Instillagel (Chlorhexidine Gluconate, Lidocaine Hydrochloride)

Instillagel, containing chlorhexidine gluconate and lidocaine hydrochloride, is used in the urological field to manage infection risk and procedural discomfort.

• Urethral catheterisation: Reduces bacterial colonisation and infection risk during catheter placement.
• Cystoscopic procedures: Provides local analgesia and antisepsis to improve patient comfort.
• Urethral surgery: Helps prevent postoperative infection and eases intra‑operative pain.

• Chlorhexidine gluconate binds to bacterial cell membranes, causing loss of integrity and cell death, thereby providing broad‑spectrum antimicrobial activity. Lidocaine hydrochloride penetrates nerve membranes and blocks voltage‑gated sodium channels, preventing depolarisation and producing a reversible local anaesthetic effect at the urethral mucosa.

Instillagel may cause local or systemic reactions, most of which are mild and transient.

Common Side Effects

• Urethral irritation: mild burning or discomfort during application.
• Local erythema: redness at the site of administration.
• Transient dysuria: temporary painful urination.
• Mild allergic reaction: localized itching or rash.
• Taste disturbance: brief metallic taste if gel contacts oral cavity.
• Headache: occasional mild headache after use.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Severe urethral ulceration: extensive mucosal damage.
• Systemic lidocaine toxicity: signs include dizziness, tinnitus, or cardiac arrhythmia.
• Chlorhexidine‑induced anaphylaxis: rare but potentially life‑threatening.
• Persistent urinary retention: prolonged difficulty voiding.
• Neurotoxicity: rare central nervous system effects with excessive systemic absorption.

When using Instillagel, consider the following safety measures.

• Allergy assessment: Confirm no known hypersensitivity to chlorhexidine or lidocaine.
• Mucosal integrity: Avoid in patients with severe urethral trauma or ulceration.
• Concurrent anaesthetics: Use caution if other local anaesthetics are administered.
• Systemic exposure: Monitor for signs of lidocaine toxicity in prolonged or repeated use.
• Pediatric use: Not recommended unless specifically prescribed by a qualified clinician.
• Store at ambient temperature: Keep in original packaging, protect from moisture and direct sunlight.

Instillagel may interact with other medications; awareness helps minimise risk.

Major Interactions (Avoid)

• Systemic lidocaine products: Increased risk of lidocaine toxicity.
• Other chlorhexidine‑containing preparations: Cumulative mucosal irritation.
• High‑dose local anaesthetics: Potential additive neuro‑cardiac effects.

Moderate Interactions (Monitor Closely)

• Anticoagulants: Monitor for bleeding if urethral trauma occurs.
• Immunosuppressants: Observe for delayed wound healing.
• Renal impairment: Adjust monitoring as lidocaine clearance may be reduced.