Drug interactions
Caffeine + Ketoconazole
Severity: Minor
Caffeine and Ketoconazole: 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
Ketoconazole may slightly reduce caffeine clearance, increasing stimulant effects such as insomnia, tremor and palpitations in sensitive people.
What this interaction means in plain words
Caffeine and Ketoconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Caffeine belongs to Miscellaneous; Ketoconazole belongs to Anti Fungals.
Why it happens
Caffeine is mainly cleared by CYP1A2, and ketoconazole may have weak inhibitory effects.
What to do
No action is generally needed; advise limiting caffeine if jitteriness or palpitations occur.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Caffeine
- Caffeine + Ephedrine Major
- Caffeine + Fezolinetant Major
- Caffeine + Methylenedioxymethamphetamine Major
- Caffeine + Selegiline transdermal Major
- Adenosine + Caffeine Moderate
- Benzphetamine + Caffeine Moderate
Frequently asked questions
Can I take Caffeine with Ketoconazole?
MediHelp rates the interaction as minor. Caffeine and Ketoconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Ketoconazole may slightly reduce caffeine clearance, increasing stimulant effects such as insomnia, tremor and palpitations in sensitive people.
How serious is the interaction between Caffeine and Ketoconazole?
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 action is generally needed; advise limiting caffeine if jitteriness or palpitations occur.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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