Drug interactions
Doxycycline + Fentanyl transdermal
Severity: Minor
Doxycycline and Fentanyl transdermal: minor 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
Fentanyl is a CYP3A4 substrate, but doxycycline is at most a weak inhibitor and no clinically significant interaction is established. The theoretical concern is increased opioid effect with respiratory depression.
What this interaction means in plain words
Doxycycline and Fentanyl transdermal have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible weak CYP3A4 inhibition reducing fentanyl clearance, not established for doxycycline.
What to do
No adjustment is routinely needed; monitor for excess sedation or slowed breathing, particularly at initiation of the antibiotic.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Doxycycline
- Acitretin + Doxycycline Contraindicated
- Aminolevulinic acid + Doxycycline Major
- Cholera vaccine + Doxycycline Major
- Doxycycline + Isotretinoin Major
- Doxycycline + Methoxyflurane Major
- Doxycycline + Microbiota Major
Frequently asked questions
Can I take Doxycycline with Fentanyl transdermal?
MediHelp rates the interaction as minor. Doxycycline and Fentanyl transdermal have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Fentanyl is a CYP3A4 substrate, but doxycycline is at most a weak inhibitor and no clinically significant interaction is established. The theoretical concern is increased opioid effect with respiratory depression.
How serious is the interaction between Doxycycline and Fentanyl transdermal?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No adjustment is routinely needed; monitor for excess sedation or slowed breathing, particularly at initiation of the antibiotic.
What other medicines interact with Doxycycline?
MediHelp also lists interactions of Doxycycline with, for example, Acitretin, Aminolevulinic acid, Cholera vaccine. The full list is on the Doxycycline page.
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