Lidocaine (Intranasal/Topical ENT)

How it works

Lidocaine is an amide local anaesthetic that reversibly blocks voltage-gated sodium channels in sensory nerve endings, preventing impulse conduction and thereby abolishing local pain sensation.

Prescribing in practice

• Systemic absorption across inflamed or highly vascular mucosa can be rapid, so respect the maximum recommended cumulative dose to avoid local-anaesthetic systemic toxicity (CNS excitation then depression, arrhythmias).
• Anaesthesia of the pharynx and larynx abolishes the gag reflex and impairs swallowing, increasing aspiration risk until sensation returns.
• Use with caution in patients with epilepsy, conduction abnormalities, hepatic impairment or porphyria, and have resuscitation facilities available for airway application.

Monitoring

Observe for early signs of systemic toxicity (peri-oral tingling, light-headedness, visual or auditory disturbance) and protect the airway until pharyngeal sensation and the gag reflex recover.

Counselling the patient

• Do not eat or drink until the numbness in your throat has fully worn off, to avoid choking.
• A bitter taste and temporary throat numbness are expected after spraying.
• Tell the clinician if you feel dizzy, develop tingling around the mouth or notice a ringing in your ears.

Evidence & guidelines

Topical lidocaine is a long-established standard for mucosal anaesthesia in ENT and airway procedures, with dosing and safety limits defined in the SPC and current prescribing references.