A fixed-dose combination (FDC) of a sympathomimetic decongestant (Phenylephrine) and a first-generation alkylamine antihistamine (Triprolidine). It is primarily used for the symptomatic relief of upper respiratory tract conditions associated with allergic rhinitis and the common cold. Phenylephrine acts as a nasal decongestant by vasoconstriction, while Triprolidine blocks histamine H1 receptors, reducing allergic symptoms like sneezing, rhinorrhea, and itching. This combination is widely available in India as an over-the-counter (OTC) medication, though its use is increasingly scrutinized due to the sedative effects of Triprolidine and the availability of newer, non-sedating alternatives.
Adult: One tablet (Phenylephrine 5mg + Triprolidine 2.5mg) every 6 to 8 hours. Maximum: 4 tablets in 24 hours.
Note: Administer orally with or without food. Taking with food may reduce potential gastric irritation. Swallow whole with a glass of water. Do not crush or chew. Avoid taking close to bedtime if sedation is undesirable, though for nocturnal symptoms, the sedative effect may be beneficial.
The combination provides symptomatic relief through two distinct mechanisms. Phenylephrine is a selective alpha-1 adrenergic receptor agonist. It acts on receptors in the vascular smooth muscle of the nasal mucosa, causing vasoconstriction. This reduces blood flow, tissue swelling, and nasal congestion. Triprolidine is a competitive and reversible antagonist of histamine at the H1 receptor. By blocking histamine, it inhibits its effects on capillary dilation, increased permeability, and sensory nerve stimulation, thereby relieving symptoms like sneezing, itching, and rhinorrhea.
Pregnancy: Category C (US FDA). Animal reproduction studies have not been conducted. Use only if clearly needed and potential benefit justifies potential risk to the fetus. Phenylephrine may reduce placental blood flow. Triprolidine has been associated with rare cases of fetal malformations in some studies. Avoid in first trimester. Consultation with an obstetrician is mandatory.
Driving: NOT ADVISABLE. Triprolidine causes significant drowsiness and impairs cognitive and motor functions. Patients should not drive or operate heavy machinery until they know how the drug affects them, typically for at least 12 hours after a dose.
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Tranylcypromine | Risk of severe hypertensive crisis due to potentiation of Phenylephrine's pressor effects. | Contraindicated |
| Beta-blockers (e.g., Propranolol) | Unopposed alpha-adrenergic activity of Phenylephrine can lead to severe hypertension and bradycardia. | Major |
| Other Sympathomimetics (e.g., Pseudoephedrine, in other cold remedies) | Additive pressor and CNS stimulant effects, increasing risk of hypertension and cardiac events. | Major |
| Antihypertensives (e.g., Methyldopa, Clonidine, Diuretics) | Phenylephrine may antagonize the blood pressure-lowering effect. | Moderate |
| CNS Depressants (e.g., Alcohol, Benzodiazepines, Opioids) | Additive sedative effects with Triprolidine, impairing mental and physical abilities. | Major |
| Anticholinergic drugs (e.g., Atropine, Tricyclic Antidepressants, Antipsychotics) | Additive anticholinergic side effects (dry mouth, urinary retention, constipation, blurred vision). | Moderate |
| Digoxin | Triprolidine may mask the signs of digoxin toxicity (nausea, vomiting). | Moderate |