Promethazine Dm Drug Information

Promethazine hydrochloride and dextromethorphan hydrobromide oral solution is indicated for the temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold.

• Dextromethorphan: Dextromethorphan hydrobromide occasionally causes slight drowsiness, dizziness, and gastrointestinal disturbances.
• Promethazine: 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 – Promethazine ; Respiratory Depression.) Other – Angioneurotic edema. Neuroleptic malignant syndrome (potentially fatal) has also been reported. (See WARNINGS – Promethazine ; Neuroleptic Malignant Syndrome.) Paradoxical Reactions – Hyperexcitability and abnormal movements have been reported in patients following a single administration of promethazine HCl. Consideration should be given to the discontinuation of promethazine HCl 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 Dextromethorphan: Hyperpyrexia, hypotension, and death have been reported coincident with the coadministration of monoamine oxidase (MAO) inhibitors and products containing dextromethorphan. Thus, concomitant administration of promethazine with dextromethorphan and MAO inhibitors should be avoided (see CONTRAINDICATIONS ).
• Promethazine: CNS Depressants – Promethazine may increase, prolong, or intensify the sedative action 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 be avoided or administered in reduced dosage to patients receiving promethazine HCl. When given concomitantly with promethazine, 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 promethazine HCl 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 to reverse epinephrine's vasopressor effect, epinephrine should NOT be used to treat hypotension associated with promethazine overdose. Anticholinergics – Concomitant use of other agents with anticholinergic properties should be undertaken with caution. Monoamine Oxidase Inhibitors (MAOI) – Drug interactions, including an increased incidence of extrapyramidal effects, have been reported when some MAOI and phenothiazines are used concomitantly.

• 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 of promethazine HCl. These doses are from approximately 2.1 to 4.2 times the maximum recommended total daily dose of promethazine for a 50-kg subject, depending upon the indication for which the drug is prescribed. Daily doses of 25 mg/kg intraperitoneally have been found to produce fetal mortality in rats. Specific studies to test the action of the drug on parturition, lactation, and development of the animal neonate were not done, but a general preliminary study in rats indicated no effect on these parameters. Although antihistamines have been found to produce fetal mortality in rodents, the pharmacological effects of histamine in the rodent do not parallel those in man. There are no adequate and well-controlled studies of promethazine in pregnant women. Promethazine and dextromethorphan should be used during pregnancy only if the potential benefit justifies the risk to the fetus.
• Nonteratogenic Effects: Promethazine administered to a pregnant woman within two weeks of delivery may inhibit platelet aggregation in the newborn.

Pediatric Use PROMETHAZINE HYDROCHLORIDE AND DEXTROMETHORPHAN HYDROBROMIDE ORAL SOLUTION IS CONTRAINDICATED FOR USE IN PEDIATRIC PATIENTS LESS THAN TWO YEARS OF AGE (see WARNINGS – Black Box Warning and Use In Pediatric Patients ). Promethazine hydrochloride and dextromethorphan hydrobromide oral solution should be used with caution in pediatric patients 2 years of age and older (see WARNINGS – Use In Pediatric Patients ).

Dextromethorphan should not be used in patients receiving a monoamine oxidase inhibitor (MAOI) (see PRECAUTIONS, Drug Interactions ). Promethazine is 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.

• Dextromethorphan: Dextromethorphan may produce central excitement and mental confusion. Very high doses may produce respiratory depression. One case of toxic psychosis (hyperactivity, marked visual and auditory hallucinations) after ingestion of a single dose of 20 tablets (300 mg) of dextromethorphan has been reported.
• Promethazine: Signs and symptoms of overdosage with promethazine HCl 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 children and geriatric patients. Convulsions may rarely occur. A paradoxical reaction has been reported in children 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, as well as gastrointestinal symptoms, may occur.
• Treatment: The treatment of overdosage with promethazine and dextromethorphan 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. Activated charcoal orally or by lavage may be given, or sodium or magnesium sulfate orally as a cathartic. Attention should be given to the re-establishment 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. The antidotal efficacy of narcotic antagonists to dextromethorphan has not been established; note that any of the depressant effects of promethazine are not reversed by naloxone. Avoid analeptics, which may cause convulsions. Severe hypotension usually responds to the administration of norepinephrine or phenylephrine. EPINEPHRINE SHOULD NOT BE USED, since its use in a patient with partial adrenergic blockage may further lower the blood pressure. Limited experience with dialysis indicates that it is not helpful.