Drug interactions
Cyproheptadine + Phentermine
Severity: Minor
Cyproheptadine and Phentermine: 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
Cyproheptadine causes drowsiness whereas phentermine is a stimulant, so the effects may partly offset one another. No clinically important interaction is firmly established.
What this interaction means in plain words
Cyproheptadine and Phentermine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Cyproheptadine belongs to Respiratory; Phentermine belongs to Central Nervous System.
Why it happens
Opposing CNS effects; no established pharmacokinetic mechanism.
What to do
No routine intervention is needed; monitor response and appetite or alertness effects. Avoid assuming that stimulation protects against impairment.
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 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 Phentermine
- Isocarboxazid + Phentermine Contraindicated
- Linezolid + Phentermine Contraindicated
- Phenelzine + Phentermine Contraindicated
- Phentermine + Procarbazine Contraindicated
- Phentermine + Rasagiline Contraindicated
- Phentermine + Selegiline Contraindicated
Frequently asked questions
Can I take Cyproheptadine with Phentermine?
MediHelp rates the interaction as minor. Cyproheptadine and Phentermine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cyproheptadine causes drowsiness whereas phentermine is a stimulant, so the effects may partly offset one another. No clinically important interaction is firmly established.
How serious is the interaction between Cyproheptadine and Phentermine?
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 routine intervention is needed; monitor response and appetite or alertness effects. Avoid assuming that stimulation protects against impairment.
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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