Digitalis toxicity, also known as digoxin toxicity, refers to an overdose or accumulation of digitalis glycosides in the body. Digitalis glycosides are a class of medications derived from the foxglove plant, most commonly represented by the drug digoxin. These medications treat various heart conditions, including congestive heart failure, atrial fibrillation, and atrial flutter.
Digitalis glycosides work by inhibiting the sodium-potassium ATPase pump in cardiac cells, leading to increased intracellular calcium levels. This results in enhanced myocardial contractility slowed heart rate, and improved cardiac output. However, an excessive amount of digitalis glycosides can lead to toxicity, as the therapeutic window for these medications is relatively narrow.
Epidemiology
The prevalence of digitalis toxicity can vary depending on the population being studied and the specific criteria used for diagnosis. In general, digitalis toxicity is considered a relatively rare occurrence, especially when digitalis glycosides are used within the recommended therapeutic range. However, the incidence of toxicity increases with higher doses, older age, and the presence of underlying medical conditions that may affect drug metabolism or excretion.
Mortality rates associated with digitalis toxicity can also vary depending on the severity of the toxicity, promptness of medical intervention, and the overall health status of the affected individual. In mild to moderate toxicity cases, mortality rates are generally low, and most patients recover fully with appropriate treatment. However, severe cases of digitalis toxicity can be life-threatening and may lead to cardiac arrhythmias, cardiac arrest, or other complications that can increase mortality risk.
Anatomy
Pathophysiology
Digitalis glycosides inhibit the sodium-potassium ATPase pump, which maintains the intracellular and extracellular balance of sodium and potassium ions in cardiac cells. Inhibition of this pump leads to increased intracellular sodium levels, reduced extracellular potassium levels, and subsequent increase in intracellular calcium levels. The increase in intracellular calcium concentration results in enhanced myocardial contractility.
This positive inotropic effect is the desired therapeutic effect of digitalis glycosides in treating heart failure. However, excessive intracellular calcium levels can lead to dysregulation of cellular processes and contribute to toxicity. Elevated intracellular calcium levels can disturb the normal electrical conduction system of the heart. This can lead to cardiac arrhythmias, such as atrial and ventricular tachycardia, atrial fibrillation, or heart block. Arrhythmias can disrupt the heart’s normal rhythm and potentially lead to hemodynamic compromise.
Digitalis toxicity is often associated with hypokalemia and hypomagnesemia. These electrolyte imbalances can exacerbate the toxic effects of digitalis glycosides. Potassium and magnesium play a crucial role in maintaining the heart’s electrical stability, and their deficiencies can enhance the arrhythmogenic effects of digitalis glycosides. Digitalis toxicity can increase the automaticity of cardiac cells, leading to the generation of ectopic beats or abnormal pacemaker activity. This can contribute to the occurrence of arrhythmias.
Etiology
Accidental overdoses or administration of higher-than-prescribed doses of digitalis glycosides can lead to toxicity. This can occur due to errors in medication preparation, administration, or miscommunication. The kidneys play a crucial role in the excretion of digitalis glycosides from the body. Impaired renal function, such as chronic kidney disease, can reduce the clearance of these medications, leading to their accumulation and an increased risk of toxicity.
Certain medications can interact with digitalis glycosides, altering their metabolism or potentiating their effects. This can lead to increased concentrations of digitalis glycosides in the blood and an elevated risk of toxicity. Medications such as quinidine, verapamil, amiodarone, macrolide antibiotics, and some antifungals are known to interact with digitalis glycosides. Older individuals, especially those with multiple medical conditions, are generally at a higher risk of developing digitalis toxicity.
Age-related changes in drug metabolism and clearance and other illnesses affecting organ function can contribute to an increased susceptibility to toxicity. Genetic variations in drug metabolism enzymes or transporters may influence the response to digitalis glycosides. Some individuals may have a heightened sensitivity or reduced ability to metabolize and eliminate these medications, increasing the risk of toxicity.
Genetics
Prognostic Factors
Clinical History
Clinical History
The clinician will inquire about any pre-existing heart conditions, such as congestive heart failure, atrial fibrillation, or atrial flutter, for which digitalis glycosides may have been prescribed. Understanding the indication for digitalis glycoside use helps establish the context for potential toxicity. The specific digitalis glycoside medication being used will be assessed, with a focus on the dosage and duration of treatment. The clinician will verify the accuracy of the prescribed dosage and determine whether any recent changes or adjustments have been made to the medication regimen.
Reviewing the patient’s current medications is crucial to identify potential drug interactions that can potentiate digitalis toxicity. The clinician will inquire about any recent changes or additions to the medication regimen, particularly medications that interact with digitalis glycosides, such as quinidine, verapamil, amiodarone, and certain antibiotics. Electrolyte imbalances, particularly hypokalemia, can contribute to digitalis toxicity.
The clinician will assess whether the patient has a history of electrolyte abnormalities or is currently taking medications that may affect electrolyte balance. Symptoms such as gastrointestinal disturbances (nausea, vomiting, diarrhea), cardiovascular symptoms (palpitations, irregular heartbeat), neurological symptoms (confusion, dizziness, visual disturbances), or any other concerns that may be indicative of digitalis toxicity.
Physical Examination
Physical Examination
Bradycardia is a classic finding in digitalis toxicity due to its effect on slowing the heart rate. However, tachycardia or irregular heart rhythms may also be present, depending on the severity of toxicity and associated complications. In digitalis toxicity, findings may include irregular heart rhythms, extra heart sounds, or signs of congestive heart failure (such as crackles in the lungs or peripheral edema).
Auscultation may also reveal murmurs or other abnormalities associated with underlying heart conditions. In cases of digitalis toxicity, the patient may exhibit confusion, dizziness, or other signs of neurologic impairment. Visual disturbances, such as blurred vision or seeing halos around lights, may also be reported. The patient’s skin signs of pallor or cyanosis may indicate poor circulation or inadequate oxygenation. The presence of any rashes or allergic reactions to medications will also be noted.
Age group
Associated comorbidity
Associated activity
Acuity of presentation
Differential Diagnoses
Differential Diagnoses
Acute kidney injury
Calcium channel blocker toxicity
Beta-blocker toxicity
Hypercalcemia
Hypernatremia
Hyperkalemia
Hypoglycemia
Hyponatremia
Hypokalemia
Laboratory Studies
Imaging Studies
Procedures
Histologic Findings
Staging
Treatment Paradigm
The first step in managing digitalis toxicity is to stop or reduce the dose of digitalis glycosides to prevent further accumulation. The healthcare provider will determine the appropriate course of action based on the severity of toxicity and the patient’s circumstances. Supportive care is essential in managing digitalis toxicity. This may include monitoring vital signs, providing supplemental oxygen, and maintaining adequate hydration.
Correcting electrolyte imbalances, particularly potassium, and magnesium, is crucial, as these imbalances can contribute to toxicity. If necessary, intravenous administration of electrolytes may be required. Administration of activated charcoal may be considered if the patient presents within a few hours of an acute overdose. Activated charcoal can help bind to and prevent further absorption of the digitalis glycosides in the gastrointestinal tract. Medications may be administered to stabilize cardiac rhythm if the patient develops arrhythmias.
The choice of antiarrhythmic will depend on the specific arrhythmia and the patient’s clinical condition. Advanced cardiac life support (ACLS) protocols may be required in severe cases. Treatment with Digibind (digoxin immune fab) may be necessary in cases of severe or life-threatening digitalis toxicity. Digibind is an antidote that binds to and neutralizes the effects of digitalis glycosides, facilitating their removal from the body. It is typically reserved for severe toxicity or when other treatment measures have been ineffective.
Initial dose 1-2 g Intravenous infusion over 5 minutes
Following 1 g/hr drip in absence of digibind
The maximum therapeutic goal is to achieve 4.5 mEq/L
Future Trends
Media Gallary
References
News
Octopus-Inspired Patches Might Be A Pain-Free Alternative to Injections
Posted on
News
Feminist Cancer Care Approach Aims to Save 800,000 Lives Annually
Posted on
News
Breast Lifts Soar in Popularity Among Women
Posted on
News
Researchers Raise Concern on Alcohol Promotion in Sports
Digitalis toxicity, also known as digoxin toxicity, refers to an overdose or accumulation of digitalis glycosides in the body. Digitalis glycosides are a class of medications derived from the foxglove plant, most commonly represented by the drug digoxin. These medications treat various heart conditions, including congestive heart failure, atrial fibrillation, and atrial flutter.
Digitalis glycosides work by inhibiting the sodium-potassium ATPase pump in cardiac cells, leading to increased intracellular calcium levels. This results in enhanced myocardial contractility slowed heart rate, and improved cardiac output. However, an excessive amount of digitalis glycosides can lead to toxicity, as the therapeutic window for these medications is relatively narrow.
The prevalence of digitalis toxicity can vary depending on the population being studied and the specific criteria used for diagnosis. In general, digitalis toxicity is considered a relatively rare occurrence, especially when digitalis glycosides are used within the recommended therapeutic range. However, the incidence of toxicity increases with higher doses, older age, and the presence of underlying medical conditions that may affect drug metabolism or excretion.
Mortality rates associated with digitalis toxicity can also vary depending on the severity of the toxicity, promptness of medical intervention, and the overall health status of the affected individual. In mild to moderate toxicity cases, mortality rates are generally low, and most patients recover fully with appropriate treatment. However, severe cases of digitalis toxicity can be life-threatening and may lead to cardiac arrhythmias, cardiac arrest, or other complications that can increase mortality risk.
Digitalis glycosides inhibit the sodium-potassium ATPase pump, which maintains the intracellular and extracellular balance of sodium and potassium ions in cardiac cells. Inhibition of this pump leads to increased intracellular sodium levels, reduced extracellular potassium levels, and subsequent increase in intracellular calcium levels. The increase in intracellular calcium concentration results in enhanced myocardial contractility.
This positive inotropic effect is the desired therapeutic effect of digitalis glycosides in treating heart failure. However, excessive intracellular calcium levels can lead to dysregulation of cellular processes and contribute to toxicity. Elevated intracellular calcium levels can disturb the normal electrical conduction system of the heart. This can lead to cardiac arrhythmias, such as atrial and ventricular tachycardia, atrial fibrillation, or heart block. Arrhythmias can disrupt the heart’s normal rhythm and potentially lead to hemodynamic compromise.
Digitalis toxicity is often associated with hypokalemia and hypomagnesemia. These electrolyte imbalances can exacerbate the toxic effects of digitalis glycosides. Potassium and magnesium play a crucial role in maintaining the heart’s electrical stability, and their deficiencies can enhance the arrhythmogenic effects of digitalis glycosides. Digitalis toxicity can increase the automaticity of cardiac cells, leading to the generation of ectopic beats or abnormal pacemaker activity. This can contribute to the occurrence of arrhythmias.
Accidental overdoses or administration of higher-than-prescribed doses of digitalis glycosides can lead to toxicity. This can occur due to errors in medication preparation, administration, or miscommunication. The kidneys play a crucial role in the excretion of digitalis glycosides from the body. Impaired renal function, such as chronic kidney disease, can reduce the clearance of these medications, leading to their accumulation and an increased risk of toxicity.
Certain medications can interact with digitalis glycosides, altering their metabolism or potentiating their effects. This can lead to increased concentrations of digitalis glycosides in the blood and an elevated risk of toxicity. Medications such as quinidine, verapamil, amiodarone, macrolide antibiotics, and some antifungals are known to interact with digitalis glycosides. Older individuals, especially those with multiple medical conditions, are generally at a higher risk of developing digitalis toxicity.
Age-related changes in drug metabolism and clearance and other illnesses affecting organ function can contribute to an increased susceptibility to toxicity. Genetic variations in drug metabolism enzymes or transporters may influence the response to digitalis glycosides. Some individuals may have a heightened sensitivity or reduced ability to metabolize and eliminate these medications, increasing the risk of toxicity.
Clinical History
The clinician will inquire about any pre-existing heart conditions, such as congestive heart failure, atrial fibrillation, or atrial flutter, for which digitalis glycosides may have been prescribed. Understanding the indication for digitalis glycoside use helps establish the context for potential toxicity. The specific digitalis glycoside medication being used will be assessed, with a focus on the dosage and duration of treatment. The clinician will verify the accuracy of the prescribed dosage and determine whether any recent changes or adjustments have been made to the medication regimen.
Reviewing the patient’s current medications is crucial to identify potential drug interactions that can potentiate digitalis toxicity. The clinician will inquire about any recent changes or additions to the medication regimen, particularly medications that interact with digitalis glycosides, such as quinidine, verapamil, amiodarone, and certain antibiotics. Electrolyte imbalances, particularly hypokalemia, can contribute to digitalis toxicity.
The clinician will assess whether the patient has a history of electrolyte abnormalities or is currently taking medications that may affect electrolyte balance. Symptoms such as gastrointestinal disturbances (nausea, vomiting, diarrhea), cardiovascular symptoms (palpitations, irregular heartbeat), neurological symptoms (confusion, dizziness, visual disturbances), or any other concerns that may be indicative of digitalis toxicity.
Physical Examination
Bradycardia is a classic finding in digitalis toxicity due to its effect on slowing the heart rate. However, tachycardia or irregular heart rhythms may also be present, depending on the severity of toxicity and associated complications. In digitalis toxicity, findings may include irregular heart rhythms, extra heart sounds, or signs of congestive heart failure (such as crackles in the lungs or peripheral edema).
Auscultation may also reveal murmurs or other abnormalities associated with underlying heart conditions. In cases of digitalis toxicity, the patient may exhibit confusion, dizziness, or other signs of neurologic impairment. Visual disturbances, such as blurred vision or seeing halos around lights, may also be reported. The patient’s skin signs of pallor or cyanosis may indicate poor circulation or inadequate oxygenation. The presence of any rashes or allergic reactions to medications will also be noted.
Differential Diagnoses
Acute kidney injury
Calcium channel blocker toxicity
Beta-blocker toxicity
Hypercalcemia
Hypernatremia
Hyperkalemia
Hypoglycemia
Hyponatremia
Hypokalemia
The first step in managing digitalis toxicity is to stop or reduce the dose of digitalis glycosides to prevent further accumulation. The healthcare provider will determine the appropriate course of action based on the severity of toxicity and the patient’s circumstances. Supportive care is essential in managing digitalis toxicity. This may include monitoring vital signs, providing supplemental oxygen, and maintaining adequate hydration.
Correcting electrolyte imbalances, particularly potassium, and magnesium, is crucial, as these imbalances can contribute to toxicity. If necessary, intravenous administration of electrolytes may be required. Administration of activated charcoal may be considered if the patient presents within a few hours of an acute overdose. Activated charcoal can help bind to and prevent further absorption of the digitalis glycosides in the gastrointestinal tract. Medications may be administered to stabilize cardiac rhythm if the patient develops arrhythmias.
The choice of antiarrhythmic will depend on the specific arrhythmia and the patient’s clinical condition. Advanced cardiac life support (ACLS) protocols may be required in severe cases. Treatment with Digibind (digoxin immune fab) may be necessary in cases of severe or life-threatening digitalis toxicity. Digibind is an antidote that binds to and neutralizes the effects of digitalis glycosides, facilitating their removal from the body. It is typically reserved for severe toxicity or when other treatment measures have been ineffective.
Initial dose 1-2 g Intravenous infusion over 5 minutes
Following 1 g/hr drip in absence of digibind
The maximum therapeutic goal is to achieve 4.5 mEq/L
medtigo
Digitalis toxicity
Updated :
August 30, 2023
Digitalis toxicity, also known as digoxin toxicity, refers to an overdose or accumulation of digitalis glycosides in the body. Digitalis glycosides are a class of medications derived from the foxglove plant, most commonly represented by the drug digoxin. These medications treat various heart conditions, including congestive heart failure, atrial fibrillation, and atrial flutter.
Digitalis glycosides work by inhibiting the sodium-potassium ATPase pump in cardiac cells, leading to increased intracellular calcium levels. This results in enhanced myocardial contractility slowed heart rate, and improved cardiac output. However, an excessive amount of digitalis glycosides can lead to toxicity, as the therapeutic window for these medications is relatively narrow.
The prevalence of digitalis toxicity can vary depending on the population being studied and the specific criteria used for diagnosis. In general, digitalis toxicity is considered a relatively rare occurrence, especially when digitalis glycosides are used within the recommended therapeutic range. However, the incidence of toxicity increases with higher doses, older age, and the presence of underlying medical conditions that may affect drug metabolism or excretion.
Mortality rates associated with digitalis toxicity can also vary depending on the severity of the toxicity, promptness of medical intervention, and the overall health status of the affected individual. In mild to moderate toxicity cases, mortality rates are generally low, and most patients recover fully with appropriate treatment. However, severe cases of digitalis toxicity can be life-threatening and may lead to cardiac arrhythmias, cardiac arrest, or other complications that can increase mortality risk.
Digitalis glycosides inhibit the sodium-potassium ATPase pump, which maintains the intracellular and extracellular balance of sodium and potassium ions in cardiac cells. Inhibition of this pump leads to increased intracellular sodium levels, reduced extracellular potassium levels, and subsequent increase in intracellular calcium levels. The increase in intracellular calcium concentration results in enhanced myocardial contractility.
This positive inotropic effect is the desired therapeutic effect of digitalis glycosides in treating heart failure. However, excessive intracellular calcium levels can lead to dysregulation of cellular processes and contribute to toxicity. Elevated intracellular calcium levels can disturb the normal electrical conduction system of the heart. This can lead to cardiac arrhythmias, such as atrial and ventricular tachycardia, atrial fibrillation, or heart block. Arrhythmias can disrupt the heart’s normal rhythm and potentially lead to hemodynamic compromise.
Digitalis toxicity is often associated with hypokalemia and hypomagnesemia. These electrolyte imbalances can exacerbate the toxic effects of digitalis glycosides. Potassium and magnesium play a crucial role in maintaining the heart’s electrical stability, and their deficiencies can enhance the arrhythmogenic effects of digitalis glycosides. Digitalis toxicity can increase the automaticity of cardiac cells, leading to the generation of ectopic beats or abnormal pacemaker activity. This can contribute to the occurrence of arrhythmias.
Accidental overdoses or administration of higher-than-prescribed doses of digitalis glycosides can lead to toxicity. This can occur due to errors in medication preparation, administration, or miscommunication. The kidneys play a crucial role in the excretion of digitalis glycosides from the body. Impaired renal function, such as chronic kidney disease, can reduce the clearance of these medications, leading to their accumulation and an increased risk of toxicity.
Certain medications can interact with digitalis glycosides, altering their metabolism or potentiating their effects. This can lead to increased concentrations of digitalis glycosides in the blood and an elevated risk of toxicity. Medications such as quinidine, verapamil, amiodarone, macrolide antibiotics, and some antifungals are known to interact with digitalis glycosides. Older individuals, especially those with multiple medical conditions, are generally at a higher risk of developing digitalis toxicity.
Age-related changes in drug metabolism and clearance and other illnesses affecting organ function can contribute to an increased susceptibility to toxicity. Genetic variations in drug metabolism enzymes or transporters may influence the response to digitalis glycosides. Some individuals may have a heightened sensitivity or reduced ability to metabolize and eliminate these medications, increasing the risk of toxicity.
Clinical History
The clinician will inquire about any pre-existing heart conditions, such as congestive heart failure, atrial fibrillation, or atrial flutter, for which digitalis glycosides may have been prescribed. Understanding the indication for digitalis glycoside use helps establish the context for potential toxicity. The specific digitalis glycoside medication being used will be assessed, with a focus on the dosage and duration of treatment. The clinician will verify the accuracy of the prescribed dosage and determine whether any recent changes or adjustments have been made to the medication regimen.
Reviewing the patient’s current medications is crucial to identify potential drug interactions that can potentiate digitalis toxicity. The clinician will inquire about any recent changes or additions to the medication regimen, particularly medications that interact with digitalis glycosides, such as quinidine, verapamil, amiodarone, and certain antibiotics. Electrolyte imbalances, particularly hypokalemia, can contribute to digitalis toxicity.
The clinician will assess whether the patient has a history of electrolyte abnormalities or is currently taking medications that may affect electrolyte balance. Symptoms such as gastrointestinal disturbances (nausea, vomiting, diarrhea), cardiovascular symptoms (palpitations, irregular heartbeat), neurological symptoms (confusion, dizziness, visual disturbances), or any other concerns that may be indicative of digitalis toxicity.
Physical Examination
Bradycardia is a classic finding in digitalis toxicity due to its effect on slowing the heart rate. However, tachycardia or irregular heart rhythms may also be present, depending on the severity of toxicity and associated complications. In digitalis toxicity, findings may include irregular heart rhythms, extra heart sounds, or signs of congestive heart failure (such as crackles in the lungs or peripheral edema).
Auscultation may also reveal murmurs or other abnormalities associated with underlying heart conditions. In cases of digitalis toxicity, the patient may exhibit confusion, dizziness, or other signs of neurologic impairment. Visual disturbances, such as blurred vision or seeing halos around lights, may also be reported. The patient’s skin signs of pallor or cyanosis may indicate poor circulation or inadequate oxygenation. The presence of any rashes or allergic reactions to medications will also be noted.
Differential Diagnoses
Acute kidney injury
Calcium channel blocker toxicity
Beta-blocker toxicity
Hypercalcemia
Hypernatremia
Hyperkalemia
Hypoglycemia
Hyponatremia
Hypokalemia
The first step in managing digitalis toxicity is to stop or reduce the dose of digitalis glycosides to prevent further accumulation. The healthcare provider will determine the appropriate course of action based on the severity of toxicity and the patient’s circumstances. Supportive care is essential in managing digitalis toxicity. This may include monitoring vital signs, providing supplemental oxygen, and maintaining adequate hydration.
Correcting electrolyte imbalances, particularly potassium, and magnesium, is crucial, as these imbalances can contribute to toxicity. If necessary, intravenous administration of electrolytes may be required. Administration of activated charcoal may be considered if the patient presents within a few hours of an acute overdose. Activated charcoal can help bind to and prevent further absorption of the digitalis glycosides in the gastrointestinal tract. Medications may be administered to stabilize cardiac rhythm if the patient develops arrhythmias.
The choice of antiarrhythmic will depend on the specific arrhythmia and the patient’s clinical condition. Advanced cardiac life support (ACLS) protocols may be required in severe cases. Treatment with Digibind (digoxin immune fab) may be necessary in cases of severe or life-threatening digitalis toxicity. Digibind is an antidote that binds to and neutralizes the effects of digitalis glycosides, facilitating their removal from the body. It is typically reserved for severe toxicity or when other treatment measures have been ineffective.
Free CME credits
Both our subscription plans include Free CME/CPD AMA PRA Category 1 credits.
Digital Certificate PDF
On course completion, you will receive a full-sized presentation quality digital certificate.
medtigo Simulation
A dynamic medical simulation platform designed to train healthcare professionals and students to effectively run code situations through an immersive hands-on experience in a live, interactive 3D environment.
medtigo Points
medtigo points is our unique point redemption system created to award users for interacting on our site. These points can be redeemed for special discounts on the medtigo marketplace as well as towards the membership cost itself.
Community Forum post/reply = 5 points
*Redemption of points can occur only through the medtigo marketplace, courses, or simulation system. Money will not be credited to your bank account. 10 points = $1.
All Your Certificates in One Place
When you have your licenses, certificates and CMEs in one place, it's easier to track your career growth. You can easily share these with hospitals as well, using your medtigo app.
