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Ophthalmic H1 antihistamine + mast cell stabiliser

Epinastine hydrochloride

Brand names: Relestat

Epinastine is a topical ocular antihistamine and mast cell stabiliser used to prevent and relieve the itching of allergic conjunctivitis.

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.

Clinical monograph

How it works

It selectively antagonises histamine H1 receptors and stabilises mast cells, reducing histamine release and the ocular signs and symptoms of allergic conjunctivitis.

Prescribing in practice

  • It is for ocular use only and should not be used to treat contact lens-related irritation; lenses should be removed before instillation and reinserted only after an appropriate interval.
  • It is intended to prevent and relieve allergic eye symptoms rather than treat ocular infection, and persistent or worsening symptoms warrant review.
  • Mild transient ocular discomfort or burning can occur on instillation.

Monitoring

Routine laboratory monitoring is not required; review symptom control and ocular tolerance.

Counselling the patient

  • Remove contact lenses before using the drops and wait as advised before reinserting them.
  • Use regularly during the allergy season for best effect.
  • Report any worsening redness, pain or discharge, which may suggest infection.

Evidence & guidelines

Dual-acting topical antihistamine/mast cell stabilisers are well established for allergic conjunctivitis, with use guided by the SPC.

Reference: RCOphth; BSACI; SmPC; 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.

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