucoma.

Indications

Pindolol is indicated in the management of hypertension. In Canada, it is also indicated in the prophylaxis of angina.

Background

Pindolol is a first generation non-selective beta blocker used in the treatment of hypertension. Early research into the use of pindolol found it had chronotropic effects, and so further investigation focused on the treatment of arrhythmia. Research into pindolol's use in the treatment of hypertension began in the early 1970s.
Pindolol was granted FDA approval on 3 September 1982.

What are the applications of Application

Pindolol is a SR-1A/SR-1B antagonist

Definition

ChEBI: A member of the class of indols which is the 2-hydroxy-3-(isopropylamino)propyl ether derivative of 1H-indol-4-ol.

Manufacturing Process

4-Hydroxyindole is obtained by debenzylation of 4-benzyloxyindole with hydrogen in the presence of a 5% palladium catalyst on aluminium oxide.
10.0 g of 4-hydroxyindole and subsequently 7.4 ml of epichlorohydrin are added while stirring in an atmosphere of nitrogen to a solution of 2.73 g of sodium hydroxide in 65 ml of water. Stirring is effected at room temperaturefor a further 15 h, the reaction mixture is extracted 4 times with 50 ml of methylene chloride and the combined organic layers which have been dried over magnesium sulfate are evaporated at reduced pressure. So 3-chloro-1(4-indolyloxy)-2-propanol is obtained.
The 3-chloro-1-(4-indolyloxy)-2-propanol is dissolved in 50 ml of toluene and 50 ml of isopropylamine and heated to the boil for 45 h. Evaporation to dryness is effected in a vacuum, the residue is shaken out thrice between ethyl acetate and a 1 N tartaric acid solution and a 5 N sodium hydroxide solution is then added to the combined tartaric acid phases until an alkaline reaction is obtained. The alkaline solution is shaken out thrice with 50 ml of methylene chloride, the extracts are dried over magnesium sulfate and the solvent evaporated in vacuum. The residue is crystallized from ethyl acetate/ether to give the 4-(2-hydroxy-3-isopropylaminopropoxy)indole.

brand name

Visken (Novartis).

Therapeutic Function

Beta-adrenergic blocker

Biological Activity

5-HT 1A/1B ? receptor antagonist, with roughly equal affinity for each subtype. A partial agonist at mouse and human β 3 -adrenoceptors.

Biochem/physiol Actions

β1-adrenoceptor antagonist; putative 5-HT1A serotonin receptor agonist; vasodilator.

Pharmacokinetics

Pindolol is a nonselective beta blocker indicated in the management of hypertension and prophylaxis of angina. It has a short duration of action as it is given twice daily, and a wide therapeutic window as doses can range from 10-60 mg/day. Patients should be counselled regarding the risk of cardiac failure, exacerbating ischemic heart disease with sudden withdrawal, nonallergic bronchospasm, masking hypoglycemia in diabetics, and masking hyperthyroidism.

Clinical Use

Beta-blocker:
Hypertension
Angina

Drug interactions

Potentially hazardous interactions with other drugs
Anaesthetics: enhanced hypotensive effect.
Analgesics: NSAIDs antagonise hypotensive effect.
Anti-arrhythmics: increased risk of myocardial depression and bradycardia; increased risk of bradycardia, myocardial depression and AV block with amiodarone; increased risk of myocardial depression and bradycardia with flecainide.
Antidepressants: enhanced hypotensive effect with MAOIs.
Antihypertensives; enhanced hypotensive effect; increased risk of withdrawal hypertension with clonidine; increased risk of first dose hypotensive effect with post-synaptic alpha-blockers such as prazosin.
Antimalarials: increased risk of bradycardia with mefloquine.
Antipsychotics: enhanced hypotensive effect with phenothiazines.
Calcium-channel blockers: increased risk of bradycardia and AV block with diltiazem; hypotension and heart failure possible with nifedipine and nisoldipine; asystole, severe hypotension and heart failure with verapamil.
Cytotoxics: possible increased risk of bradycardia with crizotinib.
Diuretics: enhanced hypotensive effect.
Fingolimod: possibly increased risk of bradycardia.
Moxisylyte: possible severe postural hypotension.
Sympathomimetics: severe hypertension with adrenaline and noradrenaline and possibly with dobutamine.

Metabolic pathway

Several metabolites of pindolol formed in vitro are detected after a 24 h incubation of human hepatocytes in both pure culture and co-culture by adding rat liver epithelial cells. The hepatocytes are able to oxidize the isopropyl amine moiety and the pyrrole ring of the indole moiety and conjugate pindolol as sulfates and glucuronides.

Metabolism

30-40% of a dose of pindolol is not metabolized. The remainder is hydroxylated and subsequently undergoes glucuronidation or sulfate conjugation.

Metabolism

Pindolol (Visken) is extensively absorbed from the gastrointestinal tract. First-pass metabolism is estimated at about 15%, and its plasma half-life is on the order of 3 to 4 hours.The binding of pindolol to plasma proteins is approximately 50%.The metabolic fate of pindolol is not completely understood, although 50% of an administered dose is recovered, primarily in the urine, as unchanged drug.