Drug interactions
Fentanyl transdermal + Loperamide
Severity: Moderate
Fentanyl transdermal and Loperamide: 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
Loperamide is an opioid, and at high doses or with raised systemic exposure it can add to the CNS and respiratory depression caused by fentanyl. At usual doses systemic effects are limited, but concurrent use in patients on potent opioids can contribute to sedation and respiratory depression. Both drugs also slow gut motility, increasing the risk of constipation and ileus.
What this interaction means in plain words
Fentanyl transdermal and Loperamide 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.
Why it happens
Additive opioid-receptor mediated CNS and respiratory depression and additive reduction of gastrointestinal motility.
What to do
Keep loperamide at labeled doses and avoid higher-than-recommended use in patients on fentanyl. Monitor for sedation, respiratory depression and constipation or ileus.
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 Loperamide
Frequently asked questions
Can I take Fentanyl transdermal with Loperamide?
MediHelp rates the interaction as moderate. Fentanyl transdermal and Loperamide 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. Loperamide is an opioid, and at high doses or with raised systemic exposure it can add to the CNS and respiratory depression caused by fentanyl. At usual doses systemic effects are limited, but concurrent use in patients on potent opioids can contribute to sedation and respiratory depression. Both drugs also slow gut motility, increasing the risk of constipation and ileus.
How serious is the interaction between Fentanyl transdermal and Loperamide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Keep loperamide at labeled doses and avoid higher-than-recommended use in patients on fentanyl. Monitor for sedation, respiratory depression and constipation or ileus.
What other medicines interact with Loperamide?
MediHelp also lists interactions of Loperamide with, for example, Amiodarone, Amisulpride, Anagrelide. The full list is on the Loperamide page.
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