Drug interactions
Cimetidine + Varenicline
Severity: Minor
Cimetidine and Varenicline: minor 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
Cimetidine can raise varenicline exposure modestly because both are handled by renal tubular secretion. The increase is small and is rarely clinically important in patients with normal kidney function.
What this interaction means in plain words
Cimetidine and Varenicline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cimetidine belongs to Gastrointestinal Tract; Varenicline belongs to Respiratory.
Why it happens
Cimetidine inhibits renal tubular cationic transport (OCT2) of varenicline, reducing its renal clearance.
What to do
No dose change is needed with normal renal function. In severe renal impairment, avoid the combination or monitor closely for nausea and other adverse effects of varenicline.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Varenicline
- Ethanol + Varenicline Moderate
- Tafenoquine + Varenicline Moderate
- Trilaciclib + Varenicline Moderate
- Erdafitinib + Varenicline Minor
- Ibuprofen / famotidine + Varenicline Minor
- Nicotine inhaled + Varenicline Minor
Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Frequently asked questions
Can I take Cimetidine with Varenicline?
MediHelp rates the interaction as minor. Cimetidine and Varenicline have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cimetidine can raise varenicline exposure modestly because both are handled by renal tubular secretion. The increase is small and is rarely clinically important in patients with normal kidney function.
How serious is the interaction between Cimetidine and Varenicline?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is needed with normal renal function. In severe renal impairment, avoid the combination or monitor closely for nausea and other adverse effects of varenicline.
What other medicines interact with Varenicline?
MediHelp also lists interactions of Varenicline with, for example, Ethanol, Tafenoquine, Trilaciclib. The full list is on the Varenicline page.
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