Acetaminophen And Codeine and Lomitapide: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Lomitapide
No brand names on record
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.
These two medicines can interact. Codeine is a pain medicine that your body has to turn into morphine to work. Lomitapide can slow down one of the liver enzymes (called CYP3A4) that handles codeine. When that enzyme is slowed, more codeine and morphine can build up in your body.
This means you could feel stronger opioid effects, like heavy drowsiness or slowed breathing. That can be serious, though this concern is based on how the drugs work rather than lots of real-world cases. Please don't stop either medicine on your own. Your care team can manage this safely by adjusting your dose if needed and watching you a bit more closely.
Effect: Increased codeine and active morphine exposure via lomitapide inhibition of CYP3A4-mediated codeine metabolism. Codeine is a prodrug; CYP2D6 forms morphine, but reduced CYP3A4 clearance shunts more codeine toward the active pathway and raises parent and morphine concentrations.
- Direction: Increased opioid effect (increased_drug_effect).
- Risk: Enhanced/prolonged adverse effects, including potentially fatal respiratory depression.
- Onset: Unspecified; risk highest when inhibitor added to stable codeine dose.
- Evidence: Theoretical.
Management: Monitor for sedation and respiratory depression; consider codeine dose reduction until stable effects observed. On lomitapide discontinuation, monitor for withdrawal and consider increasing codeine.
What happens
Increased codeine and morphine exposure
Interaction Deep Dive
Taking codeine together with CYP3A4 inhibitors has led to elevated levels of both codeine and morphine, an effect that may intensify or extend adverse reactions and could produce respiratory depression with the potential to be fatal, especially if the inhibitor is introduced once a patient has been stabilized on codeine. When the two agents must be used together, watch patients carefully for sedation and respiratory depression, and consider lowering the codeine dose until steady drug effects are seen. Should the CYP3A4 inhibitor be withdrawn, observe patients for indications of opioid withdrawal, and consider raising the codeine dose until stable drug effects have been observed12.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated codeine metabolism
How to manage this interaction
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. Here is what a care team typically does with this combination:
- Watch more closely for excess sedation and slowed or shallow breathing, especially soon after starting lomitapide.
- Your codeine dose may need to be adjusted and individualized by your care team until your response is steady.
- If lomitapide is later stopped, they may watch for opioid withdrawal and reconsider your codeine dose.
Call your pharmacist or doctor if you notice unusual drowsiness, confusion, or trouble breathing. Seek emergency help for very slow or difficult breathing.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Lomitapide together?
Lomitapide can slow codeine's breakdown and raise morphine levels, which may cause dangerous drowsiness or slowed breathing. Keep taking both as prescribed and let your care team adjust the dose and monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Lomitapide interaction?
It is rated major. Potentially serious — often needs a change or close 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 Lomitapide interaction managed?
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. Here is what a care team typically does with this combination: Watch more closely for excess sedation and slowed or shallow breathing, especially soon after starting lomitapide. Your codeine dose may need to be adjusted and individualized by your care team until your response is steady. If lomitapide is later stop… 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 Lomitapide 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 a safer alternative to one of these medications for me?
References (2)
- Product Information: Codeine sulfate oral solution, codeine sulfate oral solution. Hikma Pharmaceuticals USA Inc(per FDA), Berkeley Heights, NJ, 2023. DailyMed
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. Hikma Pharmaceuticals USA Inc. (per FDA), Berkeley Heights, NJ, 2023. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Lomitapide
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