Topical NSAID / local analgesic 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

Benzydamine hydrochloride is a locally acting non-steroidal anti-inflammatory agent used as an oromucosal spray or mouthwash to relieve pain and inflammation 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

Applied topically it exerts local anti-inflammatory and analgesic effects on the inflamed oral and pharyngeal mucosa, with an additional local anaesthetic-like action.

Prescribing in practice

It is for local use in the mouth and throat only; transient stinging or numbness of the mouth can occur, and the mouthwash may be diluted with water if it causes stinging.
It is useful for painful mucosal conditions including radiotherapy- or chemotherapy-related mucositis and post-procedural sore throat.
Occasional hypersensitivity reactions and, rarely, oral numbness or mucosal irritation may occur.

Monitoring

No routine monitoring is required; review symptom relief and local tolerability at follow-up.

Counselling the patient

Use it to rinse or spray the affected area and do not swallow large amounts.
If the mouthwash stings, you can dilute it with the same amount of water.
Stop and seek advice if you develop a rash, swelling or worsening irritation.

Evidence & guidelines

Benzydamine is an established topical option for oropharyngeal pain and is supported by oncology supportive-care guidance for the symptomatic management of oral mucositis.

Reference: NICE NG84; ESMO mucositis guidance; 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).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways