Symptoms:
These include nausea and vomiting, CNS depression, dizziness, dysarthria (slurred speech), myoclonus, nystagmus, somnolence (drowsiness), tremor, excitation, mental confusion, psychotic disorder (psychosis), and respiratory depression.
Management:
Treatment of overdose should be symptomatic and supportive. Gastric lavage may be of use. Naloxone has been used successfully as a specific antagonist to dextromethorphan toxicity in children.
None stated.
Adverse effects are rare, however the following side effects may be associated with dextromethorphan hydrobromide:
Gastrointestinal Disorders
Rare: Gastrointestinal upset
Nervous System Disorders
Rare: Dizziness, drowsiness, mental confusion
Immune System Disorders
Hypersensitivity
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
There is no relevant information additional to that already contained elsewhere in the SmPC or of relevance to the prescriber.
Dextromethorphan hydrobromide is a cough suppressant which has a central action on the cough centre in the medulla. It has no analgesic properties and little sedative activity.
Dextromethorphan
Pharmacotherapeutic group: Cough suppressant
ATC code: R05DA09
Dextromethorphan hydrobromide is well absorbed from the gastrointestinal tract.
Dextromethorphan undergoes rapid and extensive first-pass metabolism in the liver after oral administration. Genetically controlled O-demethylation (CYD2D6) is the main determinant of dextromethorphan pharmacokinetics in human volunteers.
It appears that there are distinct phenotypes for this oxidation process resulting in highly variable pharmacokinetics between subjects. Unmetabolised dextromethorphan, together with the three demethylated morphinan metabolites dextrorphan (also known as 3-hydroxy-N-methylmorphinan), 3- hydroxymorphinan and 3-methoxymorphinan have been identified as conjugated products in the urine.
Dextrorphan, which also has antitussive action, is the main metabolite. In some individuals metabolism proceeds more slowly and unchanged dextromethorphan predominates in the blood and urine.
No special requirements
ADMINISTRATIVE DATA
