Drug interactions
Tafenoquine + Varenicline
Severity: Moderate
Tafenoquine and Varenicline: 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
Varenicline is largely eliminated unchanged in urine via renal tubular secretion involving OCT2. Tafenoquine inhibits OCT2 and MATE in vitro, so it may raise varenicline concentrations and increase nausea, insomnia and abnormal dreams.
What this interaction means in plain words
Tafenoquine and Varenicline 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.
Tafenoquine belongs to Anti Parasitic; Varenicline belongs to Respiratory.
Why it happens
Tafenoquine inhibits renal OCT2 and MATE transporters, which reduces varenicline tubular secretion.
What to do
Monitor for varenicline adverse effects such as nausea and neuropsychiatric symptoms, and reduce the dose if poorly tolerated.
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 Varenicline
- Ethanol + Varenicline Moderate
- Trilaciclib + Varenicline Moderate
- Cimetidine + Varenicline Minor
- Erdafitinib + Varenicline Minor
- Ibuprofen / famotidine + Varenicline Minor
- Nicotine inhaled + Varenicline Minor
Other interactions of Tafenoquine
- Dofetilide + Tafenoquine Major
- Alogliptin-metformin + Tafenoquine Moderate
- Amantadine + Tafenoquine Moderate
- Amiloride + Tafenoquine Moderate
- Canagliflozin-metformin + Tafenoquine Moderate
- Cimetidine + Tafenoquine Moderate
Frequently asked questions
Can I take Tafenoquine with Varenicline?
MediHelp rates the interaction as moderate. Tafenoquine and Varenicline 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. Varenicline is largely eliminated unchanged in urine via renal tubular secretion involving OCT2. Tafenoquine inhibits OCT2 and MATE in vitro, so it may raise varenicline concentrations and increase nausea, insomnia and abnormal dreams.
How serious is the interaction between Tafenoquine and Varenicline?
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 for varenicline adverse effects such as nausea and neuropsychiatric symptoms, and reduce the dose if poorly tolerated.
What other medicines interact with Varenicline?
MediHelp also lists interactions of Varenicline with, for example, Ethanol, Trilaciclib, Cimetidine. The full list is on the Varenicline page.
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