ASTHAFEN

1. Introduction

Asthafen is a brand name for ketotifen, a unique dual-action medication with both antihistamine and mast cell stabilizing properties. It’s primarily used for:

• Prophylaxis of asthma

• Allergic rhinitis

• Allergic conjunctivitis

• Chronic urticaria

2. Description

• Generic Name: Ketotifen fumarate

• Brand Names: Asthafen (India), Zaditen (international)

• Dosage Forms:

  • Tablets (1 mg)

  • Syrup (1 mg/5 mL)

  • Eye drops (0.025%)

• Manufacturer: Sun Pharma (Asthafen brand)

3. Key Features

✔ Mast cell stabilizer – prevents release of histamine ✔ H1-antihistamine – blocks histamine receptors ✔ Anti-eosinophilic activity ✔ Oral and ophthalmic formulations available

4. Mechanism of Action

• Mast cell stabilization: Inhibits release of histamine, leukotrienes, and other mediators

• H1-receptor blockade: Competitively antagonizes histamine H1 receptors

• Reduces eosinophil chemotaxis

• May upregulate β-adrenergic receptors

5. Therapeutic Uses

Main Indications:

• Prophylaxis of mild-to-moderate asthma (especially allergic asthma)

• Allergic rhinoconjunctivitis

• Atopic dermatitis (adjunct therapy)

• Chronic urticaria

Off-label Uses:

• Mastocytosis

• Food allergy prophylaxis

• Eosinophilic esophagitis

6. Dosage

Adults:

• Initial: 1 mg twice daily

• Maintenance: May reduce to 1 mg daily

Children (>3 years):

• 0.5-1 mg twice daily (max 2 mg/day)

Special Populations:

• Elderly: Start with lower doses

• Renal/hepatic impairment: Dose adjustment may be needed

7. Side Effects

Common:

• Sedation (drowsiness in 10-20% patients)

• Dry mouth

• Weight gain (5-10% patients)

• Dizziness

Less Common:

• Increased appetite

• Nausea

• Headache

• Paradoxical irritability (in children)

Rare but Serious:

• Seizures (lower threshold)

• Blood dyscrasias

• Severe hypersensitivity

8. Storage

• Store below 30°C

• Protect from light and moisture

• Syrup: Use within 1 month after opening

9. Precautions & Warnings

⚠ Sedation: May impair alertness (caution when driving) ⚠ Weight gain: Monitor BMI regularly ⚠ Seizure disorders: May lower seizure threshold ⚠ Pregnancy: Category C (use only if benefits outweigh risks) ⚠ Breastfeeding: Excreted in milk (avoid)

10. Drug Interactions

• CNS depressants: Enhanced sedation (alcohol, benzodiazepines) • MAO inhibitors: Increased anticholinergic effects • Antiepileptics: May alter seizure threshold • Theophylline: Reduced ketotifen levels

11. Advantages

• Prophylactic action (takes 4-12 weeks for full effect)

• Dual mechanism (both preventive and symptomatic relief)

• Pediatric-friendly formulations

• Cost-effective compared to newer alternatives

12. Clinical Pearls

• Therapeutic lag: Clinical improvement typically seen after 2-4 weeks • Best taken at bedtime due to sedative effects • Not for acute asthma attacks (only prophylaxis) • Combination therapy: Often used with inhaled corticosteroids

13. Conclusion

Asthafen remains a valuable option for allergic asthma prophylaxis and chronic allergic conditions, particularly in resource-limited settings. While it requires long-term use for full benefits, its dual mechanism and cost-effectiveness make it a practical choice for many patients.