Promethazine Hydrochloride
Promethazine Hydrochloride Prescribing Information
Promethazine hydrochloride tablets, USP are useful for:
Perennial and seasonal allergic rhinitis.
Vasomotor rhinitis.
Allergic conjunctivitis due to inhalant allergens and foods.
Mild, uncomplicated allergic skin manifestations of urticaria and angioedema.
Amelioration of allergic reactions to blood or plasma.
Dermographism.
Anaphylactic reactions, as adjunctive therapy to epinephrine and other standard measures, after the acute manifestations have been controlled.
Preoperative, postoperative, or obstetric sedation.
Prevention and control of nausea and vomiting associated with certain types of
anesthesia and surgery.
Therapy adjunctive to meperidine or other analgesics for control of post-operative pain.
Sedation in both children and adults, as well as relief of apprehension and production of light sleep from which the patient can be easily aroused.
Active and prophylactic treatment of motion sickness.
Antiemetic therapy in postoperative patients.
WARNING: PROMETHAZINE HYDROCHLORIDE TABLETS, USP SHOULD NOT BE USED IN PEDIATRIC PATIENTS LESS THAN 2 YEARS OF AGE BECAUSE OF THE POTENTIAL FOR FATAL RESPIRATORY DEPRESSION. POSTMARKETING CASES OF RESPIRATORY DEPRESSION, INCLUDING FATALITIES, HAVE BEEN REPORTED WITH USE OF PROMETHAZINE HYDROCHLORIDE TABLETS, USP IN PEDIATRIC PATIENTS LESS THAN 2 YEARS OF AGE. A WIDE RANGE OF WEIGHT-BASED DOSES OF PROMETHAZINE HYDROCHLORIDE TABLETS, USP HAVE RESULTED IN RESPIRATORY DEPRESSION IN THESE PATIENTS. CAUTION SHOULD BE EXERCISED WHEN ADMINISTERING PROMETHAZINE HYDROCHLORIDE TABLETS, USP TO PEDIATRIC PATIENTS 2 YEARS OF AGE AND OLDER. IT IS RECOMMENDED THAT THE LOWEST EFFECTIVE DOSE OF PROMETHAZINE HYDROCHLORIDE TABLETS, USP BE USED IN PEDIATRIC PATIENTS 2 YEARS OF AGE AND OLDER AND CONCOMITANT ADMINISTRATION OF OTHER DRUGS WITH RESPIRATORY DEPRESSANT EFFECTS BE AVOIDED. |
Promethazine hydrochloride tablets, USP may impair the mental and/or physical abilities required for the performance of potentially hazardous tasks, such as driving a vehicle or operating machinery. The impairment may be amplified by concomitant use of other central-nervous-system depressants such as alcohol, sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers; therefore such agents should either be eliminated or given in reduced dosage in the presence of promethazine hydrochloride (see
Promethazine hydrochloride tablets, USP may lead to potentially fatal respiratory depression.
Use of promethazine hydrochloride tablets, USP in patients with compromised respiratory function (e.g., COPD, sleep apnea) should be avoided.
Promethazine hydrochloride tablets, USP may lower seizure threshold. It should be used with caution in persons with seizure disorders or in persons who are using concomitant medications, such as narcotics or local anesthetics, which may also affect seizure threshold.
Promethazine hydrochloride tablets, USP should be used with caution in patients with bone-marrow depression. Leukopenia and agranulocytosis have been reported, usually when promethazine hydrochloride tablets, USP have been used in association with other known marrow-toxic agents.
A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant
Syndrome (NMS) has been reported in association with promethazine hydrochloride alone or in combination with antipsychotic drugs. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis and cardiac dysrhythmias).
The diagnostic evaluation of patients with this syndrome is complicated. In arriving at a diagnosis, it is important to identify cases where the clinical presentation includes both serious medical illness (e.g. pneumonia, systemic infection, etc.) and untreated or inadequately treated extrapyramidal signs and symptoms (EPS). Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever and primary central nervous system (CNS) pathology.
The management of NMS should include 1) immediate discontinuation of promethazine hydrochloride, antipsychotic drugs, if any, and other drugs not essential to concurrent therapy, 2) intensive symptomatic treatment and medical monitoring, and 3) treatment of any concomitant serious medical problems for which specific treatments are available. There is no general agreement about specific pharmacological treatment regimens for uncomplicated NMS.
Since recurrences of NMS have been reported with phenothiazines, the reintroduction of promethazine hydrochloride should be carefully considered.
Excessively large dosages of antihistamines, including promethazine hydrochloride tablets, USP, in pediatric patients may cause sudden death (see
Administration of promethazine hydrochloride has been associated with reported cholestatic jaundice.
Promethazine hydrochloride tablets, USP are for oral administration only.
The average oral dose is 25 mg taken before retiring; however, 12.5 mg may be taken before meals and on retiring, if necessary. Single 25 mg doses at bedtime or 6.25 mg to 12.5 mg taken three times daily will usually suffice. After initiation of treatment in children or adults, dosage should be adjusted to the smallest amount adequate to relieve symptoms. The administration of promethazine hydrochloride in 25 mg doses will control minor transfusion reactions of an allergic nature.
The average adult dose is 25 mg taken twice daily. The initial dose should be taken one-half to one hour before anticipated travel and be repeated 8 to 12 hours later, if necessary. On succeeding days of travel, it is recommended that 25 mg be given on arising and again before the evening meal. For children, promethazine hydrochloride tablets, USP 12.5 mg to 25 mg, twice daily, may be administered.
Antiemetics should not be used in vomiting of unknown etiology in children and adolescents (see
The average effective dose of promethazine hydrochloride tablets, USP for the active therapy of nausea and vomiting in children or adults is 25 mg. 12.5 to 25 mg doses may be repeated, as necessary, at 4 to 6 hour intervals.
For nausea and vomiting in children, the usual dose is 0.5 mg per pound of body weight, and the dose should be adjusted to the age and weight of the patient and the severity of the condition being treated.
For prophylaxis of nausea and vomiting, as during surgery and the postoperative period, the average dose is 25 mg repeated at 4 to 6 hour intervals, as necessary.
This product relieves apprehension and induces a quiet sleep from which the patient can be easily aroused. Administration of 12.5 to 25 mg promethazine hydrochloride orally at bedtime will provide sedation in children. Adults usually require 25 to 50 mg for nighttime, presurgical, or obstetrical sedation.
Promethazine hydrochloride tablets, USP in 12.5 to 25 mg doses for children and 50 mg doses for adults the night before surgery relieves apprehension and produces a quiet sleep.
For preoperative medication, children require doses of 0.5 mg per pound of body weight in combination with an appropriately reduced dose of narcotic or barbiturate and the appropriate dose of an atropine-like drug. Usual adult dosage is 50 mg promethazine hydrochloride tablets, USP with an appropriately reduced dose of narcotic or barbiturate and the required amount of a belladonna alkaloid.
Postoperative sedation and adjunctive use with analgesics may be obtained by the administration of 12.5 to 25 mg in children and 25 to 50 mg doses in adults.
Promethazine hydrochloride tablets, USP are contraindicated for children under 2 years of age.
Promethazine hydrochloride tablets, USP are contraindicated for use in pediatric patients less than two years of age.
Promethazine hydrochloride tablets, USP are contraindicated in comatose states, and in individuals known to be hypersensitive or to have had an idiosyncratic reaction to promethazine or to other phenothiazines.
Antihistamines are contraindicated for use in the treatment of lower respiratory tract symptoms including asthma.
Drowsiness is the most prominent CNS effect of this drug. Sedation, somnolence, blurred vision, dizziness; confusion, disorientation, and extrapyramidal symptoms such as oculogyric crisis, torticollis, and tongue protrusion; lassitude, tinnitus, incoordination, fatigue, euphoria, nervousness, diplopia, insomnia, tremors, convulsive seizures, excitation, catatonic-like states, hysteria. Hallucinations have also been reported.
faintness.
agranulocytosis.
Hyperexcitability and abnormal movements have been reported in patients following a single administration of promethazine hydrochloride. Consideration should be given to the discontinuation of promethazine hydrochloride and to the use of other drugs if these reactions occur. Respiratory depression, nightmares, delirium, and agitated behavior have also been reported in some of these patients.
Each 12.5 mg promethazine hydrochloride tablet for oral administration contains 12.5 mg promethazine hydrochloride.
Each 25 mg promethazine hydrochloride tablet for oral administration contains 25 mg promethazine hydrochloride.
Each 50 mg promethazine hydrochloride tablet for oral administration contains 50 mg promethazine hydrochloride.
Each tablet contains the following inactive ingredients: lactose monohydrate, magnesium stearate, and methylcellulose.
In addition, 50 mg tablet contains FD&C Red #40 and 12.5 mg tablet contains FD&C Yellow #6.
Promethazine hydrochloride is a racemic compound; the empirical formula is C
17H
20N
2S•HCl and its molecular weight is 320.88.
Promethazine hydrochloride, a phenothiazine derivative, is designated chemically as 10

Promethazine hydrochloride occurs as a white to faint yellow, practically odorless, crystalline powder which slowly oxidizes and turns blue on prolonged exposure to air. It is freely soluble in water and soluble in alcohol.