Drug interactions
Phendimetrazine + Risperidone
Severity: Minor
Phendimetrazine and Risperidone: 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
Phendimetrazine is a sympathomimetic anorectic whose stimulant effects may oppose risperidone's sedation. Stimulants can also worsen psychosis or agitation, which may reduce antipsychotic effectiveness. The clinical significance is uncertain.
What this interaction means in plain words
Phendimetrazine and Risperidone 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
Opposing pharmacodynamic effects: sympathomimetic CNS stimulation versus dopamine and serotonin receptor antagonism.
What to do
Monitor psychiatric symptoms and heart rate and blood pressure. Avoid anorectic stimulants in patients with active psychosis.
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 Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Frequently asked questions
Can I take Phendimetrazine with Risperidone?
MediHelp rates the interaction as minor. Phendimetrazine and Risperidone have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Phendimetrazine is a sympathomimetic anorectic whose stimulant effects may oppose risperidone's sedation. Stimulants can also worsen psychosis or agitation, which may reduce antipsychotic effectiveness. The clinical significance is uncertain.
How serious is the interaction between Phendimetrazine and Risperidone?
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 psychiatric symptoms and heart rate and blood pressure. Avoid anorectic stimulants in patients with active psychosis.
What other medicines interact with Risperidone?
MediHelp also lists interactions of Risperidone with, for example, Ibutilide, Vandetanib, Adagrasib. The full list is on the Risperidone page.
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