Sertraline and Dihydrocodeine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Dihydrocodeine
No brand names on recordSertraline
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.
Here's what's going on. Dihydrocodeine is a pain medicine that your body has to switch on into its active, pain-relieving form using a liver enzyme called CYP2D6. Sertraline (an antidepressant) can slow that same enzyme down. So the pain relief may end up weaker than expected, and a few people could even feel mild opioid withdrawal (like restlessness or feeling flu-ish).
There's also a second concern: both medicines affect serotonin in the body. Rarely, combining them can lead to serotonin syndrome, with symptoms like agitation, fast heartbeat, sweating, shivering, or muscle twitching. The good news is your care team can manage this by watching how you respond and adjusting your dose. Keep taking both as prescribed and call your doctor or pharmacist with any of the symptoms above.
Mechanism (dual): Sertraline inhibits CYP2D6, reducing conversion of dihydrocodeine to its more active opioid metabolite. Because dihydrocodeine relies on this bioactivation (prodrug-like behavior), expect reduced analgesic efficacy and possible withdrawal, alongside increased parent-drug exposure. Additive serotonergic activity also raises serotonin syndrome risk.
- Direction: reduced active-metabolite effect; additive serotonergic PD risk
- Severity/evidence: major, theoretical; onset unspecified
- Monitor: analgesic response, withdrawal signs, and serotonin toxicity (clonus, hyperthermia, autonomic instability, agitation) especially at initiation/titration
- Manage: individualize dosing; consider increasing dihydrocodeine if efficacy inadequate; if sertraline is stopped, consider lowering dihydrocodeine and watch for respiratory depression; discontinue opioid if serotonin syndrome suspected
What happens
Increased dihydrocodeine exposure, reduced exposure of active metabolite, and increased risk of serotonin syndrome
Interaction Deep Dive
Serotonin syndrome has been reported when opioids like dihydrocodeine are taken together with serotonergic agents. Should combined use be required, the patient must be watched closely, especially at the start of therapy and whenever doses are changed. If serotonin syndrome is suspected, stop dihydrocodeine. Furthermore, using dihydrocodeine alongside a CYP2D6 inhibitor can lower plasma levels of morphine, the active metabolite of codeine, which may diminish opioid effectiveness and, in certain patients, produce signs or symptoms of opioid withdrawal. When such combined use cannot be avoided, watch for withdrawal manifestations and consider raising the dihydrocodeine dose. Upon stopping a concurrent CYP2D6 inhibitor, a reduction in the dihydrocodeine dose should be considered along with monitoring for respiratory depression12.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated dihydrocodeine metabolism; additive serotonergic effects
How to manage this interaction
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination is usually manageable with attention and monitoring.
- Your care team may watch your response closely, especially when either medicine is started or the dose is changed.
- Because pain relief may be weaker, the dihydrocodeine dose may need to be adjusted and individualized by your team.
- Tell them if you notice opioid withdrawal (restlessness, sweating, stomach cramps, chills).
- Seek prompt care for possible serotonin syndrome: agitation, rapid heartbeat, fever, shivering, muscle twitching, or confusion.
- If sertraline is ever stopped, mention it, since your opioid dose may need review.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Sertraline and Dihydrocodeine together?
Sertraline can blunt dihydrocodeine's pain relief and, rarely, add to serotonin syndrome risk; keep taking both as prescribed and report weaker pain control, withdrawal symptoms, or agitation/fever/twitching to your care team. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sertraline and Dihydrocodeine 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 Sertraline and Dihydrocodeine interaction managed?
Keep taking both medicines as prescribed unless your prescriber tells you otherwise. This combination is usually manageable with attention and monitoring. Your care team may watch your response closely, especially when either medicine is started or the dose is changed. Because pain relief may be weaker, the dihydrocodeine dose may need to be adjusted and individualized by your team. Tell them if y… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Sertraline or Dihydrocodeine 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: TREZIX(TM) oral capsules, acetaminophen caffeine dihydrocodeine bitartrate oral capsules. WraSer Pharmaceuticals (per DailyMed), Ridgeland, MS, 2016. DailyMed
- Product Information: SYNALGOS(R)-DC oral capsules, aspirin, caffeine, dihydrocodeine bitartrate oral capsules. Sun Pharmaceuticals Industries Inc (per FDA), Cranbury, NJ, 2023. DailyMed
Keep reading about Dihydrocodeine
Keep reading about Sertraline
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist