Tramadol and Chloroquine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tramadol
Chloroquine
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.
What happens
Increased traMADol exposure, reduced exposure of the active metabolite and an increased risk of seizure
Interaction Deep Dive
Concomitant use of traMADol with seizure threshold lowering CYP2D6 inhibitors increase exposure of traMADol, and reduce exposure of M1, the active metabolite of traMADol and reduce in M1 exposure, particularly when an inhibitor is added after a stable dose of traMADol is achieved and may also increase risk of seizure. Risk of seizure may also increase in patients with epilepsy, those with a history of seizures, or in patients with a recognized risk for seizure (such as head trauma, metabolic disorders, alcohol and drug withdrawal, CNS infections). Reduced M1 exposure could result in reduced therapeutic effects, and may result in signs and symptoms of opioid withdrawal and reduced efficacy while an increase in traMADol exposure can increase the risk of seizures and serotonin syndrome. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the traMADol exposure will decrease and the M1 plasma concentration will increase. This could increase or prolong therapeutic effects but also increase adverse reactions related to opioid toxicity, such as potentially fatal respiratory depression. If use of a CYP2D6 inhibitor is necessary in a patient receiving traMADol, closely monitor for seizures, serotonin syndrome, or opioid withdrawal. When discontinuing a CYP2D6 inhibitor in a patient receiving traMADol, consider a traMADol dose reduction and monitor for signs of respiratory depression or sedation1.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated metabolism of traMADol; additive lowering of seizure threshold
Common questions
Can I take Tramadol and Chloroquine together?
Increased traMADol exposure, reduced exposure of the active metabolite and an increased risk of seizure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tramadol and Chloroquine 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 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 Tramadol or Chloroquine 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 (1)
- Product Information: Tramadol hydrochloride oral tablets, tramadol hydrochloride oral tablets. Strides Pharma, Inc (per DailyMed), East Brunswick, NJ, 2025. DailyMed
Keep reading about Tramadol
Keep reading about Chloroquine
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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.
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