Information about Phenothiazines
Chlorpromazine is a phenothiazine that was once the most commonly prescribed antipsychotic agent, but that is now rarely used.
Liver safety of Phenothiazines
Chlorpromazine can cause mild and transient serum enzyme elevations and is also a well known cause of clinically apparent acute and chronic cholestatic liver injury.
Mechanism of action of Phenothiazines
Chlorpromazine (klor proe' ma zeen) is a tricyclic aliphatic phenothiazine which acts by postsynaptic inhibition of dopamine receptors. Chlorpromazine has other peripheral and central nervous system effects, producing both alpha adrenergic stimulation and blocking histamine- and serotonin-mediated effects. Chlorpromazine is indicated for the therapy of acute and chronic psychosis and for nausea and intractable hiccups.
FDA approval information for Phenothiazines
Chlorpromazine was approved for use in the United States in 1957 and was formerly the most commonly prescribed antipsychotic medication, being the prototypic, standard neuroleptic agent against which other antipsychotic agents were tested. In recent years, chlorpromazine has been replaced in large part by the atypical antipsychotics, which have fewer extrapyramidal and hepatic side effects. Current indications include psychotic disorders, schizophrenia, nausea and vomiting, acute intermittent porphyria and intractable hiccups.
Dosage and administration for Phenothiazines
Chlorpromazine is available in multiple generic forms as tablets of 10, 25, 50, 100 and 200 mg, as extended release capsules of 200 and 300 mg, and as syrup in various concentrations. Parenteral forms are also available. Chlorpromazine was formerly available under the brand names Thorazine and Largactil. The typical maintenance dose of chlorpromazine is 100 to 200 mg daily. Common side effects include drowsiness, dizziness, headache, blurred vision, dry mouth, constipation, tremor, restlessness, muscle spasms and weight gain.
Second Generation (Atypicals)
- Aripiprazole, Asenapine, Brexpiprazole, Cariprazine, Clozapine, Iloperidone, Lurasidone, Olanzapine, Paliperidone, Pimavanserin, Quetiapine, Risperidone, Ziprasidone