Phenergan Injection Dosage
Medically reviewed by Drugs.com. Last updated on Apr 19, 2022.
Important Notes on Administration
PHENERGAN Injection can cause severe chemical irritation and damage to tissues regardless of the route of administration. Irritation and damage can result from perivascular extravasation, unintentional intra-arterial injection, and intraneuronal or perineuronal infiltration (see WARNINGS - Severe Tissue Injury, Including Gangrene).
- The preferred parenteral route of administration for PHENERGAN Injection is by deep intramuscular injection.
- Under no circumstances should PHENERGAN Injection be given by intra-arterial injection due to the likelihood of severe arteriospasm and the possibility of resultant gangrene (see WARNINGS - Severe Tissue Injury, Including Gangrene).
- Subcutaneous injection is contraindicated as it may result in tissue necrosis.
- When administered intravenously, PHENERGAN Injection should be given in a concentration no greater than 25 mg per mL and at a rate not to exceed 25 mg per minute. It is preferable to inject through the tubing of an intravenous infusion set that is known to be functioning satisfactorily.
- In the event that a patient complains of pain during intravenous injection of PHENERGAN Injection, the injection should be stopped immediately to evaluate for possible arterial injection or perivascular extravasation.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Do not use PHENERGAN Injection if solution has developed color or contains precipitate.
To avoid the possibility of physical and/or chemical incompatibility, consult specialized literature before diluting with any injectable solution or combining with any other medication. Do not use if there is a precipitate or any sign of incompatibility.
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.
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 is contraindicated for use in pediatric patients less than two years of age.
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.
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.
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