Perphenazine has been used in low doses as a 'normal' or 'minor' tranquilizer in patients with a known history of addiction to drugs or alcohol, a practice which is now strongly discouraged.
Perphenazine has sedating and anxiolytic properties, making the drug useful for the treatment of agitated psychotic patients and, in high doses (up to 100 mg per day), for patients with life-threatening (febrile) catatonia, a state in which the patients are extremely agitated, but unable to express themselves.