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Drug interactions

Digoxin + Saquinavir

Severity: Major

Digoxin and Saquinavir: major interaction.

Last updated Sources: US FDA label

For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.

Summary

Saquinavir, usually boosted with ritonavir, can raise digoxin concentrations and the risk of digoxin toxicity. Digoxin has a narrow therapeutic index.

What this interaction means in plain words

Digoxin and Saquinavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Evidence level: Moderate

Why it happens

Saquinavir inhibits P-glycoprotein, decreasing digoxin renal and intestinal efflux.

What to do

Start with a lower digoxin dose and monitor digoxin concentrations and ECG closely; adjust to response.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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References

Frequently asked questions

Can I take Digoxin with Saquinavir?

MediHelp rates the interaction as major. Digoxin and Saquinavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Saquinavir, usually boosted with ritonavir, can raise digoxin concentrations and the risk of digoxin toxicity. Digoxin has a narrow therapeutic index.

How serious is the interaction between Digoxin and Saquinavir?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with a lower digoxin dose and monitor digoxin concentrations and ECG closely; adjust to response.

What other medicines interact with Digoxin?

MediHelp also lists interactions of Digoxin with, for example, Lily of the valley, Squill, Adagrasib. The full list is on the Digoxin page.

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