Medications: Thorazine^® – chlorpromazine

INDICATION AND USES:

Chlorpromazine is indicated for:

• For the management of manifestations of psychotic disorders.
• 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.

DOSAGE AND ADMINISTRATION

ADULTS

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.

Elderly Patients – In general, dosages in the lower range are sufficient for most elderly patients. Since they appear to be more susceptible to hypotension and neuromuscular reactions, such patients should be observed closely. Dosage should be tailored to the individual, response carefully monitored, and dosage adjusted accordingly. Dosage should be increased more gradually in elderly patients.

Psychotic Disorders – Increase dosage gradually until symptoms are controlled. Maximum improvement may not be seen for weeks or even months. Continue optimum dosage for 2 weeks; then gradually reduce dosage to the lowest effective maintenance level. Daily dosage of 200 mg is not unusual. Some patients require higher dosages (e.g., 800 mg daily is not uncommon in discharged mental patients).

Hospitalized Patients:

Acute Schizophrenic or Manic States – It is recommended that initial treatment be with chlorpromazine hydrochloride injection until patient is controlled. Usually patient becomes quiet and co-operative within 24 to 48 hours and oral doses may be substituted and increased until the patient is calm. 500 mg a day is generally sufficient. While gradual increases to 2,000 mg a day or more may be necessary, there is usually little therapeutic gain to be achieved by exceeding 1,000 mg a day for extended periods. In general, dosage levels should be lower in the elderly, the emaciated and the debilitated.

Less Acutely Disturbed – 25 mg t.i.d. Increase gradually until effective dose is reached – usually 400 mg daily.

Outpatients – 10 mg t.i.d. or q.i.d., or 25 mg b.i.d. or t.i.d.

More Severe Cases – 25 mg t.i.d. After 1 or 2 days, daily dosage may be increased by 20 to 50 mg at semi-weekly intervals until patient becomes calm and cooperative.

Prompt Control of Severe Symptoms – Initial treatment should be with intramuscular chlorpromazine. Subsequent doses should be oral, 25 mg to 50 mg t.i.d.

Nausea and Vomiting– 10 mg to 25 mg q4 to 6h, p.r.n., increased, if necessary.

Presurgical Apprehension– 25 mg to 50 mg, 2 to 3 hours before the operation.

Intractable Hiccups– 25 mg to 50 mg t.i.d. or q.i.d. If symptoms persist for 2 to 3 days, parenteral therapy is indicated.

Acute Intermittent Porphyria– 25 mg to 50 mg t.i.d. or q.i.d. Can usually be discontinued after several weeks, but maintenance therapy may be necessary for some patients.

PEDIATRIC PATIENTS (6 months to 12 years of age)

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.

Severe Behavioral Problems:

Outpatients – Select route of administration according to severity of patient’s condition and increase dosage gradually as required. Oral: ¼ mg/lb body weight q4 to 6h, p.r.n. (e.g., for 40 lb child – 10 mg q4 to 6h).

Hospitalized Patients – As with outpatients, start with low doses and increase dosage gradually. In severe behavior disorders higher dosages (50 mg to 100 mg daily and in older children, 200 mg daily or more) may be necessary. There is little evidence that behavior improvement in severely disturbed mentally retarded patients is further enhanced by doses beyond 500 mg per day.

Nausea and Vomiting– Dosage and frequency of administration should be adjusted according to the severity of the symptoms and response of the patient. The duration of activity following intramuscular administration may last up to 12 hours. Subsequent doses may be given by the same route if necessary. Oral: ¼ mg/lb body weight (e.g., 40 lb child – 10 mg q4 to 6h).

Presurgical Apprehension–¼ mg/lb body weight orally 2 to 3 hours before operation.

SIDE EFFECTS:

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. Drowsiness, usually mild to moderate, may occur, particularly during the first or second week, after which it generally disappears. If troublesome, dosage may be lowered.

• Jaundice: Overall incidence has been low, regardless of indication or dosage. Most investigators conclude it is a sensitivity reaction. Most cases occur between the second and fourth weeks of therapy. The clinical picture resembles infectious hepatitis, with laboratory features of obstructive jaundice, rather than those of parenchymal damage. It is usually promptly reversible on withdrawal of the medication; however, chronic jaundice has been reported. If fever with grippe-like symptoms occurs, appropriate liver studies should be conducted. If tests indicate an abnormality, stop treatment. Liver function tests in jaundice induced by the drug may mimic extrahepatic obstruction; withhold exploratory laparotomy until extrahepatic obstruction is confirmed.
• Hematological Disorders: including agranulocytosis, eosinophilia, leukopenia, hemolytic anemia, aplastic anemia, thrombocytopenic purpura and pancytopenia have been reported.
• Cardiovascular
  • Postural hypotension, simple tachycardia, momentary fainting and dizziness may occur rarely, after the first oral dose. Usually recovery is spontaneous, and symptoms disappear within ½ to 2 hours. Occasionally, these effects may be more severe and prolonged, producing a shock-like condition.
  • EKG CHANGES: Particularly nonspecific, usually reversible Q and T wave distortions–have been observed in some patients receiving phenothiazine tranquilizers, including chlorpromazine. Note: Sudden death, apparently due to cardiac arrest, has been reported.
• CNS Reactions: Neuromuscular reactions include dystonia, motor restlessness, pseudo-parkinsonism and tardive dyskinesia, and appear to be dose-related. They are discussed in the following paragraphs:
  • Dystonia: Class effect: Symptoms of dystonia, prolonged abnormal contractions of muscle groups, may occur in susceptible individuals during the first few days of treatment. An elevated risk of acute dystonia is observed in males and younger age groups.
  • Motor Restlessness: Symptoms may include agitation or jitteriness and sometimes insomnia. These symptoms often disappear spontaneously. At times these symptoms may be similar to the original neurotic or psychotic symptoms. Dosage should not be increased until these side effects have subsided.
  • Pseudo-parkinsonism: Symptoms may include: mask-like facies, drooling, tremors, pillrolling motion, cogwheel rigidity and shuffling gait. In most cases, these symptoms are readily controlled when an anti-parkinsonism agent is administered concomitantly. Anti-parkinsonism agents should be used only when required. Generally, therapy of a few weeks to 2 or 3 months will suffice. After this time, patients should be evaluated to determine their need for continued treatment. (Note: Levodopa has not been found effective in antipsychotic-induced pseudo-parkinsonism.) Occasionally it is necessary to lower the dosage of chlorpromazine or to discontinue the drug.
  • Tardive Dyskinesia: As with all antipsychotic agents, tardive dyskinesia may appear in some patients on long-term therapy or may appear after drug therapy has been discontinued. The syndrome can also develop, although much less frequently, after relatively brief treatment periods at low doses. This syndrome appears in all age groups. Although its prevalence appears to be highest among elderly patients, especially elderly women, it is impossible to rely upon prevalence estimates to predict at the inception of antipsychotic treatment which patients are likely to develop the syndrome. The symptoms are persistent and, in some patients, appear to be irreversible. The syndrome is characterized by rhythmical involuntary movements of the tongue, face, mouth or jaw (e.g., protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of extremities. In rare instances, these involuntary movements of the extremities are the only manifestations of tardive dyskinesia. A variant of tardive dyskinesia, tardive dystonia, has also been described.
  • Adverse Behavioral Effects – Psychotic symptoms and catatonic-like states have been reported rarely.
• OTHER CNS EFFECTS: Neuroleptic Malignant Syndrome (NMS) has been reported in association with antipsychotic drugs. (See WARNINGS.) Cerebral edema has been reported. Convulsive seizures (petit mal and grand mal) have been reported, particularly in patients with EEG abnormalities or history of such disorders. Abnormality of the cerebrospinal fluid proteins has also been reported.
• Allergic Reactions of a mild urticarial type or photosensitivity are seen. Avoid undue exposure to sun. More severe reactions, including exfoliative dermatitis and toxic epidermal necrolysis (TEN), have been reported occasionally. Contact dermatitis has been reported in nursing personnel; accordingly, the use of rubber gloves when administering chlorpromazine liquid or injectable is recommended.
• In addition, asthma, laryngeal edema, angioneurotic edema and anaphylactoid reactions have been reported.
• Endocrine Disorders: Lactation and moderate breast engorgement may occur in females on large doses. If persistent, lower dosage or withdraw drug. False-positive pregnancy tests have been reported but are less likely to occur when a serum test is used. Amenorrhea and gynecomastia have also been reported. Hyperglycemia, hypoglycemia and glycosuria have been reported.
• Autonomic Reactions: Occasional dry mouth; nasal congestion; nausea; obstipation; constipation; adynamic ileus; urinary retention; priapism; miosis and mydriasis; atonic colon; ejaculatory disorders/impotence.
• Special Considerations in Long-Term Therapy: Skin pigmentation and ocular changes have occurred in some patients taking substantial doses of chlorpromazine for prolonged periods.
• Other Adverse Reactions: Mild fever may occur after large IM doses. Hyperpyrexia has been reported. Increases in appetite and weight sometimes occur. Peripheral edema and a systemic lupus erythematosus-like syndrome have been reported.
• Note: There have been occasional reports of sudden death in patients receiving phenothiazines. In some cases, the cause appeared to be cardiac arrest or asphyxia due to failure of the cough reflex.

DRUG INTERACTIONS:

Not stated