Instillagel (Lidocaine Hydrochloride)

• Instillagel, a lidocaine‑based local anesthetic, is used for urogenital procedures that require urethral anesthesia.
• Urethral anesthesia for diagnostic procedures: provides pain relief during cystoscopy or uroflowmetry.
• Therapeutic urethral procedures: facilitates comfortable performance of urethral dilatation or surgery.
• Catheterization discomfort relief: reduces pain and spasm when inserting urinary catheters.
• Post‑procedure urethral care: helps manage pain after urological interventions.

• Lidocaine hydrochloride reversibly blocks voltage‑gated sodium channels on neuronal membranes, preventing depolarisation and the transmission of pain signals. By stabilising the neuronal membrane, it produces a rapid, temporary loss of sensation in the area where the gel is applied, allowing painless urethral manipulation.

Instillagel may cause local and systemic adverse reactions.

Common Side Effects

• Burning or stinging sensation at the application site.
• Mild irritation or redness of the urethral mucosa.
• Transient numbness that resolves after the gel is cleared.

Serious or Rare Side Effects

• Allergic reactions such as rash, urticaria, or angioedema.
• Systemic lidocaine toxicity presenting as dizziness, seizures, or cardiac arrhythmia.
• Severe local tissue necrosis if applied excessively or left in situ for prolonged periods.

• Before using Instillagel, consider the following safety measures.
• Allergy assessment: confirm no known hypersensitivity to lidocaine or amide‑type anesthetics.
• Pregnancy and lactation: use only if the potential benefit justifies the potential risk; data are limited.
• Age considerations: exercise caution in paediatric or geriatric patients due to altered absorption.
• Concurrent local anesthetics: avoid exceeding the total recommended lidocaine dose.
• Urethral pathology: do not use in the presence of severe infection, ulceration, or trauma.
• Store at room temperature below 25°C: keep in the original container, protect from moisture and direct sunlight.

Instillagel can interact with other medicines; monitor the following.

Major Interactions (Avoid)

• Class I antiarrhythmic agents (e.g., quinidine, procainamide): may increase systemic lidocaine levels.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): can raise lidocaine exposure.
• Concurrent use of other local anesthetics: risk of cumulative toxicity.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may enhance cardiac depressant effects of lidocaine.
• Diuretics such as furosemide: may alter lidocaine clearance.
• Anticonvulsants: may affect seizure threshold when lidocaine systemic absorption occurs.