Telfast

Telfast is a 2nd-generation oral antihistamine containing Fexofenadine as its active ingredient, available in 60, 120, and 180 mg strengths. Manufactured by Sanofi.

Fexofenadine works by blocking H1 Histamine Receptors, which trigger allergy symptoms such as sneezing, runny nose, nasal itching, congestion, itchy/watery eyes, and hives. By blocking H1 receptors, these symptoms are reduced.

Fexofenadine's key advantage is that it does not cross the Blood-Brain Barrier (BBB), meaning it does not cause drowsiness — unlike first-generation antihistamines (Chlorpheniramine, Diphenhydramine) that cross the BBB and cause significant sedation, and unlike Cetirizine which, despite being second-generation, may still cause some drowsiness.

Allergic Rhinitis: Relieves sneezing, runny nose, nasal congestion, itchy nose, itchy/watery eyes caused by allergens such as dust, pollen, dust mites, and pet dander.

Chronic Urticaria: Relieves itching, hives, and red raised welts.

Recommended dosages:

• Allergic Rhinitis — 120 mg or 180 mg once daily
• Chronic Urticaria — 180 mg once daily
• Mild symptoms — 60 mg twice daily (morning and evening)

Key advantages of Telfast:

• Non-drowsy — suitable for drivers and those needing concentration
• Fast-acting — starts working within 1 hour
• Once daily — convenient dosing

Adults and children 12 years and older:

• Allergic Rhinitis — 120 mg or 180 mg once daily
• Chronic Urticaria — 180 mg once daily

Children 6-11 years: 30 mg twice daily (use liquid formula or 30 mg tablets)

How to take:

• Take with plain water only
• Do NOT take with orange, apple, or grapefruit juice as they significantly reduce absorption
• Can be taken before or after meals
• Take at the same time every day

Kidney disease: Dose reduction required; consult your doctor.

If you miss a dose: Skip the missed dose and take the next one at the usual time. Do not double up.

Possible side effects (very rare):

• Headache
• Nausea
• Dizziness
• Drowsiness (very rare, similar to placebo)

Serious side effects (extremely rare — stop and seek medical attention):

• Severe allergic reaction: rash, hives, swelling of face/lips/throat, difficulty breathing
• Chest tightness, breathing difficulties

Side effect advantages:

• Fexofenadine has the fewest side effects among antihistamines
• Non-sedating, does not impair concentration or reaction time
• No cardiac effects (no QT prolongation, unlike Terfenadine which was withdrawn from the market)

Do not use:

• Allergy to Fexofenadine or any other ingredient

Use with caution:

• Kidney disease — dose reduction required as Fexofenadine is primarily excreted by the kidneys
• Elderly — may need dose adjustment if kidney function is impaired
• Pregnancy — limited safety data; consult doctor before use
• Breastfeeding — may pass into breast milk; consult doctor

Things to avoid:

• Orange, apple, and grapefruit juice — reduce Fexofenadine absorption via OATP transporter, potentially rendering the medication ineffective
• Aluminium/Magnesium antacids — take at least 2 hours apart

Telfast vs. Nasonex: Nasonex is a nasal spray containing Mometasone (corticosteroid), which reduces inflammation directly in the nose. Better for severe nasal congestion than Telfast. Both can be used together — Telfast for sneezing, itching, runny nose, and Nasonex for congestion.

Telfast vs. Cetirizine: Both are 2nd-generation antihistamines with similar efficacy. However, Cetirizine may cause some drowsiness (about 10% of users), while Fexofenadine causes virtually none. Better for drivers and those needing full concentration.

Telfast vs. Loratadine: Both are non-sedating with similar efficacy. Loratadine is slightly cheaper, but Fexofenadine may work faster and has stronger evidence for urticaria treatment.

Orange juice, apple juice, and grapefruit juice contain substances that inhibit OATP (Organic Anion Transporting Polypeptide), a transport protein that helps absorb Fexofenadine from the intestine into the bloodstream.

When OATP is inhibited, Fexofenadine absorption is reduced by up to 36%, potentially lowering blood levels too much for effective allergy treatment.

Recommendations:

• Take Telfast with plain water only
• Wait at least 4 hours after taking before drinking fruit juice
• Other fruit juices (not orange, apple, or grapefruit) are fine

Telfast is a pharmacist-dispensed medication. You can order online from Intimo Life.

Can I buy Telfast online?

Yes. Order through Intimo Life — select the product, consult with a licensed pharmacist online, and receive your medication at home.

Do I need a prescription?

A doctor's prescription is not required, but the medication must be dispensed by a licensed pharmacist. At Intimo Life, our pharmacist will review your symptoms and health history to confirm suitability before shipping.

How does Intimo Life ship orders?

We deliver nationwide in Thailand with discreet packaging — no product names on the outside.