Chlorpromazine hydrochloride, a phenothiazine derivative, has a chemical formula of 2-chloro-10-[3(-dimethylamino) propyl] phenothiazine monohydochloride. It has the following structural formula:

Each tablet for oral administration contains 10 mg, 25 mg, 50 mg, 100 mg, or 200 mg of chlorpromazine HCl, USP. Inactive ingredients: acacia, black iron oxide, calcium sulfate, carnauba wax, D&C Yellow #10 Aluminum Lake, FD&C Blue #2 Aluminum Lake, FD&C Yellow #6 Aluminum Lake, anhydrous lactose, magnesium stearate, methylparaben, pharmaceutical glaze, povidone, propylparaben, sodium benzoate, sucrose and titanium dioxide.
The precise mechanism whereby the therapeutic effects of chlorpromazine are produced is not known. The principal pharmacological actions are psychotropic. It also exerts sedative and antiemetic activity. Chlorpromazine has actions at all levels of the central nervous system – primarily at subcortical levels – as well as on multiple organ systems. Chlorpromazine has strong antiadrenergic and weaker peripheral anticholinergic activity; ganglionic blocking action is relatively slight. It also possesses slight antihistaminic and antiserotonin activity.
For the treatment of schizophrenia.
To control nausea and vomiting.
For relief of restlessness and apprehension before surgery.
For acute intermittent porphyria.
As an adjunct in the treatment of tetanus.
To control the manifestations of the manic type of manic-depressive illness.
For relief of intractable hiccups.
For the treatment of severe behavioral problems in children (1 to 12 years of age) marked by combativeness and/or explosive hyperexcitable behavior (out of proportion to immediate provocations), and in the short-term treatment of hyperactive children who show excessive motor activity with accompanying conduct disorders consisting of some or all of the following symptoms: impulsivity, difficulty sustaining attention, aggressivity, mood lability and poor frustration tolerance.
Do not use in patients with known hypersensitivity to phenothiazines.
Do not use in comatose states or in the presence of large amounts of central nervous system depressants (alcohol, barbiturates, narcotics, etc.).
The extrapyramidal symptoms which can occur secondary to chlorpromazine may be confused with the central nervous system signs of an undiagnosed primary disease responsible for the vomiting, e.g., Reye's syndrome or other encephalopathy. The use of chlorpromazine and other potential hepatotoxins should be avoided in children and adolescents whose signs and symptoms suggest Reye's syndrome.
Given the likelihood that some patients exposed chronically to antipsychotics will develop tardive dyskinesia, it is advised that all patients in whom chronic use is contemplated be given, if possible, full information about this risk. The decision to inform patients and/or their guardians must obviously take into account the clinical circumstances and the competency of the patient to understand the information provided.
Chlorpromazine should be administered cautiously to persons with cardiovascular, liver or renal disease. There is evidence that patients with a history of hepatic encephalopathy due to cirrhosis have increased sensitivity to the CNS effects of chlorpromazine (i.e., impaired cerebration and abnormal slowing of the EEG).
Because of its CNS depressant effect, chlorpromazine should be used with caution in patients with chronic respiratory disorders such as severe asthma, emphysema and acute respiratory infections, particularly in children (1 to 12 years of age).
Because chlorpromazine can suppress the cough reflex, aspiration of vomitus is possible.
Chlorpromazine prolongs and intensifies the action of CNS depressants such as anesthetics, barbiturates and narcotics. When chlorpromazine is administered concomitantly, about ¼ to ½ the usual dosage of such agents is required. When chlorpromazine is not being administered to reduce requirements of CNS depressants, it is best to stop such depressants before starting chlorpromazine treatment. These agents may subsequently be reinstated at low doses and increased as needed.
Note: Chlorpromazine does not intensify the anticonvulsant action of barbiturates. Therefore, dosage of anticonvulsants, including barbiturates, should not be reduced if chlorpromazine is started. Instead, start chlorpromazine at low doses and increase as needed.
Use with caution in persons who will be exposed to extreme heat, organophosphorus insecticides, and in persons receiving atropine or related drugs.
Antipsychotic drugs elevate prolactin levels; the elevation persists during chronic administration. Tissue culture experiments indicate that approximately 1/3 of human breast cancers are prolactin-dependent in vitro, a factor of potential importance if the prescribing of these drugs is contemplated in a patient with a previously detected breast cancer. Although disturbances such as galactorrhea, amenorrhea, gynecomastia and impotence have been reported, the clinical significance of elevated serum prolactin levels is unknown for most patients. An increase in mammary neoplasms has been found in rodents after chronic administration of antipsychotic drugs. Neither clinical nor epidemiologic studies conducted to date, however, have shown an association between chronic administration of these drugs and mammary tumorigenesis; the available evidence is considered too limited to be conclusive at this time.
Chromosomal aberrations in spermatocytes and abnormal sperm have been demonstrated in rodents treated with certain antipsychotics.
As with all drugs which exert an anticholinergic effect, and/or cause mydriasis, chlorpromazine should be used with caution in patients with glaucoma.
Chlorpromazine diminishes the effect of oral anticoagulants.
Phenothiazines can produce alpha-adrenergic blockade. Chlorpromazine may lower the convulsive threshold; dosage adjustments of anticonvulsants may be necessary. Potentiation of anticonvulsant effects does not occur. However, it has been reported that chlorpromazine may interfere with the metabolism of phenytoin and thus precipitate phenytoin toxicity.
Concomitant administration with propranolol results in increased plasma levels of both drugs.
Thiazide diuretics may accentuate the orthostatic hypotension that may occur with phenothiazines.
The presence of phenothiazines may produce false-positive phenylketonuria (PKU) test results.
Drugs which lower the seizure threshold, including phenothiazine derivatives, should not be used with metrizamide. As with other phenothiazine derivatives, chlorpromazine should be discontinued at least 48 hours before myelography, should not be resumed for at least 24 hours postprocedure, and should not be used for the control of nausea and vomiting occurring either prior to myelography or postprocedure with metrizamide.
Note: Some adverse effects of chlorpromazine may be more likely to occur, or occur with greater intensity, in patients with special medical problems, e.g., patients with mitral insufficiency or pheochromocytoma have experienced severe hypotension following recommended doses.
Adjust dosage to individual and the severity of his condition, recognizing that the milligram for milligram potency relationship among all dosage forms has not been precisely established clinically. It is important to increase dosage until symptoms are controlled. Dosage should be increased more gradually in debilitated or emaciated patients. In continued therapy, gradually reduce dosage to the lowest effective maintenance level, after symptoms have been controlled for a reasonable period.
The 100 mg and 200 mg tablets are for use in severe neuropsychiatric conditions.
Chlorpromazine should generally not be used in pediatric patients under 6 months of age except where potentially lifesaving. It should not be used in conditions for which specific pediatric dosages have not been established.
(See also ADVERSE REACTIONS)
Chlorpromazine Hydrochloride Tablets, USP, are available in bottles of 100 and 1000 as follows:
THESE TABLET STRENGTHS LISTED BELOW ARE FOR USE ONLY IN SEVERE NEUROPSYCHIATRIC CONDITIONS:
Store at controlled room temperature 15 – 30° C (59 – 86° F). Protect from light and moisture.
This package is not for household dispensing. Dispense in a well closed, light-resistant container as defined in the USP.
Keep out of reach of children.
Rx only
Rev. 07-03
15085-08
Manufactured by:
UPSHER-SMITH LABORATORIES, INC.
Minneapolis, MN 55447