Clinical studies of promethazine hydrochloride and dextromethorphan hydrobromide oral solution did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.
Sedating drugs may cause confusion and over-sedation in the elderly; elderly patients generally should be started on low doses of promethazine hydrochloride and dextromethorphan hydrobromide oral solution and observed closely.
Dextromethorphan hydrobromide occasionally causes slight drowsiness, dizziness, and gastrointestinal disturbances.
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.
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.
According to the WHO Expert Committee on Drug Dependence, dextromethorphan could produce very slight psychic dependence but no physical dependence.
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.
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.
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.
The average effective dose is given in the following table:
|Adults||1 teaspoonful (5 mL) every 4 to 6 hours, not to exceed 30 mL in 24 hours.|
|Children 6 Years To Under 12 Years||½ to 1 teaspoonful (2.5 to 5 mL) every 4 to 6 hours, not to exceed 20 mL in 24 hours.|
|Children 2 Years To Under 6 Years||¼ to ½ teaspoonful (1.25 to 2.5 mL) every 4 to 6 hours, not to exceed 10 mL in 24 hours.|
NDC: 50090-0225-0 118 mL in a BOTTLE
Chestnut Ridge, NY 10977
|PROMETHAZINE DM dextromethorphan hydrobromide and promethazine hydrochloride solution|
|Labeler — A-S Medication Solutions (830016429)|
|A-S Medication Solutions||830016429||RELABEL (50090-0225)|
Revised: 01/2020 A-S Medication Solutions
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