Drug interactions
Isoflurane + Trifluoperazine
Severity: Moderate
Isoflurane and Trifluoperazine: 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
Both isoflurane and the phenothiazine trifluoperazine can affect cardiac repolarization, and phenothiazines are associated with QT prolongation and torsades de pointes. Trifluoperazine also adds sedation and alpha-blockade, which can worsen hypotension under anesthesia. The risk is greater with electrolyte abnormalities or other QT-prolonging drugs.
What this interaction means in plain words
Isoflurane and Trifluoperazine 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 effects on cardiac repolarization, plus additive CNS depression and alpha-adrenergic blockade.
What to do
Check ECG and electrolytes before surgery and monitor ECG and blood pressure during anesthesia. Treat hypotension with a direct-acting vasopressor such as phenylephrine rather than relying on mixed agents.
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 Isoflurane
Frequently asked questions
Can I take Isoflurane with Trifluoperazine?
MediHelp rates the interaction as moderate. Isoflurane and Trifluoperazine 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. Both isoflurane and the phenothiazine trifluoperazine can affect cardiac repolarization, and phenothiazines are associated with QT prolongation and torsades de pointes. Trifluoperazine also adds sedation and alpha-blockade, which can worsen hypotension under anesthesia. The risk is greater with electrolyte abnormalities or other QT-prolonging drugs.
How serious is the interaction between Isoflurane and Trifluoperazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check ECG and electrolytes before surgery and monitor ECG and blood pressure during anesthesia. Treat hypotension with a direct-acting vasopressor such as phenylephrine rather than relying on mixed agents.
What other medicines interact with Isoflurane?
MediHelp also lists interactions of Isoflurane with, for example, Adrenaline-articaine, Amisulpride, Arsenic trioxide. The full list is on the Isoflurane page.
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