A fixed-dose combination (FDC) medication used for the symptomatic relief of cough and cold. It combines an expectorant (Guaifenesin), a centrally-acting antitussive (Dextromethorphan), and a second-generation antihistamine (Cetirizine). This combination addresses productive cough, dry cough, and allergic symptoms like rhinorrhea and sneezing commonly seen in upper respiratory tract infections (URTI) and allergic rhinitis. It is widely prescribed in India for acute, self-limiting conditions.
Adult: One tablet/capsule twice daily. Maximum: 2 doses in 24 hours.
Note: Administer orally with a full glass of water. Can be taken with or without food. Taking with food may reduce potential gastric upset. Do not crush or chew sustained-release formulations. Maintain adequate hydration to aid Guaifenesin's expectorant action.
This combination works synergistically on different pathways of the cough reflex and allergic response. Guaifenesin increases respiratory tract fluid secretions and reduces mucus viscosity, facilitating expectoration. Dextromethorphan elevates the cough threshold in the central cough center in the medulla oblongata. Cetirizine competitively inhibits histamine at the H1-receptor site, reducing allergic symptoms like nasal congestion, sneezing, and rhinorrhea.
Pregnancy: Category B2 (Australian) / Not formally assigned by US FDA. Guaifenesin: Limited data, avoid in first trimester. Dextromethorphan: Crosses placenta; some studies show possible risk. Cetirizine: Limited human data, animal studies not suggestive of risk. USE ONLY IF CLEARLY NEEDED AND UNDER MEDICAL SUPERVISION. Avoid in first trimester.
Driving: May impair alertness, reaction time, and motor coordination. Advise patients not to drive or operate heavy machinery until their individual response is known, especially during initial therapy.
| Monoamine Oxidase Inhibitors (MAOIs) - Phenelzine, Selegiline | Risk of severe serotonin syndrome, hyperpyrexia, and death. | Contraindicated |
| Selective Serotonin Reuptake Inhibitors (SSRIs) - Fluoxetine, Paroxetine | Increased risk of serotonin syndrome due to CYP2D6 inhibition and additive serotonergic effects. | Major |
| Other CNS Depressants (Alcohol, Benzodiazepines, Opioids) | Additive CNS depression, increased sedation, impaired alertness. | Major |
| Anticholinergic drugs (Atropine, Tricyclic Antidepressants) | Potentiated anticholinergic effects (dry mouth, urinary retention, constipation). | Moderate |
| CYP2D6 Inhibitors (Quinidine, Bupropion) | Increased Dextromethorphan plasma levels, leading to increased effects and toxicity. | Moderate |
| Theophylline | Cetirizine may slightly decrease the clearance of Theophylline. | Minor |
Same composition (Guaifenesin (100mg) + Dextromethorphan Hydrobromide (10mg) + Cetirizine (5mg)), different brands: