Digoxin with Squill Interaction Details
Brand Names Associated with Digoxin
- Cardoxin®
- Digitek®
- Digoxin
- Lanoxicaps®
- Lanoxin®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jan 08, 2024
Interaction Effect
Increased risk of digoxin toxicity
Interaction Summary
A case of death likely due to cardiac glycoside toxicity following squill ingestion has been reported. Both squill and digitalis, the source of digoxin, are known to contain cardiac glycosides known as cardenolides . Squill contains proscillaridin A as its principal cardiac glycoside . At this time, squill is not widely available in the United States.
Severity
Major
Onset
Rapid
Evidence
Theoretical
How To Manage Interaction
Concomitant use is contraindicated due to the chemical similarity between squill and digoxin. Patients with unexplained signs and symptoms of digoxin toxicity (e.g., nausea, vomiting, abnormal vision, cardiac arrhythmias, unexplained hyperkalemia) in the absence of increased dosage should be questioned about squill intake. A digoxin level may confirm the diagnosis, but may not quantify the severity. Treatment with digoxin-specific Fab (dsFab) antibody fragments has been successful in toxic ingestion of other cardiac glycoside-containing plants, but the efficacy of dsFab is unknown in cases of squill ingestion.
Mechanism Of Interaction
Additive cardiac glycoside activity
Literature Reports
A) A 55 year-old female developed nausea, vomiting, and seizures following ingestion of squill for arthritis. On admission to the hospital 2 hours after ingestion, blood pressure was 110/70 mmHg, pulse was 56 beats/minute, serum potassium was 5.9 millimoles/liter (mmol/L), and a digoxin level was 1.59 nanograms/milliliter (ng/mL). Gastric lavage was performed and activated charcoal 50 grams was administered. Nine hours after ingestion, electrocardiogram showed complete atrioventricular block, and the patient had lost consciousness. Atropine was ineffective, and a temporary cardiac pacemaker was applied at 60 beats/minute. Twenty-four hours after ingestion, ventricular tachycardia occurred and serum potassium was 6.2 mmol/L. Lidocaine injections were ineffective and ventricular fibrillation occurred which was unresponsive to direct-current cardioversion and cardiopulmonary resuscitation. Death occurred 30 hours after ingestion. The patient's medical history included hypothyroidism treated with thyroxine; a TSH level one week prior to squill ingestion was 9.4 milli-international units/milliliter (mIU/mL) (normal 0.25 to 4.3 mIU/mL) and T3 was 61 nanograms/deciliter (ng/dL) (normal 86 to 187 ng/dL). Hypothyroidism may be a risk factor for digoxin toxicity .
Digoxin Overview
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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.
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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.
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Information for our drug interactions is compiled from several drug compendia, including:
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.