Instillagel (Chlorhexidine Gluconate, Lidocaine Hydrochloride)

Instillagel, a combination antiseptic and local anesthetic gel, is used in the urogenital tract to prepare and comfort patients during procedures.

• Urethral antisepsis: reduces bacterial contamination before diagnostic or therapeutic urethral interventions.
• Local anesthesia for urethral procedures: provides temporary numbness to facilitate catheter insertion or endoscopic examination.
• Pre‑catheterisation preparation: cleanses the urethral meatus and minimizes discomfort during catheter placement.

• Chlorhexidine gluconate exerts broad‑spectrum antimicrobial activity by binding to bacterial cell walls and disrupting membrane integrity, leading to leakage of intracellular contents and cell death. Lidocaine hydrochloride acts as a local anesthetic by reversibly blocking voltage‑gated sodium channels in peripheral nerve membranes, preventing depolarisation and transmission of pain signals. The combined formulation therefore simultaneously reduces microbial load and provides temporary sensory blockade at the site of urethral application.

Instillagel may cause local reactions at the application site and, in rare cases, systemic hypersensitivity.

Common Side Effects

• Burning or stinging sensation at the urethral site.
• Transient redness or erythema.
• Local itching or mild irritation.
• Temporary taste disturbance.

Serious or Rare Side Effects

• Allergic contact dermatitis.
• Anaphylactic reaction.
• Severe urethral inflammation or ulceration.

Before using Instillagel, consider the following precautions to ensure safe and effective application.

• Allergy assessment: avoid use in patients with known hypersensitivity to chlorhexidine or lidocaine.
• Infection caution: do not apply to severely infected urethral tissue unless directed by a clinician.
• Volume control: limit the administered amount to the prescribed volume to reduce systemic absorption.
• Systemic toxicity monitoring: observe for signs of lidocaine toxicity such as dizziness, tinnitus, or seizures.
• Cardiac considerations: use with caution in patients with known conduction abnormalities or receiving anti‑arrhythmic therapy.
• Store at ambient temperature below 25°C: keep in the original container, protect from moisture and direct light.

Instillagel can interact with other medications; awareness of these interactions helps minimise risk.

Major Interactions (Avoid)

• Concurrent use of other topical anesthetics: may increase total lidocaine exposure.
• Systemic lidocaine‑containing drugs (e.g., anti‑arrhythmics): risk of additive plasma lidocaine levels.
• Simultaneous application of additional chlorhexidine products: may cause excessive local irritation.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may potentiate local anesthetic effects, requiring observation.
• Anticoagulants: monitor for increased bleeding if urethral trauma occurs during the procedure.