Instillagel (Chlorhexidine Gluconate, Methyl Parahydroxybenzoate, Propyl Parahydroxybenzoate, Lidocaine Hydrochlo)

Instillagel is used in the urogenital tract to provide antisepsis, infection prophylaxis, and local analgesia during urethral procedures.

• Urethral antisepsis: reduces microbial load in the urethra before instrumentation, helping to prevent infection.
• Catheter‑associated urinary tract infection prophylaxis: applied during catheter insertion to lower the risk of developing a urinary tract infection.
• Local urethral analgesia: delivers lidocaine‑mediated numbness to ease discomfort during catheterisation or other urethral interventions.

• Chlorhexidine gluconate exerts its antiseptic effect by binding to bacterial cell membranes, disrupting their integrity and causing leakage of intracellular contents, which leads to cell death. Lidocaine hydrochloride acts as a local anaesthetic by reversibly blocking voltage‑gated sodium channels in nerve membranes, preventing depolarisation and thereby inhibiting pain signal transmission in the urethral mucosa. The combined formulation ensures simultaneous antimicrobial and analgesic action at the site of application.

Instillagel may cause local and systemic adverse reactions, which are categorised by frequency and severity.

Common Side Effects

• Burning or stinging sensation in the urethra during or shortly after application
• Transient urethral irritation or mild redness that resolves within minutes
• Mild hypersensitivity skin reaction such as localized rash or itching
• Altered taste sensation or mild oral discomfort after gel exposure

Serious or Rare Side Effects

• Anaphylactic reaction or severe allergic response requiring immediate medical attention
• Stevens‑Johnson syndrome or toxic epidermal necrolysis presenting with widespread skin blistering
• Severe urethral ulceration or necrosis that may necessitate discontinuation of therapy

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

• Allergy assessment: verify no known hypersensitivity to chlorhexidine, parabens or lidocaine.
• Indication confirmation: use only for urethral antisepsis, catheter‑related infection prophylaxis or local analgesia.
• Infection status: avoid in the presence of active urethral infection unless directed by a clinician.
• Systemic absorption monitoring: observe for signs of systemic toxicity, especially with prolonged or repeated use.
• Pregnancy and lactation: safety not established; use only if potential benefit outweighs risk.
• Store at room temperature: keep the gel in its original container, protect from light and moisture.

Instillagel can interact with other medicines or products; relevant interactions are grouped by clinical significance.

Major Interactions (Avoid)

• Concurrent use of other chlorhexidine‑containing products may increase local irritation risk.
• Co‑administration with systemic local‑anesthetic agents may potentiate lidocaine toxicity.
• Simultaneous application with ophthalmic or otic chlorhexidine preparations may lead to systemic absorption.

Moderate Interactions (Monitor Closely)

• Use with topical antibiotics may alter local bacterial flora and affect efficacy.
• Combination with antimicrobial‑coated catheters may produce additive antiseptic effects.
• Concomitant antihistamines may mask early signs of an allergic reaction.