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. Increase parenteral dosage only if hypotension has not occurred. Before using IM, see IMPORTANT NOTES ON INJECTION. 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 IM: 25 mg (1 mL). If necessary, give additional 25 to 50 mg injection in 1 hour. Increase subsequent IM doses gradually over several days–up to 400 mg q4-6h in exceptionally severe cases–until patient is controlled. Usually the patient becomes quiet and cooperative within 24 to 48 hours and oral doses may be substituted. Prompt Control of Severe Symptoms IM: 25 mg (1 mL). If necessary, repeat in 1 hour. Subsequent doses should be oral, 25-50 mg tid. NAUSEA AND VOMITING IM: 25 mg (1 mL). If no hypotension occurs, give 25 to 50 mg q3-4h prn, until vomiting stops. Then switch to oral dosage. During Surgery IM: 12.5 mg (0.5 mL). Repeat in 1/2 hour if necessary and if no hypotension occurs. IV: 2 mg per fractional injection, at 2-minute intervals. Do not exceed 25 mg. Dilute to 1 mg/mL, i.e., 1 mL (25 mg) mixed with 24 mL of saline. PRESURGICAL APPREHENSION IM: 12.5 to 25 mg (0.5-1 mL), 1 to 2 hours before operation. INTRACTABLE HICCUPS If symptoms persist for 2-3 days after trial with oral therapy, give 25 to 50 mg (1-2 mL) IM. Should symptoms persist, use slow IV infusion with patient flat in bed: 25 to 50 mg (1-2 mL) in 500 to 1000 mL of saline. Follow blood pressure closely. ACUTE INTERMITTENT PORPHYRIA IM: 25 mg (1 mL) tid or qid until patient can take oral therapy. TETANUS IM: 25 to 50 mg (1-2 mL) given 3 or 4 times daily, usually in conjunction with barbiturates. Total doses and frequency of administration must be determined by the patient’s response, starting with low doses and increasing gradually. IV: 25 to 50 mg (1-2 mL). Dilute to at least 1 mg per mL and administer at a rate of 1 mg per minute. 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. IM: 1/4 mg/lb body weight q6-8h, prn. Hospitalized Patients As with outpatients, start with low doses and increase dosage gradually. In severe behavior disorders, higher dosages (50-100 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. Maximum IM Dosage: Patients up to 5 years (or 50 lbs.), not over 40 mg/day; 5-12 years (or 50-100 lbs.), not over 75 mg/day except in unmanageable cases. 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. IM: 1/4 mg/lb body weight q6-8h, prn. Maximum IM Dosage: Pediatric patients 6 months to 5 years (or 50 lbs.), not over 40 mg/day; 5-12 years (or 50-100 lbs.), not over 75 mg/day except in severe cases. During Surgery IM: 1/8 mg/lb body weight. Repeat in 1/2 hour if necessary and if no hypotension occurs. IV: 1 mg per fractional injection at 2-minute intervals and not exceeding recommended IM dosage. Always dilute to 1 mg/mL, i.e., 1 mL (25 mg) mixed with 24 mL of saline. PRESURGICAL APPREHENSION 1/4 mg/lb body weight IM 1 to 2 hours before operation. TETANUS IM or IV: 1/4 mg/lb body weight q6-8h. When given IV, dilute to at least 1 mg/mL and administer at a rate of 1 mg per 2 minutes. In patients up to 50 lbs., do not exceed 40 mg daily; 50 to 100 lbs., do not exceed 75 mg except in severe cases. Important Notes on Injection Inject slowly, deep into upper outer quadrant of buttock. Because of possible hypotensive effects, reserve parenteral administration for bedfast patients or for acute ambulatory cases, and keep patient lying down for at least 1/2 hour after injection. If irritation is a problem, dilute injection with saline or 2% procaine; mixing with other agents in the syringe is not recommended. Subcutaneous injection is not advised. AVOID INJECTING UNDILUTED CHLORPROMAZINE HYDROCHLORIDE INJECTION INTO VEIN. IV ROUTE IS ONLY FOR SEVERE HICCUPS, SURGERY AND TETANUS. Because of the possibility of contact dermatitis, avoid getting solution on hands or clothing. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.