Drug interactions
Flecainide + Sodium bicarbonate
Severity: Moderate
Flecainide and Sodium bicarbonate: moderate interaction.
Last updated
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
Alkalinizing the urine reduces renal elimination of flecainide, which is a weak base, so plasma levels and half-life may increase. This can lead to flecainide toxicity such as conduction block and arrhythmias.
What this interaction means in plain words
Flecainide and Sodium bicarbonate can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Flecainide belongs to Cardiovascular; Sodium bicarbonate belongs to Gastrointestinal Tract.
Why it happens
Alkaline urine increases passive tubular reabsorption of flecainide, decreasing renal clearance.
What to do
Monitor ECG and flecainide concentrations in patients receiving regular or high-dose bicarbonate. Adjust flecainide dose if urine alkalinization is sustained.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Flecainide
- Flecainide + Nirmatrelvir Contraindicated
- Flecainide + Nirmatrelvir / ritonavir Contraindicated
- Flecainide + Pimozide Contraindicated
- Flecainide + Ritonavir Contraindicated
- Flecainide + Thioridazine Contraindicated
- Flecainide + Tipranavir Contraindicated
Other interactions of Sodium bicarbonate
- Acetylsalicylic acid + Sodium bicarbonate Moderate
- Alendronate + Sodium bicarbonate Moderate
- Amantadine + Sodium bicarbonate Moderate
- Carbonyl iron + Sodium bicarbonate Moderate
- Cefditoren + Sodium bicarbonate Moderate
- Cefpodoxime + Sodium bicarbonate Moderate
Frequently asked questions
Can I take Flecainide with Sodium bicarbonate?
MediHelp rates the interaction as moderate. Flecainide and Sodium bicarbonate can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Alkalinizing the urine reduces renal elimination of flecainide, which is a weak base, so plasma levels and half-life may increase. This can lead to flecainide toxicity such as conduction block and arrhythmias.
How serious is the interaction between Flecainide and Sodium bicarbonate?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor ECG and flecainide concentrations in patients receiving regular or high-dose bicarbonate. Adjust flecainide dose if urine alkalinization is sustained.
What other medicines interact with Flecainide?
MediHelp also lists interactions of Flecainide with, for example, Nirmatrelvir, Nirmatrelvir / ritonavir, Pimozide. The full list is on the Flecainide page.
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