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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Nitrate Vasodilator [EPC]
Digitalis is a class of cardiac medications, including digoxin, derived from the foxglove plant. It is primarily used to treat heart failure and atrial fibrillation by increasing the force of heart contractions and regulating heart rhythm.
Name
Digitalis
Raw Name
DIGITALIS
Category
Nitrate Vasodilator [EPC]
Drug Count
63
Variant Count
90
Last Verified
February 17, 2026
About Digitalis
Digitalis is a class of cardiac medications, including digoxin, derived from the foxglove plant. It is primarily used to treat heart failure and atrial fibrillation by increasing the force of heart contractions and regulating heart rhythm.
Detailed information about Digitalis
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Digitalis.
At the molecular level, digitalis works by inhibiting the sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) pump, primarily in the myocardium (heart muscle). By inhibiting this enzyme, digitalis increases the concentration of sodium within the heart cells. This rise in intracellular sodium subsequently slows down the sodium-calcium exchanger, leading to an accumulation of intracellular calcium. Because calcium is the primary trigger for muscle contraction, the increased availability of calcium ions results in a more forceful contraction of the heart muscle, a property known as positive inotropy.
Furthermore, digitalis exerts a potent effect on the autonomic nervous system. It increases vagal tone (parasympathetic activity), which slows the conduction of electrical impulses through the atrioventricular (AV) node. This action, known as negative chronotropy, is vital for managing rapid heart rates in conditions like atrial fibrillation. By slowing the heart rate and increasing the strength of each beat, digitalis improves cardiac output and reduces the symptoms of heart failure. Your healthcare provider will determine if this mechanism is appropriate for your specific cardiac profile.
Understanding how the body processes digitalis is critical due to its narrow therapeutic index (the small margin between a safe dose and a toxic dose).
Digitalis is FDA-approved for the following indications:
Off-label uses may include the management of certain supraventricular tachycardias (SVT) under strict specialist supervision. Only your healthcare provider can determine if Digitalis is right for your specific condition.
Digitalis (as Digoxin) is available in several dosage forms to accommodate different patient needs:
Dosage for Digitalis must be highly individualized based on the patient's age, lean body weight, and renal function. Healthcare providers often use a 'loading dose' (digitalization) to achieve therapeutic levels quickly, followed by a 'maintenance dose.'
Digitalis is used in pediatric patients, but dosing is extremely complex and must be calculated by a specialist based on the child’s age and weight in kilograms.
> Warning: Pediatric digitalis liquid must be measured with the specific dropper provided with the medication to avoid life-threatening dosing errors.
Because digitalis is primarily cleared by the kidneys, patients with renal impairment are at a significantly higher risk of toxicity. For patients with a Creatinine Clearance (CrCl) below 50 mL/min, the dose is typically reduced by 50%, or the frequency is changed to every other day. Routine serum digoxin level monitoring is mandatory in these patients.
Generally, no dose adjustment is required for patients with liver disease alone, as the drug is primarily excreted renally. However, if hepatic impairment is accompanied by renal issues, extreme caution is necessary.
Geriatric patients often have a lower lean body mass and naturally declining kidney function. Healthcare providers typically start elderly patients on the lowest possible dose (e.g., 62.5 mcg or 125 mcg every other day) and monitor closely for signs of confusion or visual changes.
If you miss a dose, take it as soon as you remember. However, if it is within 12 hours of your next scheduled dose, skip the missed dose and return to your regular schedule. Never double the dose to catch up, as this can lead to acute toxicity.
Digitalis overdose is a medical emergency. Signs include severe nausea, vomiting, heart palpitations, confusion, and seeing yellow or green 'halos' around lights. If an overdose is suspected, contact emergency services or a poison control center immediately. Treatment may involve the administration of Digoxin Immune Fab (Digibind), which is an antidote that binds to the drug and neutralizes its effects.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose without medical guidance.
While many patients tolerate digitalis well at therapeutic levels, side effects are common, especially as the dose approaches the upper limit of the therapeutic range. Common reactions include:
> Warning: Stop taking Digitalis and call your doctor immediately if you experience any of these symptoms of digitalis toxicity:
Prolonged use of digitalis requires ongoing monitoring. Long-term effects can include chronic electrolyte imbalances if used alongside diuretics. There is also evidence that long-term digitalis use may influence bone density or hormonal balance in some patients, though these effects are still being studied. The primary long-term risk remains the gradual accumulation of the drug in tissues, leading to 'creeping' toxicity even if the daily dose remains unchanged.
No FDA black box warnings currently exist for Digitalis (Digoxin). However, the FDA emphasizes that digitalis should not be used for weight loss or the treatment of obesity. Using digitalis for these purposes is dangerous and can lead to life-threatening heart rhythm problems or death. It is strictly indicated for heart failure and rhythm control.
Report any unusual symptoms to your healthcare provider. Even mild nausea should be reported, as it may be an early warning sign of toxicity.
Digitalis has a narrow therapeutic index, meaning the difference between a dose that helps and a dose that harms is very small. Patients must undergo regular blood tests to measure the concentration of the drug in their system. The typical therapeutic range is 0.5 to 2.0 ng/mL, though for heart failure, many doctors prefer a lower range of 0.5 to 0.9 ng/mL.
Patients taking Digitalis require consistent clinical oversight:
Digitalis may cause dizziness or visual disturbances (like blurred vision). Do not drive or operate heavy machinery until you know how this medication affects you. If you notice any changes in your vision, contact your doctor immediately.
While there is no direct chemical interaction between alcohol and digitalis, alcohol can cause dehydration and electrolyte shifts that may increase the risk of digitalis toxicity. Excessive alcohol use can also worsen heart failure symptoms. It is generally advised to limit alcohol intake.
Do not stop taking Digitalis suddenly without consulting your doctor. Sudden discontinuation can lead to a rapid worsening of heart failure symptoms or an uncontrolled increase in heart rate (tachycardia) in patients with atrial fibrillation.
> Important: Discuss all your medical conditions, especially kidney disease and thyroid problems, with your healthcare provider before starting Digitalis.
Digitalis should not be used with certain medications due to the risk of fatal heart rhythms:
Digitalis can interfere with the results of certain lab tests, including those for endogenous digoxin-like immunoreactive substances (DLIS), which can cause false-positive results in digitalis blood tests in certain conditions like pregnancy or liver disease.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, as digitalis has more interactions than almost any other cardiovascular drug.
Digitalis must NEVER be used in the following circumstances:
These conditions require a careful risk-benefit analysis by a physician:
Patients who are allergic to one form of digitalis (e.g., digoxin) are likely to be allergic to others (e.g., digitoxin or the foxglove plant itself). Always inform your healthcare provider of any plant or medication allergies.
> Important: Your healthcare provider will evaluate your complete medical history, including an ECG and blood work, before prescribing Digitalis.
Digitalis is classified as FDA Pregnancy Category C. This means that animal studies have shown an adverse effect on the fetus, but there are no adequate and well-controlled studies in humans. However, digitalis has been used for decades in pregnant women with heart failure or supraventricular arrhythmias without a clear pattern of birth defects. It is known to cross the placenta. In some cases, digitalis is even given to the mother to treat an abnormally fast heart rate in the fetus. Its use during pregnancy should only occur if the potential benefit justifies the potential risk to the fetus.
Digitalis is excreted into breast milk in very small amounts. The concentration in breast milk is typically lower than in the mother's blood. According to the American Academy of Pediatrics, digitalis is generally considered compatible with breastfeeding. However, nursing infants should be monitored for any signs of toxicity, such as poor feeding or unusual lethargy.
Digitalis is approved for use in children of all ages, including newborns. It is frequently used to treat congenital heart defects and pediatric heart failure. However, children are at a higher risk of accidental overdose. The margin of safety is very narrow, and dosing must be meticulously calculated by a pediatric cardiologist. Parents must be educated on the signs of pediatric toxicity, which often present as nausea or a refusal to eat.
Patients over the age of 65 are at the highest risk for digitalis-related complications. Age-related declines in kidney function mean the drug stays in the body much longer. Furthermore, elderly patients are more likely to be taking multiple other medications (polypharmacy), increasing the risk of interactions. Confusion and visual changes are more common in this age group and may be mistaken for 'normal aging' rather than medication toxicity.
In patients with chronic kidney disease (CKD), the half-life of digitalis can increase from 36 hours to over 100 hours. For those on dialysis, digitalis is not significantly removed by the procedure. Dosing in these patients is typically 'low and slow,' often starting at 62.5 mcg every other day with frequent blood level monitoring.
While the liver is not the primary route of elimination, severe liver disease (Child-Pugh Class C) can alter the volume of distribution and protein binding of the drug. No specific dose adjustment is usually required, but clinical monitoring is advised.
> Important: Special populations require individualized medical assessment and more frequent lab monitoring.
Digitalis exerts its effects through two primary pathways: mechanical and electrical.
| Parameter | Value |
|---|---|
| Bioavailability | 60%–80% (Tablets), 90%+ (Capsules) |
| Protein Binding | 20% to 25% (primarily to Albumin) |
| Half-life | 36 to 48 hours (Normal Renal Function) |
| Tmax | 1 to 3 hours |
| Metabolism | Minimal (Gut bacteria and non-CYP hepatic) |
| Excretion | Renal (50%–70% unchanged) |
Digitalis is the prototype of the Cardiac Glycoside class. While the prompt mentions classifications like Nitrate Vasodilator [EPC] and Adrenergic Agonist [EPC], these are secondary or regulatory categorizations. Its primary clinical identity is as a cardiotonic agent.
Medications containing this ingredient
Common questions about Digitalis
Digitalis is primarily used to treat two major heart conditions: congestive heart failure and certain types of irregular heartbeats, specifically atrial fibrillation and atrial flutter. In heart failure, it helps the heart pump more efficiently by increasing the strength of the heart muscle contractions. For heart rhythm issues, it works by slowing down the electrical signals that start in the upper chambers of the heart, which helps the lower chambers maintain a steadier rhythm. It is usually prescribed when other medications, like beta-blockers or ACE inhibitors, are not providing enough symptom relief. Your healthcare provider will determine the appropriate use based on your specific cardiac diagnosis.
The most common side effects of digitalis include nausea, vomiting, loss of appetite, and a general feeling of tiredness or weakness. Some patients may also experience mild headaches or dizziness when they first start the medication. It is important to distinguish these common side effects from signs of toxicity, which can be much more serious. If you notice persistent stomach issues or changes in your vision, such as seeing yellow or green halos, you should contact your doctor immediately. Most mild side effects will be monitored by your physician during your regular check-ups.
While there is no direct chemical interaction between alcohol and digitalis, it is generally recommended to limit or avoid alcohol consumption. Alcohol can act as a diuretic, leading to dehydration and shifts in your body's electrolyte levels, such as potassium and magnesium. Because low potassium levels significantly increase the risk of digitalis toxicity, drinking alcohol can indirectly make the medication dangerous. Additionally, alcohol can weaken the heart muscle, which counteracts the benefits of taking digitalis for heart failure. Always discuss your alcohol consumption habits with your cardiologist.
Digitalis is classified as Pregnancy Category C, meaning it should only be used if the potential benefits outweigh the risks to the fetus. It has been used for many years to treat heart conditions in pregnant women, and in some cases, it is even used to treat a fast heart rate in the unborn baby. While it does cross the placenta, it is not generally associated with a high risk of birth defects. However, pregnancy can change how your kidneys process the drug, so your doctor will need to monitor your blood levels more frequently. Always inform your obstetrician and cardiologist if you are pregnant or planning to become pregnant.
The time it takes for digitalis to work depends on how it is administered and whether a 'loading dose' was used. If taken orally, you may begin to feel the effects within 1 to 2 hours, but it can take several days of consistent dosing to reach a 'steady state' in your bloodstream where the full benefits are felt. If given intravenously in a hospital setting, the effects on the heart rate can begin within 5 to 30 minutes. For chronic conditions like heart failure, it may take several weeks of treatment before you notice a significant improvement in your ability to exercise or a reduction in shortness of breath. Your doctor will use blood tests to ensure the drug is at an effective level.
No, you should never stop taking digitalis suddenly without your doctor's explicit instructions. Stopping the medication abruptly can cause a rapid return of heart failure symptoms, such as severe shortness of breath and fluid buildup. For patients taking it for atrial fibrillation, stopping the drug can cause the heart rate to become dangerously fast and irregular very quickly. If your doctor decides you no longer need the medication, they will usually provide a plan to slowly taper the dose. Always ensure you have enough refills so that you do not miss doses unexpectedly.
If you miss a dose of digitalis, take it as soon as you remember, provided it is within 12 hours of the original scheduled time. If more than 12 hours have passed, you should skip the missed dose and take your next dose at the regular time. Do not take two doses at once to make up for a missed one, as this significantly increases the risk of toxicity. It is helpful to use a pill organizer or a phone alarm to ensure you take the medication consistently. If you miss more than two doses in a row, contact your healthcare provider for specific instructions.
Digitalis itself does not typically cause weight gain; in fact, it is used to treat heart failure, which often causes weight gain due to fluid retention. If the medication is working effectively, you may actually notice weight loss as your heart pumps better and your body gets rid of excess fluid. However, if you notice a sudden, rapid weight gain (such as 2-3 pounds in a single day), this may be a sign that your heart failure is worsening, not a side effect of the drug. You should report any sudden changes in weight to your doctor immediately. Always weigh yourself at the same time each morning for the most accurate tracking.
Digitalis has many significant interactions with other medications, so it must be managed carefully. It is frequently taken alongside other heart medications like ACE inhibitors and certain diuretics, but some drugs can dangerously increase its levels. For example, common medications like amiodarone, verapamil, and even some antibiotics can make digitalis levels rise to toxic levels. Even over-the-counter antacids and herbal supplements like St. John's Wort can affect how much digitalis your body absorbs. You must provide your doctor and pharmacist with a complete list of every medication and supplement you take to prevent dangerous interactions.
Yes, digitalis is widely available as a generic medication, most commonly under the name digoxin. Generic versions are typically much more affordable than brand-name versions like Lanoxin. While generic medications are required by the FDA to be bioequivalent to the brand name, some cardiologists prefer that patients stay on the same manufacturer's version once a stable blood level is reached. This is because even very small variations in how a tablet dissolves can affect the blood levels of this specific drug. If your pharmacy changes your generic manufacturer, your doctor may want to check your blood levels again to ensure they remain in the therapeutic range.