Moxifloxacin and Thioridazine interaction
Moxifloxacin and Thioridazine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Thioridazine (Thioridazine Hydrochloride) label · effective 2026-03-02
CONTRAINDICATIONS Thioridazine hydrochloride tablet use should be avoided in combination with other drugs that are known to prolong the QTc interval and in patients with congenital long QT syndrome or a history of cardiac arrhythmias.
Such an increased risk may result also from the additive effect of coadministering thioridazine with other agents that prolong the QTc interval.
From the Moxifloxacin label · effective 2024-05-06
Pharmacokinetic studies between moxifloxacin and other drugs that prolong the QT interval such as cisapride, erythromycin, antipsychotics, and tricyclic antidepressants have not been performed.
Drugs that Prolong QT There is limited information available on the potential for a pharmacodynamic interaction in humans between moxifloxacin and other drugs that prolong the QTc interval of the electrocardiogram.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.