Drug interactions
Fentanyl + Methyclothiazide
Severity: Minor
Fentanyl and Methyclothiazide: 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
Opioids can promote antidiuretic hormone release and may cause urinary retention, which could blunt the diuretic effect of a thiazide. The effect is variable and usually of limited clinical importance.
What this interaction means in plain words
Fentanyl and Methyclothiazide 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
Opioid-induced ADH release and urinary retention may oppose thiazide-induced diuresis; the evidence is largely theoretical.
What to do
Monitor fluid balance, weight and blood pressure after starting fentanyl. Adjust the diuretic only if fluid retention develops.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
Frequently asked questions
Can I take Fentanyl with Methyclothiazide?
MediHelp rates the interaction as minor. Fentanyl and Methyclothiazide have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Opioids can promote antidiuretic hormone release and may cause urinary retention, which could blunt the diuretic effect of a thiazide. The effect is variable and usually of limited clinical importance.
How serious is the interaction between Fentanyl and Methyclothiazide?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor fluid balance, weight and blood pressure after starting fentanyl. Adjust the diuretic only if fluid retention develops.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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