Meddex Méz Ízű (Dextromethorphan)

Dextromethorphan acts on the cough reflex pathway to provide symptomatic relief of cough.

• Dry cough: reduces the frequency and intensity of non‑productive cough in adults and children.
• Cough associated with common cold: alleviates temporary cough symptoms during viral upper respiratory infections.
• Cough due to acute bronchitis: helps control coughing episodes in patients with acute bronchial inflammation.

• Dextromethorphan exerts its antitussive effect primarily by antagonizing NMDA receptors in the medullary cough centre and by acting as a sigma‑1 receptor agonist. This dual action diminishes the sensory input that triggers the cough reflex, leading to reduced cough frequency without significant bronchodilation or anti‑inflammatory activity. Additionally, it modestly inhibits serotonin reuptake, which may contribute to its central effects.

Dextromethorphan may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Nausea: mild stomach upset or queasiness.
• Dizziness: feeling light‑headed or unsteady.
• Drowsiness: increased sleepiness or reduced alertness.
• Dry mouth: reduced salivation leading to a dry throat.
• Constipation: difficulty passing stools.

Serious or Rare Side Effects

• Allergic reactions: rash, itching, swelling, or anaphylaxis.
• Serotonin syndrome: agitation, hyperthermia, tremor when combined with serotonergic agents.
• Hallucinations or psychotic symptoms: visual or auditory disturbances at high doses.
• Severe respiratory depression: markedly slowed breathing, especially with overdose.
• Cardiac arrhythmia: irregular heart rhythm in susceptible individuals.

When considering Dextromethorphan, several safety precautions should be observed to minimize risk.

• Age restriction: avoid use in children younger than 4 years due to risk of respiratory depression.
• Concomitant serotonergic drugs: review use of SSRIs, MAOIs, or tramadol to prevent serotonin syndrome.
• Hepatic impairment: assess liver function and adjust use if severe impairment is present.
• Alcohol consumption: advise patients to limit alcohol as it may enhance central nervous system depression.
• Pregnancy and breastfeeding: use only if the potential benefit outweighs the potential risk to the fetus or infant.
• Store at ambient temperature: keep in the original container, protect from moisture and light.

Dextromethorphan can interact with other medicines; awareness of major and moderate interactions helps ensure safe use.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): concurrent use may precipitate severe serotonin syndrome.
• Selective serotonin reuptake inhibitors (SSRIs) and other serotonergic agents: increased risk of serotonin toxicity.
• Tricyclic antidepressants: additive central nervous system effects and heightened serotonin levels.

Moderate Interactions (Monitor Closely)

• Alcohol: may potentiate drowsiness and dizziness.
• Antihistamines (e.g., diphenhydramine): can increase sedation.
• Opioid analgesics: combined use may lead to enhanced respiratory depression.