Mesoridazine toxicity

The presence of metabolites with varying pharmacological profiles (e.g., some may be more effective than their parent compound [e.g., mesoridazine] some may not reach the brain [e.g., sulfoxides], and some may have greater toxicity than the parent compound)... 

CINACALCET BUPROPION T plasma concentrations of these substrates, with risk of toxic effects Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 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 alkylpiperidine group (Nos. 4-6) tends to be less effective and exhibits little antiemetic influence. However, they appear to have less extrapyramidal effect and may be considered to have the least toxicity of the four groups. Thioridazine has been reported to have the possibly unique property of inhibiting premature or nocturnal ejaculation in males without impairment of potency or orgasm. The active metabolite mesoridazine has not been similarly evaluated. 

In a large study in patients taking phenytoin with various phenothiazines (chlorpromazine, tMoridazine or mesoridazine), phenytoin levels were decreased by 44% when the phenothiazines were started, and by 33% when the phenothiazine dose was increased. A number of patients experienced an increased frequency of seizures. In patients who had these phenothiazines discontinued or the dosage decreased, the phenytoin levels increased by 55% and 71%, respectively, and toxic levels occurred in some patients. ... 

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