Drug interactions
Diamorphine + Perphenazine
Severity: Moderate
Diamorphine and Perphenazine: 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
Combining a phenothiazine antipsychotic with an opioid produces additive central nervous system depression. Patients may experience excessive sedation, hypotension and respiratory depression, especially at higher doses or in frail patients.
What this interaction means in plain words
Diamorphine and Perphenazine 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 CNS and respiratory depression from opioid receptor agonism plus antipsychotic sedative and alpha-adrenergic blocking effects.
What to do
Start with lower doses of the opioid and titrate carefully while monitoring sedation, blood pressure and respiratory rate. Avoid additional CNS depressants where possible.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Diamorphine with Perphenazine?
MediHelp rates the interaction as moderate. Diamorphine and Perphenazine 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. Combining a phenothiazine antipsychotic with an opioid produces additive central nervous system depression. Patients may experience excessive sedation, hypotension and respiratory depression, especially at higher doses or in frail patients.
How serious is the interaction between Diamorphine and Perphenazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with lower doses of the opioid and titrate carefully while monitoring sedation, blood pressure and respiratory rate. Avoid additional CNS depressants where possible.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine page.
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