A fixed-dose combination (FDC) of a sympathomimetic decongestant (Pseudoephedrine), a first-generation sedating antihistamine (Chlorpheniramine Maleate), and a centrally-acting antitussive (Dextromethorphan Hydrobromide). It is primarily used for the symptomatic relief of cough and cold, providing decongestion, reduction of allergic symptoms, and suppression of non-productive cough. The combination is widely used in India, though its FDC status has been under regulatory scrutiny.
Adult: Typically: 10 ml syrup or 1 tablet (containing Pseudoephedrine 60 mg, Chlorpheniramine Maleate 4 mg, Dextromethorphan HBr 15 mg) every 6-8 hours. Maximum: 4 doses in 24 hours. Always follow specific brand prescribing information.
Note: Oral administration. Syrup: Use measuring cup/spoon. Can be taken with or without food. Taking with food may reduce GI upset. Maintain adequate fluid intake. Do not crush or chew sustained-release formulations (if any).
The combination provides multi-modal symptomatic relief. Pseudoephedrine acts as a decongestant by stimulating alpha-adrenergic receptors in the nasal mucosa, causing vasoconstriction and reduced edema. Chlorpheniramine is a competitive H1-histamine receptor antagonist, reducing allergic symptoms like rhinorrhea and sneezing, with significant CNS penetration causing sedation. Dextromethorphan suppresses the cough reflex by acting on the medullary cough center, primarily via NMDA receptor antagonism and sigma-1 receptor agonism.
Pregnancy: Category C (US FDA). Pseudoephedrine: Possible risk of gastroschisis in first trimester; avoid in first trimester. Use only if potential benefit justifies potential risk. Avoid near term due to potential effects on fetal circulation.
Driving: NOT ADVISABLE. The combination, particularly Chlorpheniramine, can cause significant drowsiness and dizziness. Patients should not drive or operate heavy machinery until their response is known.
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Selegiline | Risk of severe hypertensive crisis, hyperpyrexia. Contraindicated. | High |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive CNS depression, impaired alertness, respiratory depression. | High |
| Beta-blockers (e.g., Propranolol) | Unopposed alpha-adrenergic effects of Pseudoephedrine can lead to severe hypertension and bradycardia. | High |
| Antihypertensives (e.g., Methyldopa, Clonidine) | Pseudoephedrine may antagonize the hypotensive effect. | Moderate |
| Serotonergic Drugs (SSRIs, SNRIs, TCAs, Tramadol) | Increased risk of serotonin syndrome due to Dextromethorphan's weak SERT inhibition. | Moderate |
| CYP2D6 Inhibitors (e.g., Fluoxetine, Paroxetine, Quinidine) | Markedly increased Dextromethorphan levels, leading to toxicity and CNS effects. | Moderate |
| Anticholinergic Drugs (e.g., Atropine, TCAs, Antipsychotics) | Additive anticholinergic side effects (dry mouth, urinary retention, confusion). | Moderate |