Acetaminophen And Codeine and Ganaxolone: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Ganaxolone
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Both of these medicines can slow down your brain and body. Codeine (the pain part of your acetaminophen and codeine pill) is an opioid that often causes drowsiness. Ganaxolone (Ztalmy), a seizure medicine, can also make you sleepy. Taken together, that sleepy, foggy feeling can add up, so you may feel more tired or slowed down than usual.
This is a known caution rather than something proven to cause harm, and your care team can manage it. Until you know how the combination affects you, be extra careful about driving or using machinery. Let your pharmacist or doctor know if you feel very drowsy.
Effect: Additive CNS depression, increasing risk of somnolence and sedation.
Mechanism: Pharmacodynamic (PD) additive effect. Codeine (opioid agonist) and ganaxolone (neuroactive steroid, positive allosteric GABA-A modulator) both depress the CNS. This is a PD interaction, not a metabolic one.
- Direction: Increased sedative effect of the combination.
- Onset: Unspecified.
- Evidence: Theoretical.
- Management: Monitor for somnolence and sedation. Counsel against driving or operating machinery until tolerance is established. Dose may be individualized by the care team; consider closer monitoring or dose review if excessive sedation occurs.
What happens
An increased risk of somnolence and sedation
Interaction Deep Dive
Concomitant use of ganaxolone with CNS depressants may increase the risk of somnolence and sedation. Monitor patients for somnolence and sedation, and advise patients not to drive or operate machinery until they have gained sufficient experience on ganaxolone to gauge whether it adversely affects their ability to drive or operate machinery1.
Why it happens (mechanism)
Additive CNS depression
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. Here is how this is typically handled:
- Your team may monitor you more closely for drowsiness and sedation, especially when you start or change either medicine.
- Doses may be adjusted and individualized by your prescriber if you feel too sleepy.
- Do not drive or operate machinery until you know how the combination affects you.
Tell your pharmacist or doctor if you feel unusually drowsy, confused, or hard to wake, or if the sleepiness makes daily activities difficult.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Ganaxolone together?
Taking codeine (in acetaminophen and codeine) with ganaxolone can add up to make you sleepier, so avoid driving until you know how you feel and let your care team know if drowsiness is a problem. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Ganaxolone interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Acetaminophen And Codeine and Ganaxolone interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. Here is how this is typically handled: Your team may monitor you more closely for drowsiness and sedation, especially when you start or change either medicine. Doses may be adjusted and individualized by your prescriber if you feel too sleepy. Do not drive or operate machinery until you know how the combination aff… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine or Ganaxolone need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: ZTALMY® oral suspension, ganaxolone oral suspension. Marinus Pharmaceuticals Inc (per FDA), Radnor, PA, 2025. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Ganaxolone
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