Pecazine (
INN), also known as mepazine (trade name Pacatal), is a
phenothiazine formerly used as a
neuroleptic drug or
major tranquilizer.
Pecazine was first synthesized in 1953 by
Wilhelm Schuler and Otto Nieschulz and was quickly incorporated into psychiatric practice as an
ataractic, i.e., a true tranquilizer rather than a hypnotic or depressant. It was considered interchangeable with
chlorpromazine
Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar d ...
, albeit with a different side effect profile, which included less sedation and a lower risk of
extrapyramidal symptoms due to its potent
parasympatholytic and
anticholinergic
Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system.
These agents inhibit the parasympatheti ...
effect.
As early as 1958, however, studies reported inferiority to other phenothiazines in the treatment of
schizophrenia
Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
and questioned its place in the clinic;
in 1960, a double-blind, randomized controlled trial found pecazine to be no more effective than placebo.
Subsequent research found that, like the structurally related
promethazine, pecazine is essentially devoid of
antipsychotic
Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), p ...
activity.
Pecazine was implicated in a number of cases of
agranulocytosis and was subsequently withdrawn from the market.
More recently, it has become a subject of research interest as a
MALT1 and
RANKL inhibitor.
References
Phenothiazines
Withdrawn drugs
{{nervous-system-drug-stub