A fixed-dose combination syrup containing a first-generation alkylamine antihistamine (Chlorpheniramine Maleate) and a non-opioid antitussive (Dextromethorphan Hydrobromide). It is primarily indicated for the symptomatic relief of dry, non-productive cough associated with upper respiratory tract infections, allergic conditions, and common cold. Chlorpheniramine provides anti-allergic and anti-secretory effects, while Dextromethorphan acts centrally to suppress the cough reflex.
Adult: 10 ml (2 teaspoonfuls) three to four times daily. Maximum: 40 ml per day.
Note: To be taken orally. Use the measuring cup or spoon provided. Can be taken with or without food. Shake the bottle well before use.
Chlorpheniramine competitively antagonizes histamine at the H1-receptor, inhibiting histamine-mediated symptoms like rhinorrhea, sneezing, and itching. It also possesses anticholinergic and sedative properties. Dextromethorphan is a d-isomer of the codeine analog, levorphanol. It acts centrally on the cough center in the medulla oblongata to raise the threshold for coughing. Its action is mediated through NMDA receptor antagonism and sigma-1 receptor agonism, not through opioid mu receptors, hence it is non-narcotic.
Pregnancy: Category B (US FDA). Chlorpheniramine is generally considered safe but should be used only if clearly needed. Dextromethorphan: Epidemiological studies show no clear evidence of risk. Use during the first trimester should be avoided unless benefit outweighs risk. Consult a physician.
Driving: NOT ADVISABLE. Can cause significant drowsiness, dizziness, and blurred vision, impairing the ability to drive or operate machinery.
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Selegiline | Risk of severe serotonin syndrome, hyperpyrexia, excitation, hypertension. | Contraindicated |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids, Sedative Antipsychotics) | Additive CNS depression, impaired alertness, respiratory depression. | Major |
| Selective Serotonin Reuptake Inhibitors (SSRIs) - e.g., Fluoxetine, Paroxetine | Increased dextromethorphan levels and risk of serotonin syndrome. | Major |
| Tricyclic Antidepressants (TCAs) - e.g., Amitriptyline | Additive anticholinergic effects (dry mouth, constipation, urinary retention) and CNS depression. | Moderate |
| Anticholinergic drugs (e.g., Atropine, Oxybutynin) | Additive anticholinergic side effects. | Moderate |
| CYP2D6 Inhibitors (e.g., Quinidine, Cinacalcet) | Increased dextromethorphan levels, converting extensive metabolizers to poor metabolizer phenotype. | Moderate |
| CYP3A4 Inducers (e.g., Rifampicin, Carbamazepine) | Decreased dextromethorphan levels, reduced efficacy. | Moderate |