Allegra AF

Cetirizine (5mg) + Paracetamol (325mg) + Phenylephrine (10mg)
Price: ₹45 - ₹65 for 10 tablets strip
Mfr: Sanofi India Limited | Form: Tablet

📋 Clinical Overview

A fixed-dose combination (FDC) medication containing a second-generation antihistamine (Cetirizine), an analgesic-antipyretic (Paracetamol), and a decongestant (Phenylephrine). It is primarily indicated for the symptomatic relief of allergic rhinitis and the common cold, addressing sneezing, rhinorrhea, nasal congestion, headache, body ache, and fever. The combination provides comprehensive relief from upper respiratory symptoms. The FDC was approved by the Indian regulatory authorities (CDSCO) for specific symptomatic relief, though its rationality is sometimes debated in clinical circles.

💊 Dosage & Administration

Adult: One tablet every 8 to 12 hours. Maximum: 3 tablets in 24 hours.

Note: Take with or without food. Swallow whole with a glass of water. Do not crush or chew. Can be taken after meals to minimize potential gastric discomfort from Paracetamol. Maintain adequate hydration.

⚠️ Contraindications

  • Hypersensitivity to Cetirizine, Paracetamol, Phenylephrine or any component
  • Severe hypertension
  • Severe coronary artery disease
  • Patients on MAO inhibitor therapy (or within 14 days of discontinuation)
  • Severe hepatic impairment (Child-Pugh C)

🔬 Mechanism of Action

The combination works synergistically: Cetirizine competitively antagonizes histamine at peripheral H1 receptors, inhibiting allergic response. Paracetamol inhibits central cyclooxygenase (COX), particularly COX-2 in the brain, reducing prostaglandin synthesis involved in pain and fever. Phenylephrine acts as a selective alpha-1 adrenergic receptor agonist, causing vasoconstriction in the nasal mucosa, reducing edema and congestion.

🤕 Side Effects

  • Drowsiness
  • Dry mouth
  • Headache
  • Mild dizziness
  • Fatigue
  • Nausea
  • Constipation

🤰 Special Populations

Pregnancy: Category B (Cetirizine, Phenylephrine) / Category A (Paracetamol in 1st/2nd trimester, Category C in 3rd). Use only if clearly needed. Avoid in first trimester unless benefit outweighs risk. Paracetamol is preferred analgesic/antipyretic. Phenylephrine should be avoided, especially in the 1st and 3rd trimesters due to theoretical risk of reduced uterine blood flow and teratogenicity.

Driving: May impair ability to drive or operate machinery. Cetirizine can cause drowsiness and dizziness, especially during initial therapy or with alcohol. Patients should not drive until their individual response is known.

🔄 Drug Interactions

Monoamine Oxidase Inhibitors (e.g., Phenelzine, Selegiline)Risk of severe hypertensive crisis due to Phenylephrine.Contraindicated
Other sympathomimetics (e.g., Pseudoephedrine, Decongestant nasal sprays)Additive pressor effects, increasing risk of hypertension and tachycardia.Major
CNS Depressants (e.g., Alcohol, Benzodiazepines, Opioids)Increased sedative effect of Cetirizine.Moderate
Antihypertensives (Beta-blockers, Alpha-blockers, Diuretics)Phenylephrine may antagonize hypotensive effect.Moderate
Drugs inducing liver enzymes (e.g., Rifampicin, Carbamazepine, Phenytoin)Increased risk of Paracetamol hepatotoxicity due to enhanced toxic metabolite (NAPQI) formation.Moderate
WarfarinChronic high-dose Paracetamol may potentiate anticoagulant effect; monitor INR.Moderate
Anticholinergics (e.g., Atropine, Tricyclic Antidepressants)Additive anticholinergic effects (dry mouth, urinary retention, blurred vision).Moderate

🔁 Alternatives to Allegra AF

Same composition (Cetirizine (5mg) + Paracetamol (325mg) + Phenylephrine (10mg)), different brands:

Cetrizine P Coldamine Plus Zincet Cold Histafree Plus