Drug interactions
Modafinil + Phentermine
Severity: Moderate
Modafinil and Phentermine: 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
Both agents are stimulants, so together they may amplify nervousness, insomnia, palpitations and blood pressure elevation. Risk is greater in patients with cardiovascular disease.
What this interaction means in plain words
Modafinil and Phentermine 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.
Modafinil belongs to Central Nervous System; Phentermine belongs to Central Nervous System.
Why it happens
Additive CNS and sympathomimetic stimulation.
What to do
Monitor blood pressure, heart rate and sleep; reduce a dose or stop one drug if stimulant effects emerge.
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 Modafinil
Other interactions of Phentermine
- Isocarboxazid + Phentermine Contraindicated
- Linezolid + Phentermine Contraindicated
- Phenelzine + Phentermine Contraindicated
- Phentermine + Procarbazine Contraindicated
- Phentermine + Rasagiline Contraindicated
- Phentermine + Selegiline Contraindicated
Frequently asked questions
Can I take Modafinil with Phentermine?
MediHelp rates the interaction as moderate. Modafinil and Phentermine 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. Both agents are stimulants, so together they may amplify nervousness, insomnia, palpitations and blood pressure elevation. Risk is greater in patients with cardiovascular disease.
How serious is the interaction between Modafinil and Phentermine?
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 blood pressure, heart rate and sleep; reduce a dose or stop one drug if stimulant effects emerge.
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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