Drug interactions
Cyproheptadine + Difenoxin
Severity: Moderate
Cyproheptadine and Difenoxin: 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
Difenoxin is an opioid antidiarrheal metabolite of diphenoxylate with CNS depressant effects at higher exposures. With cyproheptadine, drowsiness and impaired alertness may increase, and additive anticholinergic effects may worsen constipation or ileus risk.
What this interaction means in plain words
Cyproheptadine and Difenoxin 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.
Cyproheptadine belongs to Respiratory; Difenoxin belongs to Gastrointestinal Tract.
Why it happens
Additive CNS depression from opioid receptor agonism and H1 antagonism, plus additive anticholinergic effects on gut motility.
What to do
Use the lowest effective doses and warn the patient about drowsiness. Monitor for abdominal distension or urinary retention and stop the antidiarrheal if these occur.
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 Cyproheptadine
- Cyproheptadine + Isocarboxazid Contraindicated
- Cyproheptadine + Phenelzine Contraindicated
- Cyproheptadine + Tranylcypromine Contraindicated
- Alfentanil + Cyproheptadine Major
- Belladonna and opium + Cyproheptadine Major
- Benzhydrocodone / acetaminophen + Cyproheptadine Major
Other interactions of Difenoxin
Frequently asked questions
Can I take Cyproheptadine with Difenoxin?
MediHelp rates the interaction as moderate. Cyproheptadine and Difenoxin 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. Difenoxin is an opioid antidiarrheal metabolite of diphenoxylate with CNS depressant effects at higher exposures. With cyproheptadine, drowsiness and impaired alertness may increase, and additive anticholinergic effects may worsen constipation or ileus risk.
How serious is the interaction between Cyproheptadine and Difenoxin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and warn the patient about drowsiness. Monitor for abdominal distension or urinary retention and stop the antidiarrheal if these occur.
What other medicines interact with Cyproheptadine?
MediHelp also lists interactions of Cyproheptadine with, for example, Isocarboxazid, Phenelzine, Tranylcypromine. The full list is on the Cyproheptadine page.
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