Phenergan Drug Information

Respiratory Depression PHENERGAN Injection is contraindicated in pediatric patients less than 2 years of age, because of the potential for fatal respiratory depression. PHENERGAN Injection should be used with caution in pediatric patients 2 years of age and older (see WARNINGS - Respiratory Depression ). Severe Tissue Injury, Including Gangrene PHENERGAN Injection has been reported to cause severe chemical irritation and damage to tissues, including gangrene, regardless of the route of parenteral administration. Intra-arterial and subcutaneous injection have resulted in more significant complications (see CONTRAINDICATIONS ). Reported adverse reactions included burning, pain, erythema, swelling, sensory loss, palsies, paralysis, severe spasm of distal vessels, thrombophlebitis, venous thrombosis, phlebitis, abscesses, tissue necrosis, and gangrene (see WARNINGS - Severe Tissue Injury, Including Gangrene ). Central Nervous System 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. Cardiovascular Increased or decreased blood pressure, tachycardia, bradycardia, faintness.

Dermatologic Dermatitis, photosensitivity, urticaria. Hematologic Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis. Gastrointestinal Dry mouth, nausea, vomiting, jaundice.

Respiratory Asthma, nasal stuffiness, respiratory depression (potentially fatal) and apnea (potentially fatal). (See WARNINGS - Respiratory Depression.) Other Angioneurotic edema. Neuroleptic Malignant Syndrome (potentially fatal) has also been reported. (See WARNINGS - Neuroleptic Malignant Syndrome.) Paradoxical Reactions Hyperexcitability and abnormal movements have been reported in patients following a single administration of PHENERGAN Injection. Consideration should be given to the discontinuation of PHENERGAN Injection 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.

Drug Interactions CNS Depressants PHENERGAN Injection may increase, prolong, or intensify the sedative action of central-nervous-system depressants, such as alcohol, sedative/hypnotics (including barbiturates), general anesthetics, narcotics, narcotic analgesics, tricyclic antidepressants, and tranquilizers; therefore, such agents should be avoided or administered in reduced dosage to patients receiving promethazine hydrochloride. When given concomitantly with PHENERGAN Injection, the dose of barbiturates should be reduced by at least one-half, and the dose of narcotics should be reduced by one-quarter to one-half. Dosage must be individualized.

Excessive amounts of PHENERGAN Injection relative to a narcotic may lead to restlessness and motor hyperactivity in the patient with pain; these symptoms usually disappear with adequate control of the pain. Epinephrine Because of the potential for promethazine hydrochloride to reverse epinephrine’s vasopressor effect, epinephrine should NOT be used to treat hypotension associated with PHENERGAN Injection overdose. Anticholinergics Concomitant use of other agents with anticholinergic properties should be undertaken with caution.

Monoamine Oxidase (MAO) Inhibitors Drug interactions, including an increased incidence of extrapyramidal effects, have been reported when some MAO Inhibitors and phenothiazines are used concomitantly. This possibility should be considered with PHENERGAN Injection.

Pregnancy Teratogenic Effects—Pregnancy Category C Teratogenic effects have not been demonstrated in rat-feeding studies at doses of 6.25 and 12.5 mg/kg (approximately 2.1 and 4.2 times the maximum recommended human daily dose) of PHENERGAN Injection. Daily doses of 25 mg/kg intraperitoneally have been found to produce fetal mortality in rats. There are no adequate and well-controlled studies of PHENERGAN Injection in pregnant women.

Because animal reproduction studies are not always predictive of human response, PHENERGAN Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Adequate studies to determine the action of the drug on parturition, lactation and development of the animal neonate have not been conducted. Nonteratogenic Effects PHENERGAN Injection administered to a pregnant woman within two weeks of delivery may inhibit platelet aggregation in the newborn.

Pediatric Use PHENERGAN Injection is contraindicated for use in pediatric patients less than 2 years of age, because of the potential for fatal respiratory depression. PHENERGAN Injection should be used with caution in pediatric patients 2 years of age and older (see WARNINGS - Respiratory Depression ). Antiemetics are not recommended for treatment of uncomplicated vomiting in pediatric patients, and their use should be limited to prolonged vomiting of known etiology. The extrapyramidal symptoms which can occur secondary to PHENERGAN Injection administration may be confused with the CNS signs of undiagnosed primary disease, e.g. encephalopathy or Reye’s syndrome.

The use of PHENERGAN Injection should be avoided in pediatric patients whose signs and symptoms may suggest Reye’s syndrome or other hepatic diseases. Excessively large dosages of antihistamines, including PHENERGAN Injection, in pediatric patients may cause sudden death (see OVERDOSAGE ). Hallucinations and convulsions have occurred with therapeutic doses and overdoses of PHENERGAN Injection in pediatric patients. In pediatric patients who are acutely ill associated with dehydration, there is an increased susceptibility to dystonias with the use of PHENERGAN Injection.

The use of PHENERGAN Injection is contraindicated: In pediatric patients less than 2 years of age due to the risk of respiratory depression (see WARNINGS – Respiratory Depression ). For use as an intravenous injection at concentrations greater than 1 mg/mL due to the risk of perivascular extravasation, unintentional intra-arterial injection, and intraneuronal or perineuronal infiltration (see WARNINGS - Severe Tissue Injury, Including Gangrene and DOSAGE AND ADMINISTRATION ). For use as an intra-arterial injection due to the likelihood of severe arteriospasm and the possibility of resultant gangrene (see WARNINGS - Severe Tissue Injury, Including Gangrene ). For use as a subcutaneous injection because chemical irritation and necrotic lesions have been reported (see WARNINGS - Severe Tissue Injury, Including Gangrene ). In patients in a comatose state. In patients who have demonstrated an idiosyncratic reaction or hypersensitivity to promethazine hydrochloride or other phenothiazines.

Signs and symptoms of overdosage range from mild depression of the central nervous system and cardiovascular system to profound hypotension, respiratory depression, unconsciousness and sudden death. Other reported reactions include hyperreflexia, hypertonia, ataxia, athetosis, and extensor-plantar reflexes (Babinski reflex). Stimulation may be evident, especially in pediatric patients and geriatric patients. Convulsions may rarely occur.

A paradoxical-type reaction has been reported in pediatric patients receiving single doses of 75 mg to 125 mg orally, characterized by hyperexcitability and nightmares. Atropine-like signs and symptoms-dry mouth; fixed, dilated pupils; flushing; etc., as well as gastrointestinal symptoms, may occur. Treatment Treatment of overdosage is essentially symptomatic and supportive.

Only in cases of extreme overdosage or individual sensitivity do vital signs, including respiration, pulse, blood pressure, temperature, and EKG, need to be monitored. Attention should be given to the reestablishment of adequate respiratory exchange through provision of a patent airway and institution of assisted or controlled ventilation. Diazepam may be used to control convulsions.

Acidosis and electrolyte losses should be corrected. Note that any depressant effects of PHENERGAN Injection are not reversed by naloxone. Avoid analeptics, which may cause convulsions.

The treatment of choice for resulting hypotension is administration of intravenous fluids, accompanied by repositioning if indicated. In the event that vasopressors are considered for the management of severe hypotension which does not respond to intravenous fluids and repositioning, the administration of norepinephrine or phenylephrine should be considered. EPINEPHRINE SHOULD NOT BE USED, since its use in a patient with partial adrenergic blockade may further lower the blood pressure.

Extrapyramidal reactions may be treated with anticholinergic antiparkinson agents, diphenhydramine, or barbiturates. Oxygen may also be administered. Limited experience with dialysis indicates that it is not helpful.