Homatropine hydrobromide

How it works

It competitively blocks muscarinic receptors on the iris sphincter and ciliary muscle, producing pupil dilatation and temporary paralysis of accommodation, which also helps relieve ciliary spasm and prevent posterior synechiae in uveitis.

Prescribing in practice

• It may precipitate an acute rise in intraocular pressure in eyes with a narrow anterior chamber angle, so caution is needed in those predisposed to angle-closure glaucoma.
• Systemic antimuscarinic effects can occur, particularly in children and older patients, so apply nasolacrimal occlusion and use with care.
• Blurred vision and light sensitivity persist while the effect lasts and impair vision and driving.

Monitoring

Assess for any rise in intraocular pressure in predisposed eyes and observe for systemic antimuscarinic effects in susceptible patients.

Counselling the patient

• Your vision will be blurred and you may be sensitive to light, so do not drive until it wears off.
• Wear sunglasses and press gently on the inner corner of the eye after the drops.
• Report any eye pain, severe redness or visual disturbance.

Evidence & guidelines

Homatropine is a long-established cycloplegic and mydriatic used in uveitis and ocular examination, with use guided by the SPC.