Acetaminophen And Codeine and Pimozide: 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
Pimozide
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.
Taking these two together can add up in ways to watch. Codeine is an opioid pain and cough medicine that can make you sleepy, slow your breathing, and slow your gut. Pimozide is used for certain conditions and can also cause drowsiness and slow the movement of your bowels. Used together, these effects can stack up, leading to heavy sedation, slower breathing, and problems like severe constipation or trouble urinating.
The good news is your care team can manage this. Please do not stop either medicine on your own. Talk with your pharmacist or doctor, who may adjust doses and keep a closer eye on how you feel.
Additive CNS and GI effects between codeine (an opioid) and pimozide.
- Direction/effect: Additive CNS and respiratory depression; additive reduction in gastric motility with risk of severe constipation, urinary retention, and paralytic ileus.
- Mechanism: Additive pharmacodynamic effects on sedation, respiratory drive, and gut motility. (Note: codeine is a prodrug activated via CYP2D6, but this interaction is pharmacodynamic, not metabolic.)
- Evidence/onset: Theoretical; onset unspecified.
- Management: Avoid where alternatives suffice. If combined, use lowest dose/shortest duration; monitor sedation, respiratory status, urinary retention, and bowel motility; consider naloxone availability.
What happens
Increased risk of paralytic ileus and an increased risk of respiratory and CNS depression
Interaction Deep Dive
Do not combine opioid cough medication formulations with CNS depressants2. The joint use of codeine and CNS depressants should be limited to patients in whom other options prove insufficient. When such combined use cannot be avoided, employ the smallest dose and the briefest duration required to meet treatment objectives. Furthermore, giving codeine together with anticholinergics can raise the likelihood of urinary retention and/or severe constipation, potentially progressing to paralytic ileus. A reduced dose of either codeine or the CNS depressant should be considered, along with close observation for urinary retention, diminished gastric motility, sedation, and respiratory depression. Should concurrent use be justified, prescribing naloxone for the emergency management of opioid overdose is worth considering 134.
Why it happens (mechanism)
Additive effects on gastric motility; additive CNS depression
How to manage this interaction
This combination can be managed with care. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise.
- Your team may choose an alternative when one is adequate, or use the lowest dose and shortest duration needed.
- They may lower the dose of one medicine and monitor you more closely for drowsiness, slowed breathing, constipation, or trouble urinating.
- In some cases they may prescribe naloxone as an emergency backup.
Tell your pharmacist or doctor right away if you feel very sleepy, breathe slowly, or cannot have a bowel movement or urinate.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
4 reports — tap to read
a) In a study, emergency department visits related to nonmedical use that took place between 2004 and 2011 and involved opioid analgesics and benzodiazepines rose significantly from 11 to 34.2 per 100,000. Deaths from drug overdose attributable to prescribed and higher than prescribed doses of both drug classes likewise rose significantly from 0.6 to 1.7 per 100,000, and overdose deaths attributable to benzodiazepines rose significantly from 18% to 31% 2.
b) In a prospective cohort study, the rate of overdose deaths involving the dispensing of both opioid analgesics and benzodiazepines was 10 times greater than that seen with the dispensing of opioid analgesics alone (7 vs 0.7 per 10,000 person years) 2.
c) In a cohort study using data from 2004 to 2009, the risk of fatal overdose rose significantly by 2.33 fold among patients taking opioid analgesics who had a history of a benzodiazepine prescription and rose by 3.86 fold among those with a current benzodiazepine prescription, compared with patients taking opioid analgesics who had no history of a benzodiazepine prescription. The risk of drug overdose deaths grew as daily benzodiazepine doses increased 2.
d) Observational studies have shown that using opioid analgesics and benzodiazepines together raises the risk of drug-related mortality compared with using opioid analgesics alone. Owing to comparable pharmacological properties, it is reasonable to anticipate a similar risk when other CNS depressant drugs are used concomitantly with opioid analgesics 34.
Common questions
Can I take Acetaminophen And Codeine and Pimozide together?
Combining codeine with pimozide can add up to more sedation, slowed breathing, and severe constipation or urinary retention, so it should be avoided when possible. Keep taking both as prescribed and let your care team adjust doses and monitor you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Pimozide 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 Pimozide interaction managed?
This combination can be managed with care. Keep taking both medicines exactly as prescribed unless your care team tells you otherwise. Your team may choose an alternative when one is adequate, or use the lowest dose and shortest duration needed. They may lower the dose of one medicine and monitor you more closely for drowsiness, slowed breathing, constipation, or trouble urinating. In some cases t… 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 Pimozide 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 (4)
- Product Information: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
- US Food and Drug Administration (FDA): Drug Safety Communications: FDA warns about serious risks and death when combining opioid pain or cough medicines with benzodiazepines; requires its strongest warning. US Food and Drug Administration (FDA). Silver Spring, MD. 2016.
- 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 Pimozide
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