Digoxin with Calcium Interaction Details

Brand Names Associated with Digoxin

Brand Names Associated with Calcium

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Jan 08, 2024

Interaction Effect

A serious risk of arrhythmia and cardiovascular collapse

Interaction Summary

Calcium, particularly if administered rapidly by the intravenous (IV) route, may produce serious arrhythmias in digitalized patients. The similar actions of digitalis glycosides and calcium are documented, and deaths have occurred during simultaneous administration . Therefore, IV injection of calcium compounds should be used cautiously in patients receiving digoxin or digitalis-like preparations and only if clearly indicated . If concurrent use of IV calcium compounds is warranted in the digitalized patient, slow IV administration with close patient monitoring is recommended. Due to the risk of developing hypercalcemia and subsequent cardiac arrhythmias, concurrent administration of oral calcium acetate is not recommended in patients receiving digitalis .

Severity

Major

Onset

Rapid

Evidence

Probable

How To Manage Interaction

Calcium, especially if given by rapid, intravenous (IV) injection in patients receiving digoxin may produce serious arrhythmias, and cases have been reported following bolus IV calcium administrations . Use of IV calcium compounds in digitalized patients is recommended only if it is clearly indicated . Use caution if concurrent use of IV calcium is warranted, administer slowly over several hours, and monitor patients closely. Due to the risk of developing hypercalcemia and subsequent cardiac arrhythmias, coadministration of oral calcium acetate is not recommended in patients receiving digitalis .

Mechanism Of Interaction

Additive or synergistic cardiac effects

Literature Reports

A) The relationship between calcium and digitalis is documented in animal studies, though controversy does exist over whether it is synergistic, additive or if a relationship exists at all . Methods of evaluation have also been quite diverse. Two case reports have described serious interactions with intravenous (IV) calcium use in digitalized patients. The first case was a 32 year-old white female with no mention of heart disease who underwent a cholecystectomy. She was given a total of 15 ml of Digalen(R) over six days for tachycardia, low blood pressure and extrasystoles. The tachycardia remained persistent and 10 mL calcium gluconate was given intravenously. Two minutes later the patient suffered cardiac and respiratory arrest and died. The second patient was a 55 year-old white male with admitting diagnosis of multiple myeloma or hyperparathyroidism. Thyroid surgery was performed and 8.5 ml Digalen(R) was given over 20 hours (no stated reason). Two days later a fine tremor developed, 10 mL of calcium chloride was given intravenously and a few minutes later the patient died of cardiovascular collapse .

B) A retrospective study of 112 cases with possible digitalis toxicity evaluated 40 cases based on defined criteria of digitalis toxicity. Two cases of toxicity were thought to be due to the administration of calcium gluconate intravenously. Both patients were digitalized, one on lanatoside C, the other on digoxin, and both were hypocalcemic. One patient died 10 minutes after receiving the calcium, the other received calcium for three days (rate not specified) and developed apparent digitalis toxicity, but did not expire .

Digoxin Overview

• Digoxin is used to treat heart failure and abnormal heart rhythms (arrhythmias). It helps the heart work better and it helps control your heart rate.

Calcium Overview

• Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not enough. Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach. It is available with or without a prescription.

• This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.