Drug interactions
Caffeine + Modafinil
Severity: Minor
Caffeine and Modafinil: 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
Both agents are CNS stimulants, so combined use may produce additive effects such as insomnia, anxiety, tremor, palpitations and raised blood pressure. Modafinil does not markedly change caffeine kinetics, but large caffeine intake may worsen adverse effects.
What this interaction means in plain words
Caffeine and Modafinil 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; Modafinil belongs to Central Nervous System.
Why it happens
Additive CNS stimulation through different pathways (adenosine antagonism with caffeine, dopamine reuptake inhibition with modafinil).
What to do
Advise moderating caffeine intake, especially in the afternoon, and monitor for insomnia, nervousness and tachycardia.
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 Modafinil
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 Modafinil?
MediHelp rates the interaction as minor. Caffeine and Modafinil have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Both agents are CNS stimulants, so combined use may produce additive effects such as insomnia, anxiety, tremor, palpitations and raised blood pressure. Modafinil does not markedly change caffeine kinetics, but large caffeine intake may worsen adverse effects.
How serious is the interaction between Caffeine and Modafinil?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise moderating caffeine intake, especially in the afternoon, and monitor for insomnia, nervousness and tachycardia.
What other medicines interact with Modafinil?
MediHelp also lists interactions of Modafinil with, for example, Lenacapavir, Leniolisib, Lorlatinib. The full list is on the Modafinil page.
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