Antiseptic / disinfectant (bisbiguanide) Pregnancy: Considered safe topically — minimal systemic absorption.

Chlorhexidine

Brand names: Corsodyl (mouthwash 0.2%), Hibiscrub (skin scrub 4%), Hibitane, ChloraPrep (skin prep 2% + alcohol 70%)

Adult dose

Dose: Mouthwash 0.2% (Corsodyl): 10 ml rinse/gargle for 1 minute BD for 4–14 days (gingivitis, post-extraction). Skin antisepsis pre-op: ChloraPrep 2% in 70% alcohol — apply with friction, allow to dry fully (≥3 min) before incision/cannulation. Surgical scrub: Hibiscrub 4% — wet hands, apply 5 ml, scrub 3 min, rinse, repeat. CVC dressing: 2% chlorhexidine impregnated dressing changed every 7 days (or sooner if soiled).

Route: Oromucosal / Topical

Frequency: BD–QDS (mouthwash) or as required (skin)

Allow alcohol-based skin prep to FULLY DRY (≥3 minutes) before diathermy or surgical drape — fire risk. Do not pool in body cavities.

Paediatric dose

Route: Topical / Oromucosal

Frequency: Variable

Mouthwash >12 yrs (alcohol content; brush-on gel <12 yrs). Skin antisepsis: avoid alcohol-based formulations on neonates and preterm <2 weeks (chemical burns). Use aqueous chlorhexidine 0.5–2% for neonatal cord care under specialist guidance.

Clinical pearls

Use 2% chlorhexidine + 70% alcohol (ChloraPrep) for ALL skin antisepsis prior to CVC, arterial line, surgery — superior to povidone-iodine (CHG-CLEAN-CVC trial; CHG vs PVI meta-analyses).
Anaphylaxis risk has risen in UK — always check for previous reaction; chlorhexidine-coated CVCs and urinary catheters are common occult exposures. Patient may not know they have had it. The UK NHS now requires chlorhexidine-allergy alerts on records.
Mouthwash: tooth staining is the leading cause of patient discontinuation; counsel and limit to ≤2 weeks unless specialist indication.
Brush teeth FIRST, wait 30 min, THEN rinse — toothpaste anionic detergent inactivates chlorhexidine.
Allow alcohol prep to fully dry (≥3 min) before draping or diathermy — well-documented operating theatre fire cause.
Avoid alcohol-based formulations on preterm/neonatal skin — chemical burns.

Contraindications

Hypersensitivity to chlorhexidine (anaphylaxis well-described — increasingly common; check history)
Application to brain, meninges, middle ear (ototoxicity, neurotoxicity)
Open wounds with exposed bone/cartilage (chondrotoxicity)
Eyes (severe corneal damage)

Side effects

Tooth staining (brown — common with mouthwash; reversible with dental cleaning)
Taste disturbance (mouthwash)
Reversible parotid swelling (rare with mouthwash)
Skin irritation, contact dermatitis
Anaphylaxis (rare but severe — increasingly recognised as cause of perioperative anaphylaxis in UK, esp. with CVC insertion or urinary catheter lubricant)
Mucosal burns / chemical injury if pooled or used on broken skin (especially in neonates)
Ototoxicity if introduced into middle ear

Interactions

Anionic agents (toothpaste with SLS): inactivate chlorhexidine — separate mouthwash from brushing by 30 minutes
Soaps, detergents: inactivate — rinse skin thoroughly before applying

Monitoring

Allergy alerts in records if any reaction
Tooth/dental review if mouthwash used >2 weeks

Reference: BNFc; BNF 90; SmPC Corsodyl / Hibiscrub / ChloraPrep; epic3 Guidelines (2014); NICE CG139 (Healthcare-associated infections); MHRA Drug Safety Update Oct 2012 (chlorhexidine anaphylaxis). Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways