Trifluoperazine adverse effects

A study, undertaken to confirm the involvement of the cytochrome P450 isoenzyme CYT2D6 in the metabolism of trazodone, found that when 11 depressed patients were given trazodone 150 to 300 mg at bedtime for 18 weeks, and then with thioridazine 20 mg twice daily for one week, the plasma levels of the trazodone and its active metabolite, /w-chlorophenyl-piperazine, rose by 36% and 54%, respectively. No adverse reactions were described. In contrast, a case of fatal hepatic necrosis with cholestasis has been attributed to the concurrent use of trazodone and phenothiazines. A 72-year-old woman taking trifluoperazine, trazodone and lithium carbonate developed an elevated alanine aminotransferase level. Trifluoperazine was replaced with thioridazine, but 9 weeks later she became jaundiced and developed hepatic encephalopathy, and died 6 weeks after the onset of jaundice. The authors consider that the combination of the phenothiazines and trazodone were the cause of her hepatic necrosis both phenothiazines and trazodone have been reported to individually cause hepatic adverse effects. ... 

The hypotensive adverse effects of chlorpromazine and other phenothiazines may be additive with the antihypertensive effects of methyldopa. Patients may feel faint and dizzy if they stand up quickly. An isolated report describes paradoxical hypertension in a patient given methyldopa and trifluoperazine. 

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