Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Non-sedating H1 antihistamine

Fexofenadine hydrochloride

Brand names: Telfast, Allevia

Fexofenadine is a non-sedating (second-generation) antihistamine used for allergic rhinitis and chronic urticaria.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Directions do not divide, crush, chew or dissolve the tablet; swallow tablet whole adults and children 12 years of age and over take 1 tablet with a glass of water every 12 hours on an empty stomach; do not take more than 2 tablets in 24 hours children under 12 years of age do not use adults 65 years of age and older ask a doctor consumers with kidney disease ask a doctor

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2018-05-31. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

It is a selective peripheral histamine H1-receptor antagonist with minimal central penetration, so it is essentially non-sedating.

Prescribing in practice

  • It is among the least sedating antihistamines.
  • Absorption is reduced by some fruit juices and by aluminium/magnesium antacids — separate their timing.
  • It is not a treatment for anaphylaxis, which requires adrenaline and emergency care.

Monitoring

Review symptom control; no routine monitoring.

Counselling the patient

  • It is non-drowsy for most people.
  • Avoid taking it at the same time as fruit juice or indigestion remedies.
  • It does not treat severe allergic reactions, which need emergency care.

Evidence & guidelines

A non-sedating antihistamine for allergic rhinitis and chronic urticaria.

Reference: BSACI urticaria guideline; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Pathways