Drug interactions
Caffeine + Olanzapine
Severity: Minor
Caffeine and Olanzapine: 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
Caffeine is metabolised by CYP1A2, the main enzyme for olanzapine, so the two compete for clearance. Heavy caffeine intake may modestly reduce olanzapine sedation, while abrupt changes in caffeine intake can shift olanzapine exposure slightly. The effect is usually small.
What this interaction means in plain words
Caffeine and Olanzapine 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; Olanzapine belongs to Central Nervous System.
Why it happens
Competition at CYP1A2 and opposing CNS effects: caffeine is a stimulant and olanzapine a sedating antipsychotic.
What to do
No dose change is normally required; encourage a stable daily caffeine intake. If clinical response changes after a large shift in caffeine consumption, reassess olanzapine dosing.
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 Olanzapine
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 Olanzapine?
MediHelp rates the interaction as minor. Caffeine and Olanzapine 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 is metabolised by CYP1A2, the main enzyme for olanzapine, so the two compete for clearance. Heavy caffeine intake may modestly reduce olanzapine sedation, while abrupt changes in caffeine intake can shift olanzapine exposure slightly. The effect is usually small.
How serious is the interaction between Caffeine and Olanzapine?
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 normally required; encourage a stable daily caffeine intake. If clinical response changes after a large shift in caffeine consumption, reassess olanzapine dosing.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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