Herb & supplement monograph

Swamp Milkweed Drug Interactions, Uses, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Swamp Milkweed interacts with medications. The heart of this page is the interaction list — every drug Swamp Milkweed is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Swamp Milkweed is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Reviewed by licensed pharmacists Sourced from Natural Medicines

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Swamp Milkweed Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Swamp Milkweed drug interaction is moderate for most people, largely because the plant contains natural compounds that act on the heart much like digoxin. None of the listed interactions are minor; nearly all are rated moderate, and a few major concerns involve heart medications.

Interactions deserving the most attention

The clearest concern is with digoxin, since swamp milkweed's heart-active compounds could add to its effects and raise the risk of toxicity, and this interaction has the strongest documentation. Quinine also stands out because it may slow the body's clearance of these compounds. Medicines that can lower potassium, including potassium-depleting diuretics, long-term corticosteroids, and overused stimulant laxatives, matter too, because low potassium makes these plant compounds more toxic. Certain antibiotics may also increase how much of them the body absorbs.

What the rest of the list means

Although the list of medications is long, nearly every entry traces back to one shared concern: the plant's digoxin-like compounds. Most interactions are rated only possible, meaning they rest on theory or laboratory findings rather than effects proven in people, so appearing on the list does not mean a combination has actually caused harm.

Check your medications against Swamp Milkweed

Based on HelloPharmacist’s Swamp Milkweed interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Swamp Milkweed

156 medications have a known interaction with Swamp Milkweed, graded by severity. Select any drug for the full evidence-based detail.

3 major interactions. These combinations can be clinically significant — best avoided, or used only with close professional supervision. Always check with your pharmacist before combining them with Swamp Milkweed.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Swamp Milkweed using our pharmacist-reviewed interaction data.

AI summaries are generated from our Swamp Milkweed interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Swamp Milkweed combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Swamp Milkweed affects

Every type of medication (drug category) Swamp Milkweed is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 7 drug categories Swamp Milkweed interacts with

Digoxin (lanoxin)QuinineCorticosteroidsDiuretic DrugsMacrolide AntibioticsStimulant LaxativesTetracycline Antibiotics

Digoxin (Lanoxin)

Theoretically, swamp milkweed might increase the risk of adverse effects and toxicity when taken with digoxin.
Swamp milkweed contains cardioactive steroids known as cardenolides that may have digitalis-like activity.

Likelihood Likely Evidence D

Quinine

Theoretically, quinine might increase the risk of toxicity from cardioactive steroids in swamp milkweed.
Swamp milkweed contains cardioactive steroids known as cardenolides that may have digitalis-like activity. Quinine may reduce the clearance of oral digoxin. Theoretically, concomitant use of quinine might reduce the clearance of cardenolides found in swamp milkweed and increase the risk of adverse effects.

Likelihood Probable Evidence D

Corticosteroids

Theoretically, taking swamp milkweed with prolonged corticosteroid therapy might increase the risk of toxicity.
Swamp milkweed contains cardioactive steroids known as cardenolides that may have digitalis-like activity. Long-term corticosteroid use can lead to potassium depletion and electrolyte imbalance, which can increase the risk of cardenolide toxicity.