Mesoridazine drug interactions

Hypersensitivity to the drug or any other component of the product (cross-sensitivity between phenothiazines may occur) comatose or greatly depressed states caused by CNS depressants or from any other cause (phenothiazines, clozapine, loxapine, molindone, pimozide, haloperidol) coadministration with other drugs that prolong the QT interval and in patients with congenital long QT syndrome or history of cardiac arrhythmias (mesoridazine, thioridazine, pimozide, ziprasidone see Drug..Interactions). 

Initiate therapy of these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. hydrocodone, oxycodone, desipramine, paroxetine, chlorpheniramine, mesoridazine, alprenolol, amphetamines, atomoxetine)... 

The general importance of this alleged interaction is uncertain but the authors of the report suggest that ephedrine-like drugs such as phenylpropanolamine should not be given to patients taking thioridazine or mesoridazine. 

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