Vanoxin

Vanoxin - General Information

A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone digoxigenin. Vanoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666)

Pharmacology of Vanoxin

Vanoxin, a cardiac glycoside similar to digitoxin, is used to treat congestive heart failure and supraventricular arrhythmias due to reentry mechanisms, and to control ventricular rate in the treatment of chronic atrial fibrillation.

Vanoxin for patients

Digoxin is used for the treatment of congestive heart failure and for irregular heartbeat. Notify your physician if you are pregnant or nursing. Do not stop taking digoxin without talking with your physician. Digoxin may be taken with or without food. It should be taken at approximately the same time each morning. Do not take over-the-counter antacids, cough, cold, allergy or diet medications without notifying your physician and pharmacist. Notify your physician if you develop an irregular heartbeat, trouble breathing, skin rash, nausea, diarrhea, blurred or yellow vision, or unusual weakness or tiredness.

Vanoxin Interactions

Potassium-depleting diuretics are a major contributing factor to digitalis toxicity. Calcium, particularly if administered rapidly by the intravenous route, may produce serious arrhythmias in digitalized patients. Quinidine, verapamil, amiodarone, propafenone, indomethacin, itraconazole, alprazolam, and spironolactone raise the serum digoxin concentration due to a reduction in clearance and/or in volume of distribution of the drug, with the implication that digitalis intoxication may result. Erythromycin and clarithromycin (and possibly other macrolide antibiotics) and tetracycline may increase digoxin absorption in patients who inactivate digoxin by bacterial metabolism in the lower intestine, so that digitalis intoxication may result. The risk of this interaction may be reduced if digoxin is given as capsules. Propantheline and diphenoxylate, by decreasing gut motility, may increase digoxin absorption. Antacids, kaolin-pectin, sulfasalazine, neomycin, cholestyramine, certain anticancer drugs, and metoclopramide may interfere with intestinal digoxin absorption, resulting in unexpectedly low serum concentrations. Rifampin may decrease serum digoxin concentration, especially in patients with renal dysfunction, by increasing the non-renal clearance of digoxin. There have been inconsistent reports regarding the effects of other drugs (e.g., quinine, penicillamine) on serum digoxin concentration. Thyroid administration to a digitalized, hypothyroid patient may increase the dose requirement of digoxin. Concomitant use of digoxin and sympathomimetics increases the risk of cardiac arrhythmias. Succinylcholine may cause a sudden extrusion of potassium from muscle cells, and may thereby cause arrhythmias in digitalized patients. Although beta-adrenergic blockers or calcium channel blockers and digoxin may be useful in combination to control atrial fibrillation, their additive effects on AV node conduction can result in advanced or complete heart block.

Due to the considerable variability of these interactions, the dosage of digoxin should be individualized when patients receive these medications concurrently. Furthermore, caution should be exercised when combining digoxin with any drug that may cause a significant deterioration in renal function, since a decline in glomerular filtration or tubular secretion may impair the excretion of digoxin.

Vanoxin Contraindications

Digitalis glycosides are contraindicated in patients with ventricular fibrillation or in patients with a known hypersensitivity to digoxin. A hypersensitivity reaction to other digitalis preparations usually constitutes a contraindication to digoxin.

Additional information about Vanoxin

Vanoxin Indication: For the treatment and management of congestive cardiac insufficiency, arrhythmias and heart failure.
Mechanism Of Action: Vanoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Vanoxin also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential.
Drug Interactions: Acarbose Acarbose decreases the effect of digoxin
Alprazolam The benzodiazepine increases the effect of digoxin
Amiodarone Amiodarone increases the effect of digoxin
Bendroflumethiazide Possible electrolyte variations and arrhythmias
Benzthiazide Possible electrolyte variations and arrhythmias
Bleomycin The antineoplasic agent decreases the effect of digoxin
Bumetanide Possible electrolyte variations and arrhythmias
Carmustine The antineoplasic agent decreases the effect of digoxin
Carvedilol Carvedilol increases levels/effect of digoxin
Chlorothiazide Possible electrolyte variations and arrhythmias
Chlorthalidone Possible electrolyte variations and arrhythmias
Cholestyramine The resin decreases the effect of digoxin
Clarithromycin The macrolide increases the effect of digoxin in 10% of patients
Colestipol The resin decreases the effect of digoxin
Cyclophosphamide The antineoplasic agent decreases the effect of digoxin
Cyclosporine Cyclosporine increases the effect of digoxin
Cyclothiazide Possible electrolyte variations and arrhythmias
Cytarabine The antineoplasic agent decreases the effect of digoxin
Demeclocycline The tetracycline increases the effect of digoxin in 10% of patients
Dextrothyroxine The thyroid hormone decreases the effect of digoxin
Diazepam The benzodiazepine increases the effect of digoxin
Dihydroquinidine barbiturate Quinine/quinidine increases the effect of digoxin
Doxorubicin The antineoplasic agent decreases the effect of digoxin
Doxycycline The tetracycline increases the effect of digoxin in 10% of patients
Erythromycin The macrolide increases the effect of digoxin in 10% of patients
Ethacrynic acid Possible electrolyte variations and arrhythmias
Furosemide Possible electrolyte variations and arrhythmias
Gatifloxacin Gatifloxacin increases the effect of digoxin
Ginseng Changes in digoxin serum levels
Hydrochlorothiazide Possible electrolyte variations and arrhythmias
Hydroflumethiazide Possible electrolyte variations and arrhythmias
Itraconazole Itraconazole increases the effect of digoxin
Indapamide Possible electrolyte variations and arrhythmias
Josamycin The macrolide increases the efect of digoxin in 10% of patients
Levothyroxine The thyroid hormones decreases the effect of digoxin
Liothyronine The thyroid hormones decreases the effect of digoxin
Methacycline The tetracycline increases the effect of digoxin in 10% of patients
Methimazole The antithyroid agent increases the effect of digoxin
Methyclothiazide Possible electrolyte variations and arrhythmias
Metolazone Possible electrolyte variations and arrhythmias
Minocycline The tetracycline increases the effect of digoxin in 10% of patients
Oxytetracycline The tetracycline increases the effect of digoxin in 10% of patients
Penicillamine Penicillamine decreases the effect of digoxin
Polythiazide Possible electrolyte variations and arrhythmias
Prazosin Prazosin increases the effect of digoxin
Procarbazine The antineoplasic agent decreases the effect of digoxin
Propafenone Propafenone increases the effect of digoxin
Propylthiouracil The antithyroid agent increases the effect of digoxin
Quinethazone Possible electrolyte variations and arrhythmias
Quinidine Quinine/quinidine increases the effect of digoxin
Quinidine barbiturate Quinine/quinidine increases the effect of digoxin
Rabeprazole Rabeprazole increases the effect of digoxin
Ranolazine Ranolazine increases digoxin's levels
Ritonavir Ritonavir increases levels/effect of digoxin
Rolitetracycline The tetracycline increases the effect of digoxin in 10% of patients
Spironolactone Increased digoxin levels and decreased effect in presence of spironolactone
St. John's Wort St. John's Wort decreases the effect of digoxin
Sulfasalazine Sulfasalazine decreases the effect of digoxin
Telithromycin Telithromycin may increase levels of digoxin
Telmisartan Telmisartan increases the effect of digoxin
Tetracycline The tetracycline increases the effect of digoxin in 10% of patients
Tolbutamide Tolbutamide increases the effect of digoxin
Trichlormethiazide Possible electrolyte variations and arrhythmias
Verapamil Verapamil increases the effect of digoxin
Vincristine The antineoplasic agent decreases the effect of digoxin
Methotrexate The antineoplasic agent decreases the effect of digoxin
Hydroxychloroquine Hydroxychloroquine increases the effect of digoxin
Liotrix The thyroid hormone decreases the effect of digoxin
Thyroglobulin (Tg) The thyroid hormone decreases the effect of digoxin
Quinine Quinine/quinidine increases the effect of digoxin
Food Interactions: Avoid bran and high fiber foods within 2 hours of taking this medication.
Avoid excess salt/sodium unless otherwise instructed by your physician.
Avoid salt substitutes containing potassium.
Avoid milk, calcium containing dairy products, iron, antacids, or aluminum salts 2 hours before or 6 hours after using antacids while on this medication.
Limit garlic, ginger, gingko, and horse chestnut.
Avoid avocado.
Generic Name: Digoxin
Synonyms: Digitalis Glycoside
Drug Category: Cardiotonic Agents; Antiarrhythmic Agents
Drug Type: Small Molecule; Approved

Other Brand Names containing Digoxin: Cardoxin; Cogoxin; Cordioxil; Davoxin; Digacin; Digitekt; Digoxin Pediatric; Dilanacin; Dixina; Dokim; Dynamos; Eudigox; Homolle's Digitalin; Lanacordin; Lanacrist; Lanicor; Lanoxicaps; Lanoxin; Lenoxicaps; Lenoxin; Longdigox; Neo-Lanicor; Neodioxanin; Rougoxin; SK-Digoxin; Stillacor; Vanoxin;
Absorption: Absorption of digoxin from the elixir pediatric formulation has been demonstrated to be 70% to 85% complete (90% to 100% from the capsules, and 60% to 80% for tablets).
Toxicity (Overdose): Toxicity includes ventricular tachycardia or ventricular fibrillation, or progressive bradyarrhythmias, or heart block. LD₅₀ = 7.8 mg/kg (orally in mice).
Protein Binding: 25%
Biotransformation: Hepatic (but not dependent upon the cytochrome P-450 system). The end metabolites, which include 3 b-digoxigenin, 3-keto-digoxigenin, and their glucuronide and sulfate conjugates, are polar in nature and are postulated to be formed via hydrolysis, oxidation, and conjugation.
Half Life: 3.5 to 5 days
Dosage Forms of Vanoxin: Liquid Intravenous
Powder, for solution Intravenous
Tablet Oral
Solution Oral
Chemical IUPAC Name: 4-[(3S,5R,8R,9S,10S,12R,13S,14S)-3-[(2R,4S,5S,6R)-5-[(2S,4S,5S,6R)-5-[(2S,4S,5S,6R)-4,5-dihydroxy-6-methyloxan-2-yl]oxy-4-hydroxy-6-methyloxan-2-yl]oxy-4-hydroxy-6-methyloxan-2-yl]oxy-12,14-dihydroxy-10,13-dimethyl-1,2,3,4,5,6,7,8,9,11,12,15,16,17-tetradecahydrocyclopenta[a]phenanthren-17-yl]-5H-furan-2-one
Chemical Formula: C41H64O14
Digoxin on Wikipedia: https://en.wikipedia.org/wiki/Digoxin
Organisms Affected: Humans and other mammals