Drug interactions
Lofexidine + Pimozide
Severity: Major
Lofexidine and Pimozide: major interaction.
Last updated Sources: US FDA label
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 drugs can prolong the QT interval, and pimozide is a high-risk agent for torsades de pointes. Lofexidine also causes bradycardia, hypotension and sedation, which may add to pimozide's effects and increase arrhythmia risk.
What this interaction means in plain words
Lofexidine and Pimozide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Lofexidine belongs to Central Nervous System; Pimozide belongs to Central Nervous System.
Why it happens
Additive QT prolongation (pimozide via hERG blockade, lofexidine via its own QT effect and bradycardia) plus additive CNS depression.
What to do
Avoid the combination if possible; if used, obtain a baseline and follow-up ECG and correct potassium and magnesium. Monitor heart rate, blood pressure and sedation.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lofexidine and Pimozide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Other interactions of Lofexidine
- Adagrasib + Lofexidine Major
- Alfuzosin + Lofexidine Major
- Amiodarone + Lofexidine Major
- Amisulpride + Lofexidine Major
- Anagrelide + Lofexidine Major
- Apomorphine + Lofexidine Major
Frequently asked questions
Can I take Lofexidine with Pimozide?
MediHelp rates the interaction as major. Lofexidine and Pimozide can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs can prolong the QT interval, and pimozide is a high-risk agent for torsades de pointes. Lofexidine also causes bradycardia, hypotension and sedation, which may add to pimozide's effects and increase arrhythmia risk.
How serious is the interaction between Lofexidine and Pimozide?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination if possible; if used, obtain a baseline and follow-up ECG and correct potassium and magnesium. Monitor heart rate, blood pressure and sedation.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
