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Topical antiseptic / antifungal

Cetrimide with undecenoic acid

Cetrimide with undecenoic acid is a topical preparation combining a quaternary ammonium antiseptic with an antifungal fatty acid, used for minor superficial fungal skin infections such as athlete's foot.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Undecenoic acid provides fungistatic activity against dermatophytes while cetrimide acts as a cationic surfactant antiseptic, together reducing fungal and bacterial colonisation of the skin.

Prescribing in practice

  • It is intended for minor superficial infections; more extensive or resistant dermatophyte infection warrants a more effective specific antifungal.
  • Cetrimide can occasionally cause skin sensitisation or irritation.
  • Avoid contact with the eyes and apply to clean, dry skin, particularly between the toes.

Monitoring

Review clinically to confirm resolution and to detect any local irritation or sensitisation.

Counselling the patient

  • Keep the affected area, especially between the toes, clean and thoroughly dry.
  • Continue treatment for the recommended duration even once the skin improves.
  • Stop and seek advice if the skin becomes irritated or the infection spreads.

Evidence & guidelines

Undecenoate-containing topical preparations are established options for minor superficial fungal skin infections.

Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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