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Topical NSAID (oropharyngeal) Pregnancy: No clinical data in pregnancy; should not be used in pregnancy unless considered essential by the physician. From week 20 onward use may cause oligohydramnios from foetal renal dysfunction, and ductus arteriosus constriction has been reported after second-trimester treatment - keep dose as low and duration as short as possible, and consider antenatal monitoring for oligohydramnios and ductus arteriosus constriction after several days' exposure from gestational week 20. CONTRAINDICATED during the third trimester (risk of premature constriction/closure of the ductus arteriosus, pulmonary hypertension, renal dysfunction, prolonged bleeding time and delayed/prolonged labour). Should not be used during lactation unless considered essential by the physician.

Benzydamine hydrochloride

Brand names: Difflam, Difflam-C (with chlorhexidine)

Benzydamine hydrochloride is a topically acting analgesic and anti-inflammatory agent used as a mouthwash or spray for painful inflammatory conditions of the mouth and throat.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 4 to 8 puffs of benzydamine hydrochloride 0.15% w/v oromucosal spray
Route: Oromucosal spray (SPC states 'For oral use')
Frequency: Every 1.5 to 3 hours
Dose applies to adults, adolescents and the elderly. Elderly: because of the small amount of drug applied, elderly patients can receive the same dose as adults. Paediatric dosing stated in the SPC (not a mg/kg dose, so not captured as a structured paediatric dose) - children 6 to 12 years: 4 puffs every 1.5 to 3 hours; children under 6 years: one puff to be administered per 4 kg of body weight, up to a maximum of 4 puffs, every 1.5 to 3 hours. Clinician to verify all paediatric use against a children's formulary. No maximum adult daily dose or maximum duration is stated in SPC section 4.2. Avoid contact with the eyes; if the condition is aggravated or not improved, use should cease. Source product: Benzydamine Hydrochloride 0.15% w/v Oromucosal Spray (UK SPC).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to benzydamine hydrochloride or to any of the excipients
  • Third trimester of pregnancy (SPC section 4.6 states benzydamine spray is contraindicated during the third trimester)

Side effects

  • Oral numbness and a stinging feeling in the mouth (uncommon; described as the most common side effects - stinging has been reported to disappear on continuing treatment, but if it persists treatment should be discontinued)
  • Laryngospasm or bronchospasm (very rare)
  • Pruritus, urticaria, photosensitivity reaction and rash (very rare)
  • Angioedema (frequency not known)
  • Anaphylactic reactions and hypersensitivity reactions (frequency not known)

Interactions

  • None known (SPC section 4.5)

Clinical monograph

How it works

It is a non-steroidal agent with local analgesic and anti-inflammatory effects, and also exerts a local anaesthetic and mild antiseptic action on inflamed mucosa.

Prescribing in practice

  • It is for local oropharyngeal use only and patients should be advised that stinging or numbness of the mouth may occur on application.
  • The mouthwash may be diluted with water if it causes stinging, particularly in ulcerated mucosa.
  • It is useful for mucositis-related pain but provides symptomatic relief rather than treating the underlying cause.

Monitoring

No specific monitoring is required; assess symptomatic relief and local tolerability.

Counselling the patient

  • Use the mouthwash or spray for symptom relief and do not swallow large amounts.
  • Dilute the mouthwash with water if it stings.
  • Seek advice if mouth or throat symptoms persist.

Evidence & guidelines

Topical benzydamine is a recognised option for symptomatic relief of oral mucositis and oropharyngeal inflammation.

Reference: SmPC Difflam; NICE CKS Mouth Ulcers; NCI/MASCC Mucositis Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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