1. Clinical Overview
A fixed-dose combination (FDC) syrup for symptomatic relief of productive and non-productive cough associated with upper respiratory tract infections. It combines an expectorant (Guaifenesin), a mucolytic (Bromhexine), an antihistamine (Diphenhydramine), an expectorant/acidifier (Ammonium Chloride), and a soothing agent (Menthol). This combination is widely used in the Indian market for its multi-modal action on cough reflex, mucus viscosity, and airway irritation.
| Onset | Duration | Bioavailability |
|---|---|---|
| Guaifenesin/Bromhexine/Ammonium Chloride: 30-60 minutes. Diphenhydramine: 15-30 minutes. | Guaifenesin/Bromhexine/Ammonium Chloride: 4-6 hours. Diphenhydramine: 4-8 hours. | Guaifenesin: ~45-60%. Bromhexine: ~20-30%. Diphenhydramine: ~40-60%. Ammonium Chloride: Rapidly absorbed. Menthol: Topical/local effect. |
2. Mechanism of Action
This combination works synergistically. Guaifenesin increases respiratory tract fluid secretions and reduces mucus viscosity. Bromhexine depolymerizes mucopolysaccharide fibers in sputum, decreasing viscosity and aiding expectoration. Diphenhydramine acts centrally on the medullary cough center to suppress the cough reflex and peripherally as an H1-antagonist to reduce post-nasal drip. Ammonium Chloride acts as an expectorant by irritating the gastric mucosa, leading to a reflex increase in bronchial secretions; it also acidifies urine. Menthol provides a cooling sensation and mild local anesthetic effect on the throat, soothing irritation.
3. Indications & Uses
- Symptomatic relief of productive (wet) cough with thick, tenacious mucus
- Symptomatic relief of non-productive (dry, irritating) cough
- Cough associated with acute bronchitis
- Cough associated with tracheobronchitis
4. Dosage & Administration
Adult Dosage: 10 ml (2 teaspoonfuls) three to four times a day. Maximum: 40 ml per day.
Administration: Take orally. Use the measuring cup/spoon provided. Can be taken with or without food. Taking with a full glass of water may enhance the expectorant effect of Guaifenesin and Ammonium Chloride. Do not drive or operate machinery for 6-8 hours after a dose.
5. Side Effects
Common side effects may include:
- Drowsiness, sedation
- Dryness of mouth, nose, and throat
- Dizziness
- Gastrointestinal upset (nausea, epigastric discomfort)
- Thickening of bronchial secretions (paradoxical)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Alcohol, Benzodiazepines, Opioids, other CNS Depressants | Additive CNS depression, sedation, and impaired psychomotor performance. | Major |
| MAO Inhibitors (e.g., Phenelzine, Selegiline) | Increased anticholinergic effects (dry mouth, blurred vision, urinary retention, hyperpyrexia). | Major |
| Anticholinergic drugs (e.g., Atropine, Tricyclic Antidepressants, Antipsychotics) | Additive anticholinergic side effects. | Moderate |
| Drugs metabolized by CYP2D6 (e.g., Codeine, Metoprolol, Venlafaxine) | Diphenhydramine is a CYP2D6 inhibitor; may increase levels of these drugs. | Moderate |
| Urinary Alkalinizers (e.g., Sodium Bicarbonate, Acetazolamide) | Decrease renal excretion of Diphenhydramine, increasing its levels and effects. | Moderate |
| Sympathomimetics (e.g., Ephedrine, Pseudoephedrine) | Diphenhydramine may potentiate pressor effects. | Moderate |
7. Patient Counselling
- DO use the measuring device provided for accurate dosing.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DO inform your doctor about all other medicines you are taking.
- DO drink plenty of fluids to help loosen mucus.
- DO NOT exceed the prescribed dose or frequency.
- DO NOT consume alcohol while on this medication.
- DO NOT drive, operate machinery, or perform hazardous tasks while taking this medicine.
- DO NOT give to children under 2 years without doctor's advice.
- DO NOT use for chronic cough associated with smoking, asthma, or emphysema without diagnosis.
8. Toxicology & Storage
Overdose: Anticholinergic Toxidrome: Severe dry mouth, dilated pupils (mydriasis), flushing, hyperthermia, tachycardia, hypertension followed by hypotension, urinary retention, decreased GI motility, agitation, hallucinations, seizures, coma, respiratory depression, and cardiac arrest.
Storage: Store at room temperature (15-30°C), protected from light and moisture. Keep the bottle tightly closed. Keep out of reach and sight of children. Do not use after the expiry date printed on the label. Do not freeze.