Acetaminophen And Codeine and Scopolamine: 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
Scopolamine
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.
Your pain medicine contains codeine, which can make you sleepy, dizzy, or foggy, and can slow down your gut and bladder. Scopolamine can do many of the same things. Taken together, these effects can add up, so you might feel more drowsy or lightheaded than usual.
There is also a real concern about your bowels and bladder. Both drugs can slow things down, which could lead to severe constipation or trouble urinating. This is based more on how these drugs work than on lots of case reports, but it is worth taking seriously. Please talk with your pharmacist or doctor. Your care team can manage this safely.
Effect: Additive CNS depression and additive anticholinergic/antimotility effects when codeine (in acetaminophen-codeine) is combined with scopolamine.
- Mechanism: Pharmacodynamic, additive. Both agents cause sedation; codeine (opioid) plus scopolamine (antimuscarinic) additively reduce GI motility and can promote urinary retention, risking paralytic ileus.
- Direction: Potentiated scopolamine/sedative effects (increases effect).
- Evidence: Theoretical; severity major; onset unspecified.
- Management: Prefer one agent based on clinical need. If combined, monitor for excess sedation, dizziness, disorientation, and for urinary retention or reduced gastric motility.
What happens
Increased or potentiated scopolamine effects, an increased risk of CNS depression and an increased risk of paralytic ileus
Interaction Deep Dive
When scopolamine is taken together with other agents that produce CNS adverse reactions such as drowsiness, dizziness, or disorientation, for example codeine, the effects of scopolamine may be potentiated. Select either scopolamine or the CNS depressant based on how important each drug is for the patient. Should the combination be unavoidable, watch patients for CNS adverse reactions2. In addition, giving codeine alongside an anticholinergic such as scopolamine can lead to urinary retention or severe constipation that results in paralytic ileus. Observe patients for indications of urinary retention or decreased gastric motility whenever codeine is administered concurrently with anticholinergic drugs1.
Why it happens (mechanism)
Additive CNS depression; additive effects on gastric motility
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. Because these effects add together, your team may choose to use only one of them, or adjust and individualize your doses and monitor you more closely.
- Watch for extra drowsiness, dizziness, or confusion, especially when starting.
- Report trouble urinating, severe constipation, or belly pain and bloating promptly.
- Avoid alcohol or other sedatives unless cleared by your team.
- Ask your pharmacist or prescriber whether both are truly needed at the same time.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Scopolamine together?
Combining codeine (in your acetaminophen-codeine) with scopolamine can add up to more drowsiness and can seriously slow your gut and bladder, so tell your care team and watch for constipation or trouble urinating. They can manage this by picking one drug or monitoring you closely. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Scopolamine 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 Scopolamine interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. Because these effects add together, your team may choose to use only one of them, or adjust and individualize your doses and monitor you more closely. Watch for extra drowsiness, dizziness, or confusion, especially when starting. Report trouble urinating, severe constipation, or belly pain and bloating promptly. Av… 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 Scopolamine 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: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
- Product Information: TRANSDERM SCOP transdermal system patch, scopolamine transdermal system patch. Baxter Healthcare Corporation (per FDA), Deerfield, IL, 2025. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Scopolamine
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