Drug interactions
Codeine + Fenfluramine
Severity: Moderate
Codeine and Fenfluramine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Fenfluramine can cause somnolence and has serotonergic activity, while codeine is an opioid with CNS depressant effects. Combined use may increase drowsiness, and serotonin toxicity is a theoretical concern.
What this interaction means in plain words
Codeine and Fenfluramine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Codeine belongs to Musculoskeletal; Fenfluramine belongs to Central Nervous System.
Why it happens
Additive CNS depression; fenfluramine serotonin release may add to opioid serotonergic activity.
What to do
Monitor for sedation, agitation, tremor or other signs of serotonin toxicity, and adjust the codeine dose accordingly.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Codeine
- Alvimopan + Codeine Contraindicated
- Codeine + Isocarboxazid Contraindicated
- Codeine + Olanzapine / samidorphan Contraindicated
- Codeine + Phenelzine Contraindicated
- Codeine + Tranylcypromine Contraindicated
- Alfentanil + Codeine Major
Other interactions of Fenfluramine
- Fenfluramine + Isocarboxazid Contraindicated
- Fenfluramine + Linezolid Contraindicated
- Fenfluramine + Phenelzine Contraindicated
- Fenfluramine + Selegiline Contraindicated
- Fenfluramine + Tranylcypromine Contraindicated
- Almotriptan + Fenfluramine Major
Frequently asked questions
Can I take Codeine with Fenfluramine?
MediHelp rates the interaction as moderate. Codeine and Fenfluramine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Fenfluramine can cause somnolence and has serotonergic activity, while codeine is an opioid with CNS depressant effects. Combined use may increase drowsiness, and serotonin toxicity is a theoretical concern.
How serious is the interaction between Codeine and Fenfluramine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for sedation, agitation, tremor or other signs of serotonin toxicity, and adjust the codeine dose accordingly.
What other medicines interact with Codeine?
MediHelp also lists interactions of Codeine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Codeine page.
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