A fixed-dose combination (FDC) oral liquid primarily indicated for the symptomatic relief of cough and associated symptoms of upper respiratory tract infections (URTI) and allergic conditions. It combines a decongestant (Phenylephrine), a first-generation sedating antihistamine (Chlorpheniramine), and a centrally-acting antitussive (Dextromethorphan). This combination is widely used in the Indian OTC market for managing symptoms of the common cold, allergic rhinitis, and non-productive cough. Its use is typically short-term.
Adult: 10 ml (2 teaspoonfuls) three to four times a day. Maximum: 40 ml per day.
Note: To be taken orally. Use the measuring cup or spoon provided. Can be taken with or without food. Taking with food may reduce potential gastric irritation. Do not exceed the recommended dosage. Maintain adequate fluid intake. Shake the bottle well before use.
This combination provides symptomatic relief through three distinct mechanisms: 1) Phenylephrine acts as a selective alpha-1 adrenergic receptor agonist, causing vasoconstriction in the nasal mucosa, reducing blood flow and edema, leading to decongestion. 2) Chlorpheniramine is a competitive inverse agonist at peripheral and central H1 receptors, inhibiting the effects of histamine, thereby reducing allergic symptoms like rhinorrhea, sneezing, and itching. Its central action causes sedation. 3) Dextromethorphan and its active metabolite dextrorphan act centrally on the cough center in the medulla oblongata, raising the threshold for cough reflex, likely through NMDA receptor antagonism and sigma-1 receptor agonism.
Pregnancy: Category C (US FDA). Not recommended, especially in the first trimester. Use only if potential benefit justifies potential risk to the fetus. Phenylephrine may reduce placental blood flow. Chlorpheniramine has been associated with rare teratogenic effects (cleft palate).
Driving: NOT ADVISABLE. Chlorpheniramine causes significant drowsiness and impairs cognitive and motor skills. Patients should not drive or operate machinery until effect is known.
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Selegiline | Risk of severe hypertensive crisis, hyperpyrexia. Contraindicated. | Contraindicated |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids, Barbiturates) | Additive CNS depression, impaired alertness, respiratory depression. | Major |
| Other Anticholinergic Drugs (Tricyclic Antidepressants, Antipsychotics, Antiparkinsonian drugs) | Additive anticholinergic effects (dry mouth, urinary retention, constipation, confusion). | Major |
| Beta-blockers (e.g., Propranolol) | Unopposed alpha-adrenergic stimulation by Phenylephrine can lead to severe hypertension and bradycardia. | Major |
| Serotonergic Drugs (SSRIs, SNRIs, TCAs, Tramadol) | Increased risk of serotonin syndrome due to Dextromethorphan's serotonergic activity. | Major |
| CYP2D6 Inhibitors (e.g., Fluoxetine, Paroxetine, Quinidine) | Increased Dextromethorphan levels, decreased dextrorphan levels, altering antitussive effect and increasing risk of CNS side effects. | Moderate |
| CYP3A4 Inhibitors (e.g., Ketoconazole, Clarithromycin) | Increased levels of Chlorpheniramine and Dextromethorphan (via 3-methoxymorphinan pathway), increasing sedation and side effects. | Moderate |
| Antihypertensives | Phenylephrine may antagonize the blood pressure-lowering effect. | Moderate |
| Digoxin | Chlorpheniramine may mask the signs of digoxin toxicity (nausea, vomiting). | Moderate |
Same composition (Phenylephrine (5mg/5ml) + Chlorpheniramine Maleate (2mg/5ml) + Dextromethorphan Hydrobromide (10mg/5ml)), different brands: