Major
Haloperidol × Moxifloxacin
First-generation antipsychotics. Butyrophenone derivatives×Fourth-generation fluoroquinolone
Mechanism
Haloperidol prolongs QT, moxifloxacin too. Additive torsades risk.
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
Alternative – levofloxacin for infection, or non-QT AP.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Sources
- FDA: Avelox (moxifloxacin) prescribing information – QT prolongation warning (2016)– FDA Avelox label, Warnings and Precautions §5.7 – avoid with QT-prolonging drugs
- BNF: BNF – Haloperidol interactions (2024)