DOSAGE AND ADMINISTRATION Important Administration Information for Adult and Pediatric Patients 2 Years of Age and Older The preferred route of administration of PHENERGAN Injection is by deep intramuscular administration (see WARNINGS - Severe Tissue Injury, Including Gangrene ). PHENERGAN Injection may be administered intravenously after dilution as recommended below (see Preparation and Administration ). If pain occurs at the injection site during intravenous infusion, immediately discontinue the infusion, and evaluate for possible arterial injection or perivascular extravasation. Allergic Conditions The average adult dose is 25 mg. This dose may be repeated within two hours if necessary, but continued therapy, if indicated, should be via the oral route as soon as existing circumstances permit. After initiation of treatment, dosage should be adjusted to the smallest amount adequate to relieve symptoms. The average adult dose for amelioration of allergic reactions to blood or plasma is 25 mg. Sedation In hospitalized adult patients, nighttime sedation may be achieved by a dose of 25 to 50 mg of PHENERGAN Injection. Nausea and Vomiting For control of nausea and vomiting, the usual adult dose is 12.5 to 25 mg, not to be repeated more frequently than every four hours. When used for control of postoperative nausea and vomiting, the dosage of analgesics and barbiturates should be reduced accordingly (see PRECAUTIONS - Drug Interactions ). Antiemetics should not be used in vomiting of unknown etiology in children and adolescents (see PRECAUTIONS - Pediatric Use ). Preoperative and Postoperative Use As an adjunct to preoperative or postoperative medication, 25 to 50 mg of PHENERGAN Injection in adults may be combined with appropriately reduced doses of analgesics and atropine-like drugs as desired. Dosage of concomitant analgesic or hypnotic medication should be reduced accordingly (see PRECAUTIONS - Drug Interactions ). PHENERGAN Injection is contraindicated for use in pediatric patients less than two years of age. Obstetrics PHENERGAN Injection in doses of 50 mg will provide sedation and relieve apprehension in the early stages of labor. When labor is definitely established, 25 to 75 mg (average dose, 50 mg) PHENERGAN Injection may be given with an appropriately reduced dose of any desired narcotic (see PRECAUTIONS - Drug Interactions ). If necessary, PHENERGAN Injection with a reduced dose of analgesic may be repeated once or twice at four-hour intervals in the course of a normal labor. A maximum total dose of 100 mg of PHENERGAN Injection may be administered during a 24-hour period to patients in labor. Pediatric Patients PHENERGAN Injection is contraindicated for use in pediatric patients less than 2 years of age (see WARNINGS - Respiratory Depression ). Caution should be exercised when administering promethazine hydrochloride to pediatric patients 2 years of age or older. It is recommended that the lowest effective dose of promethazine hydrochloride be used in pediatric patients 2 years of age and older and concomitant administration of other drugs with respiratory depressant effects be avoided (see WARNINGS - Respiratory Depression ). In pediatric patients 2 years of age and older, the dosage should not exceed half that of the suggested adult dose. As an adjunct to premedication, the suggested dose is 1.1 mg per kg of body weight in combination with an appropriately reduced dose of narcotic or barbiturate and the appropriate dose of an atropine-like drug (see PRECAUTIONS - Drug Interactions ). Antiemetics should not be used in vomiting of unknown etiology in pediatric patients. Preparation and Administration Instructions for Diluted Intravenous Infusion in Adults Inspect the solution for particulate matter and discoloration, before dilution, after dilution, and before administration. Discard the vial, ampule, or bag if particulates and/or discoloration are observed. 1. Determine the recommended dose of promethazine hydrochloride injection. 2. Aseptically withdraw the required volume from the vial or ampule and transfer it into an infusion bag. Use a filter needle when withdrawing promethazine hydrochloride injection from the ampule. 3. Dilute with the recommended volume of 0.9% Sodium Chloride Injection, see Table 1. Avoid mixing and/or diluting with any other drugs or solutions other than 0.9% Sodium Chloride Injection. 4. Gently invert the infusion bag. 5. Check patency of the access site before administration. 6. Administer the diluted solution through an intravenous catheter, inserted in a large vein (preferably through a central venous catheter), over 20 to 40 minutes; for maximum infusion rates, see Table 1. Do NOT administer via an intravenous catheter in the hand or wrist. 7. If pain occurs at the injection site during intravenous infusion, immediately discontinue the infusion and evaluate for possible arterial injection or perivascular extravasation. Table 1. Preparation and Infusion Information by Adult Dose of PHENERGAN Injection Dose of PHENERGAN Injection Volume of 0.9% Sodium Chloride Injection for Dilution Maximum Concentration of the Diluted PHENERGAN Injection Solution Maximum Rate of Infusion 12.5 mg 50 mL 1 mg/mL 2.5 mL/minute 25 mg 50 mL 2.5 mL/minute 50 mg 50 mL 2.5 mL/minute 75 mg 100 mL 5 mL/minute Preparation and Administration Instructions for Diluted Intravenous Infusion to Pediatric Patients 2 Years of Age and Older Inspect the solution for particulate matter and discoloration, before dilution, after dilution, and before administration. Discard the vial, ampule, syringe or bag if particulates and/or discoloration are observed. 1. Determine the recommended dose of promethazine hydrochloride injection for pediatric patients 2 years of age and older. 2. Aseptically withdraw the required volume from the vial or ampule and transfer it into an appropriately sized syringe or bag for use with an infusion pump. Use a filter needle when withdrawing promethazine hydrochloride injection from the ampule. 3. Dilute with the recommended volume of 0.9% Sodium Chloride Injection, see Table 2. Avoid mixing and/or diluting with any other drugs or solutions other than 0.9% Sodium Chloride Injection. 4. Gently invert the syringe or bag. 5. Check patency of the access site before administration. 6. Administer the diluted solution through an intravenous catheter, inserted in a large vein (preferably through a central venous catheter) with a maximum infusion rate of 1.25 mL/minute. Do NOT administer via an intravenous catheter in the hand or wrist. 7. If pain occurs at the injection site during intravenous infusion, immediately discontinue the infusion and evaluate for possible arterial injection or perivascular extravasation. Table 2. Preparation and Infusion Information by Pediatric Dose of PHENERGAN Injection Avoid mixing and/or diluting with any other drugs or solutions besides 0.9% Sodium Chloride Injection Dose of PHENERGAN Injection Volume of 0.9% Sodium Chloride Injection for Dilution Maximum Concentration of the Diluted PHENERGAN Injection Solution Maximum Rate of Infusion Up to 25 mg 25 mL 1 mg/mL 1.25 mL/minute 25 mg to 50 mg 50 mL Storage of Diluted PHENERGAN Injection Diluted solution may be stored up to 4 hours at room temperature, 20°C to 25°C (68°F to 77°F), or refrigerated at 2°C to 8°C (36° to 46°F), up to 24 hours.