Tropicamide with phenylephrine and lidocaine

How it works

Tropicamide (antimuscarinic) relaxes the iris sphincter and phenylephrine (alpha-agonist) stimulates the iris dilator to produce mydriasis, while lidocaine blocks sodium channels in sensory nerves to provide local anaesthesia of the anterior segment.

Prescribing in practice

• It is for intraocular surgical use by the operating surgeon, so it must be handled under sterile technique and the formulation and route confirmed, as it is not an ordinary topical drop and phenylephrine can still produce systemic cardiovascular effects.
• Use with caution in patients with cardiovascular disease and where the anterior chamber is shallow, given the mydriatic and sympathomimetic components.
• It supports intraoperative dilation and anaesthesia and is not a substitute for the standard pre-operative regimen where that is required.

Monitoring

Intraoperative monitoring covers pupil size and maintenance of dilation and, in susceptible patients, systemic cardiovascular response to phenylephrine.

Counselling the patient

• This is given by the surgeon during your cataract operation to keep the pupil open and numb the eye.
• Your vision will be blurred and the eye light-sensitive afterwards, so arrange not to drive home.
• Report any chest symptoms or palpitations during the procedure to the team.

Evidence & guidelines

Intracameral combinations of mydriatics with lidocaine are an established approach to intraoperative pupil dilation and anaesthesia in cataract surgery, with phenylephrine cardiovascular cautions noted in the SPC.