Adult: As dextromethorphan hydrobromide: As conventional preparation: 10-20 mg 4 hourly, or 30 mg 6-8 hourly. As extended-release preparation: 60 mg 12 hourly. Max: 120 mg daily. As loz: Suck not more than 12 loz daily. Child: >12 years Same as adult dose.
May be taken with or without food.
emphysema or other conditions where
persistent or chronic cough occurs. Concomitant use or within 14 days of MAOI or SSRI therapy.
Children <12 years.
Patient with history of drug abuse. Children. Treatment with a cough medicine in children (especially under 12 years old) should be considered carefully due to potential risks and limited evidence on efficacy. Pregnancy and lactation.
This drug can cause drowsiness or cognitive function impairment, if affected, do not drive or operate machinery.
Symptoms: Mydriasis, nausea, vomiting, CNS depression, excitations, lethargy, nystagmus, psychomotor hyperactivity, serotonin syndrome, somnolence, dizziness, dysarthria, mental confusion, psychotic disorder, respiratory depression. Management: Supportive and symptomatic treatment. May perform gastric lavage. Naloxone may be effective in reversing toxicity.
Additive CNS effect when used with antihistamines, psychotropics and other CNS depressants. Increased toxic effect when used with potent CYP2D6 enzyme inhibitors (e.g. fluoxetine, paroxetine, quinidine, terbinafine). Potentially Fatal: Increased risk of serotonin syndrome (e.g. hyperpyrexia, hallucinations, gross excitation or coma) when concomitantly used with MAOIs or SSRIs.
Additive CNS effect when used with alcohol.
False positive phencyclidine, opioids and heroin urine drug screen.
Description: Dextromethorphan, a centrally-acting antitussive agent, depresses the medullary cough centre through sigma receptor stimulation, resulting to decreased sensitivity of cough receptors and interruption of cough impulse transmission. Onset: 15-30 minutes. Duration: ≤6 hours. Pharmacokinetics: Absorption: Rapidly absorbed from the gastrointestinal tract. Time to peak plasma concentration: 2-3 hours. Distribution: Widely distributed. Metabolism: Metabolised in the liver via demethylation by CYP2D6 enzyme to dextrorphan (active); undergoes rapid and extensive first-pass metabolism. Excretion: Via urine, as unchanged drug and metabolites. Elimination half-life: 2-4 hours (extensive metabolisers); 24 hours (poor metabolisers).
R05DA09 - dextromethorphan ; Belongs to the class of opium alkaloids and derivatives. Used as cough suppressant.
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