Drug interactions
Perphenazine + Timolol
Severity: Moderate
Perphenazine and Timolol: 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
Perphenazine inhibits CYP2D6 and can increase timolol concentrations, leading to more bradycardia and hypotension. Perphenazine itself can also cause orthostatic hypotension.
What this interaction means in plain words
Perphenazine and Timolol 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.
Perphenazine belongs to Central Nervous System; Timolol belongs to Cardiovascular.
Why it happens
CYP2D6 inhibition reduces timolol metabolism, with additive hypotensive effects from phenothiazine alpha-blockade.
What to do
Monitor heart rate and blood pressure when starting or stopping perphenazine. Reduce the timolol dose if bradycardia or hypotension occurs.
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 Timolol
- Acebutolol + Timolol Major
- Albuterol + Timolol Major
- Aldesleukin + Timolol Major
- Amifostine + Timolol Major
- Amiodarone + Timolol Major
- Arformoterol + Timolol Major
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 Perphenazine with Timolol?
MediHelp rates the interaction as moderate. Perphenazine and Timolol 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. Perphenazine inhibits CYP2D6 and can increase timolol concentrations, leading to more bradycardia and hypotension. Perphenazine itself can also cause orthostatic hypotension.
How serious is the interaction between Perphenazine and Timolol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate and blood pressure when starting or stopping perphenazine. Reduce the timolol dose if bradycardia or hypotension occurs.
What other medicines interact with Timolol?
MediHelp also lists interactions of Timolol with, for example, Acebutolol, Albuterol, Aldesleukin. The full list is on the Timolol page.
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