Kwit, walter modell, elaine cotlove, joseph benton and harold l. Drug related interventions may focus on education strategies about a drugs action, adverse effects, scheduling, steps to avoid, treating drug reaction, as well as drug administration techniques including compliance. Jpet articles become freely available 12 months after publication, and remain freely available for 5 years. Concurrent use of another drug that increases the action of these drugs further increases risk of adverse effects. Otto journal of pharmacology and experimental therapeutics september 1. Digoxin is a selective inhibitor of the plasma membrane sodium pump.
Commonly reported clinically meaningful drug interactions are listed in table 3. Drugs az pill identifier supplements symptom checker diseases dictionary media. Digoxin is extracted from the leaves of the foxglove plant digitalis lanata. The history of digitalis is rich and interesting, with the first use usually attributed.
By its positive inotropic effect, digoxin increases the cardiac muscular force of contraction. This page includes the following topics and synonyms. Drug interactions and clinical pharmacology learn about from the msd manuals medical professional version. Digoxin has been considered the gold standard probe for pglycoprotein activity because it mediates secretion of digoxin across the apical membrane of the renal tubular epithelium 49, 50. Digoxin is effective for rate control in patients with atrial fibrillation, but its influence on mortality rates is a source of controversy. Hebert, in clinical pharmacology during pregnancy, 20. Most frequently it is used for atrial fibrillation, atrial flutter, and heart failure. Start studying pharmacology digoxin and congestive heart failure. For additional research on potential drugdrug interactions, consult a reliable source, such as s drugs interaction checker.
Digoxin exists as odorless white crystals that are. Digoxin belongs to a class of medications called cardiac glycosides. Digoxin, sold under the brand name lanoxin among others, is a medication used to treat. Assess heart rate, ecg, and heart sounds, especially during exercise see appendices g, h.
This drug should be considered a narrow therapeutic index nti drug as small differences in dose or blood concentrations may lead to serious therapeutic failures or adverse drug reactions. Clinical pharmacokinetics of digitoxin university of arizona. The pharmacological and toxic action of digoxin journal of. Furosemide, hydrochlorothiazide, spironolactone 18. The therapeutic benefits of digitalis were first described by william withering in 1785. Digoxin rxlist the internet drug index for prescription. Digoxin casebook in clinical pharmacokinetics and drug. Pharmacokinetic considerations for digoxin in older people. Semsarian, the author of digoxin in the 21st century, comments. Digoxin is roughly 30 percent protein bound in the plasma and has a large volume of distribution vd of nearly 7 lkg in healthy adults. Find information on digoxin lanoxin in daviss drug guide including dosage, side effects, interactions, nursing implications, mechanism of action, half life, administration, and more. Clinical pharmacology msd manual professional edition. Apr 18, 2017 the affinity of digibind digoxin immune fab for digoxin is in the range of 10 9 to 10 11 m1, which is greater than the affinity of digoxin for sodium, potassium atpase, the presumed receptor for its toxic effects.
Generic substitution should be done cautiously, if at all, as current bioequivalence standards are generally insufficient for nti drugs. The related drug information index provides comprehensive access to all drug information related to a specific drug types of content include full prescribing information, drug summaries, full prescribing information continuing medication education full pi cme, medication guides, risk evaluation and mitigation strategies rems summaries, rems continuing medication. How to pronounce digoxin lanoxin memorizing pharmacology. Digoxin drug interactions in more detail further information remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use digoxin only for the indication prescribed. Initially, digitalis was used to treat dropsy, which is an old term for edema. The digoxin molecule is composed of a sugar and a cardenolide.
The use of digoxin is limited because the drug has a narrow therapeutic index and requires close monitoring. A more important factor is erythromycin inhibition of pglycoprotein pgp, an energydependent drug efflux pump. Digoxin, produced halfsynthetically from digitalis lanata, leads to increased myocardial contraction positive inotropic effect and thus to more performant pumping. Pglycoprotein and organic anion transporter polypeptides. Inhibition of this protein in the intestinal cell wall leads to increased oral absorption and decreased renal and nonrenal clearance of digoxin. More than 200 years ago, sir william withering observed that foxglove flower derivative digitalis purpura could be used for cardiac dropsy. In the cat and frog, it is one fourth as toxic as ouabain, while its. A drugdrug interaction may increase or decrease the effects of one or both drugs.
The pathophysiologic basis of drug therapy, 2nd edition. The role of digoxin in the treatment of each of these disease states has changed in recent years as a better understanding of the pathophysiology of these conditions has been gained and new drug therapies have been developed. Jun 10, 2016 pronunciation flashcards for the print, e book, and pharmacology audiobook memorizing pharmacology. Sep 18, 2019 take the medicine at the same time each day. Director clinical pharmacology program office of clinical research training and medical education national institutes of health clinical center september 3, 2015 lipsett amphitheater. Digoxin helps the heart work normally by controlling the amount of calcium that goes into the heart muscle. It involves inhibiting the system of sodium and potassium exchange in and out of the cell. Penicillin is an example of a highly selective drug, since it works specifically by inhibiting cell wall synthesis, and other than allergic responses it has very little effect on human cells at normal doses. Impaired kidney function is the most important condition with an influence on the pharmacokinetics of digoxin. The affinity of digibind digoxin immune fab for digitoxin is about 10 8 to 10 9 m1. Pronunciation flashcards for the print, ebook, and pharmacology audiobook memorizing pharmacology.
Production of antibodies specific for digoxin involves conjugation of digoxin as a hapten to human albumin. Digoxin is extensively distributed in the tissues, as reflected by the large volume of distribution. Digibind, digoxin immune fab ovine, is a sterile lyophilized powder of antigen binding fragments fab derived from specific antidigoxin antibodies raised in sheep. Although digoxin is invaluable for a variety of cardiovascular diseases, and it is virtually the only cardiac glycoside in common use today in children and infants, it is known to have a low margin of safety. A cardiac glycoside extracted from the foxglove plant, digitalis lanata, it is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation, but the margin between toxic and therapeutic doses is small. Some of the brands for digoxin might be better known than digoxin itself. Digoxin is used to treat heart failure digoxin is also used to treat atrial fibrillation, a heart rhythm disorder of the atria the upper chambers of the heart that allow blood to flow into the heart important information. Review side effects, drug interactions, dosage, and pregnancy and breastfeeding information before using this medication. Your doctor will determine the proper dose of digoxin for you. Digoxin is a cardioactive drug that is only 25% bound to serum proteins, mainly albumin. Digoxin is used to treat heart failure, usually along with other medications. Digoxin lanoxin daviss drug guide unbound medicine. A second, slower distribution phase soon occurs and. Apr 19, 2018 on this episode i explain digoxin pharmacology and also run through some scenarios where ive seen digoxin toxicity actually happen.
The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects. Digoxin cardiac glycoside diuretics l loop diuretics, thiazide diuretics, potassium sparing diuretics. Heart failure pharmacology ace, arbs, beta blockers. N2 the disposition kinetics of digitoxin have not been as thoroughly examined as those of digoxin. Digoxin is used in several cardiac pathologies such as atrial fibrillation and heart failure. Even when used alone, these drugs may have serious adverse effects.
Digoxin, a glycoside isolated from the leaves of digitalis lanata, possesses the general characteristics of the digitalis group of cardiac glycosides. The pharmacodynamic effects of digoxin, including toxic symptoms, are correlated with the uptake of digoxin in the heart after a single dose and with the steady state serum digoxin concentration during maintenance therapy. Nonopen access articles that fall outside this five year window are available only to institutional subscribers and current aspet members, or through the article purchase feature at the bottom of the page. Dec, 2012 the pharmacodynamic effects of digoxin, including toxic symptoms, are correlated with the uptake of digoxin in the heart after a single dose and with the steady state serum digoxin concentration during maintenance therapy. Digoxin works best when there is a constant amount in the blood. Cv pharmacology cardiac glycosides digitalis compounds. Verapamil, nifedipine, amiodarone used htn and arrhythmias, cause increase in plasma levels of digoxin from plasma binding. Digoxin digoxin dose, indications, adverse effects. Unfortunately, many therapeutic agents, like digoxin and theophylline, produce doserelated side effects near their therapeutic dose range. Although intended to treat certain atrial arrhythmias, digoxin can precipitate new and potentially serious arrhythmias proarrhythmic effect. Digoxin blood levels are used for adjusting doses in order to avoid toxicity.
Digoxin treats atrial fibrillation and heart failure. It is also being studied in the treatment of some types of cancer. At the same time, digoxin has a negative chronotropic effect that decreases heart rate by its influence on the cardiac electrical conduction pathway. Box 6998, chicago, illinois 60680 clinical pharmacology of digoxin lester f. Cardiac glycosides represent a family of compounds that are derived from the foxglove plant digitalis purpurea.
I also discuss the relationship of low potassium and how d. Your body may not absorb this drug as well if you also eat foods that are high in fiber or if you take certain medications. Digoxin is a medicine used in the treatment of various heart conditions. The publication, approved drug products commonly known as the orange book, identifies drug products approved on the basis of safety and effectiveness by the food and drug administration fda under the federal food, drug, and cosmetic act. Although digoxin is invaluable for a variety of cardiovascular diseases, and it is virtually the only cardiac glycoside in common use today in children and infants, it. Uses, side effects, interactions, pictures, warnings. It also may kill cancer cells and make them more sensitive to anticancer drugs. The degree of binding to serum albumin is 20 to 30%. The issue of determining whether or not a patients clinical status is due to a drug effect is an important one. Drugs which increase the efficiency of heart are called cardiotonic drugs. Digoxin is used for the treatment of congestive heart failure chf because of its. If the pharmacy thats willing to deliver medicines to your home doesnt have digoxin in stock, you can ask for one of the branded alternatives for digoxin.
Digoxin pharmacology your complete guide to digoxin. Digoxin casebook in clinical pharmacokinetics and drug dosing. Digoxin helps make the heart beat stronger and with a more regular rhythm. Dacvcp, in saunders handbook of veterinary drugs fourth edition, 2016. Because the initial volume of distribution v i of digoxin is relatively small 110v. Digoxin, sold under the brand name lanoxin among others, is a medication used to treat various heart conditions. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
This book is distributed under the terms of the creative commons. This excerpt explains digoxin effects on cardiac contractility and autonomic regulation of the electrophysiologic properties of the heart. A second, slower distribution phase soon occurs and moves the drug. Digoxin is classified as a cardiac glycoside and was initially approved by the fda in 1954. Clinical pharmacology of digoxin journal of pharmacology. Department of pharmacology and toxicology faculty of pharmaceutical sciences university of nigeria, nigeria. Quinidine antiarrhythmic, causes displacement of digoxin from binding sites as has high protein binding, plasma conc. Pharmacology digoxin and congestive heart failure quizlet. Digoxin is taken by mouth or by injection into a vein. The dose of digoxin will be different for different patients.
Choose from 219 different sets of pharmacology digoxin flashcards on quizlet. When you are taking digoxin, it is very important that you get the exact amount of medicine that you need. Digoxin is an antiarrhythmic drug that can help to maintain a proper heartbeat. Digoxin daviss drug guide for rehabilitation professionals. Serum concentrations of digoxin obtained before complete distribution are often misleading. Drug interactions might result in rapid increases in digoxin blood concentrations and related toxic symptoms. Digoxin pharmacology rlp episode 011 real life pharmacology. Aug 21, 2019 digoxin cardiac glycoside diuretics l loop diuretics, thiazide diuretics, potassium sparing diuretics.
It works by affecting certain minerals sodium and potassium inside heart cells. Digoxin is derived from the leaves of a digitalis plant. A drug used to treat irregular heartbeat and some types of heart failure. Capitals indicate lifethreatening, underlines indicate most frequent. Evaluation this is a systematic process for determining the effectiveness of nursing care.
Digoxin is taken by mouth or by injection into a vein common side effects include breast enlargement with other side effects generally due to an excessive dose. The pharmacology book is composed of 188 topic pages which are organized into 24 chapters. Its action on the blood pressure and the heart is similar to that of tincture of digitalis, and its actions on the respiration and intestine and arteries are also similar. Digoxin is a generic medicine name and there are several brands available for it. Digoxin is a cardenolide glycoside that is digitoxin betahydroxylated at c12. Learn about side effects, drug interactions, dosages, warnings, and more. Joel edwards dvm, dacvim cardiology, in small animal critical care medicine, 2009. Learn pharmacology digoxin with free interactive flashcards. Find information on digoxin lanoxin in daviss drug guide including dosage, side effects, interactions, nursing implications, mechanism of action, half life. Digoxin is a wellknown cardiac glycoside and one of the oldest drugs.