Drug interactions
Dextroamphetamine + Phenobarbital
Severity: Moderate
Dextroamphetamine and Phenobarbital: 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
Phenobarbital sedates while dextroamphetamine stimulates, so the net effect is unpredictable and sedation may be masked. Phenobarbital also induces hepatic enzymes, which may lower the exposure of some co-administered drugs.
What this interaction means in plain words
Dextroamphetamine and Phenobarbital 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.
Why it happens
Opposing CNS pharmacodynamic effects, with possible enzyme induction by phenobarbital.
What to do
Monitor alertness, seizure control and clinical response to both drugs. Adjust doses according to effect.
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 Dextroamphetamine
- Dextroamphetamine + Isocarboxazid Contraindicated
- Dextroamphetamine + Linezolid Contraindicated
- Dextroamphetamine + Methylene blue Contraindicated
- Dextroamphetamine + Phenelzine Contraindicated
- Dextroamphetamine + Rasagiline Contraindicated
- Dextroamphetamine + Safinamide Contraindicated
Frequently asked questions
Can I take Dextroamphetamine with Phenobarbital?
MediHelp rates the interaction as moderate. Dextroamphetamine and Phenobarbital 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. Phenobarbital sedates while dextroamphetamine stimulates, so the net effect is unpredictable and sedation may be masked. Phenobarbital also induces hepatic enzymes, which may lower the exposure of some co-administered drugs.
How serious is the interaction between Dextroamphetamine and Phenobarbital?
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 alertness, seizure control and clinical response to both drugs. Adjust doses according to effect.
What other medicines interact with Dextroamphetamine?
MediHelp also lists interactions of Dextroamphetamine with, for example, Isocarboxazid, Linezolid, Methylene blue. The full list is on the Dextroamphetamine page.
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