Drug interactions
Methamphetamine + Phenobarbital
Severity: Moderate
Methamphetamine 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
Methamphetamine is a stimulant and phenobarbital is a sedative anticonvulsant, so their effects on arousal oppose each other. Stimulation may hide sedation, and methamphetamine can lower the seizure threshold, which is relevant in patients taking phenobarbital for epilepsy.
What this interaction means in plain words
Methamphetamine 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 pharmacodynamic effects on the central nervous system; phenobarbital is also a CYP inducer, but the effect on methamphetamine exposure is not well characterized.
What to do
Monitor seizure control, alertness and cardiovascular parameters. Do not use methamphetamine to offset barbiturate sedation.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Methamphetamine and Phenobarbital, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Methamphetamine
- Isocarboxazid + Methamphetamine Contraindicated
- Linezolid + Methamphetamine Contraindicated
- Methamphetamine + Phenelzine Contraindicated
- Methamphetamine + Procarbazine Contraindicated
- Methamphetamine + Rasagiline Contraindicated
- Methamphetamine + Safinamide Contraindicated
Frequently asked questions
Can I take Methamphetamine with Phenobarbital?
MediHelp rates the interaction as moderate. Methamphetamine 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. Methamphetamine is a stimulant and phenobarbital is a sedative anticonvulsant, so their effects on arousal oppose each other. Stimulation may hide sedation, and methamphetamine can lower the seizure threshold, which is relevant in patients taking phenobarbital for epilepsy.
How serious is the interaction between Methamphetamine 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 seizure control, alertness and cardiovascular parameters. Do not use methamphetamine to offset barbiturate sedation.
What other medicines interact with Methamphetamine?
MediHelp also lists interactions of Methamphetamine with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Methamphetamine page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
