Fexofenadine 120mg / 180mg Tablets

How it works

It is a selective peripheral histamine H1-receptor antagonist (the active metabolite of terfenadine) that blocks histamine-mediated allergic responses with little central nervous system penetration.

Prescribing in practice

• It is substantially less sedating than older antihistamines, making it preferable when drowsiness must be minimised, though individuals may still occasionally be affected.
• Absorption is reduced by aluminium- and magnesium-containing antacids and by certain fruit juices, which should be separated from the dose.
• The higher tablet strength is generally reserved for chronic urticaria rather than routine allergic rhinitis, per the SPC.

Monitoring

Routine monitoring is not required; review symptom control and tolerability at follow-up.

Counselling the patient

• It is usually non-drowsy, but take care driving until you know how it affects you.
• Avoid taking it at the same time as indigestion remedies or fruit juice.
• It can be taken regularly during your allergy season for best control.

Evidence & guidelines

Non-sedating antihistamines such as fexofenadine are recommended first-line for allergic rhinitis in UK and international (ARIA) guidance.