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Topical antimicrobial (sulfonamide + silver) Pregnancy: Section 4.6: no clinical data on exposed pregnancies are available, although animal studies have not shown any hazard. Since all sulphonamides increase the risk of kernicterus, it should not be used in pregnant females at term, and caution is required in nursing mothers. Systemically absorbed sulfadiazine can be excreted in breast milk at concentrations 15-35% of those found in serum.

Sulfadiazine silver

Brand names: Flamazine

Silver sulfadiazine is a topical antibacterial cream used to prevent and treat infection in burns and certain chronic wounds and leg ulcers.

Adult dose

Dose: Burns (prophylaxis and treatment of infection in burn wounds): clean the wound and apply 1% w/w silver sulfadiazine cream over all affected areas to a depth of 3-5 mm. Leg ulcers/pressure sores (short-term aid): fill the ulcer cavity with cream to a depth of at least 3-5 mm. Finger-tip injuries: after haemostasis, apply a 3-5 mm layer.
Route: Topical (applied to the wound)
Frequency: Burns: re-apply at least every 24 hours, or more frequently if the volume of exudate is large (and wherever the cream has been removed by patient activity). Leg ulcers/pressure sores: dressings normally changed daily; every 48 hours may be acceptable for less exudative wounds. Finger-tip injuries: dressings changed every 2-3 days.
Strength: FLAMAZINE Cream 1%, silver sulfadiazine 1.0% w/w (SPC section 2; contains cetyl alcohol 4% w/w and propylene glycol 7% w/w). Indications (section 4.1): prophylaxis and treatment of infection in burn wounds; aid to short-term treatment of infection in leg ulcers and pressure sores; aid to prophylaxis of infection in skin graft donor sites and extensive abrasions; conservative management of finger-tip injuries with pulp, nail loss and/or partial loss of the distal phalanx. Application technique (section 4.2): best with a sterile gloved hand and/or sterile spatula. Hand burns: apply to the burn and enclose the whole hand in a clear plastic bag or glove closed at the wrist; encourage movement; change the dressing when an excessive amount of exudate has accumulated. Leg ulcers: cream can macerate normal skin on prolonged contact, so prevent spread onto non-ulcerated areas; follow with an absorbent pad or gauze and pressure bandaging as appropriate; cleanse and debride before application; not recommended for very exudative leg or pressure ulcers. Finger tips: a conventional finger dressing, or the finger of a plastic or unsterile surgical glove fixed with waterproof adhesive tape. The SPC prints no maximum quantity or duration. Children: the SPC states the cream is contraindicated in children aged up to three months (its wording is 'aged to three months'; see section 4.3) and must not be used on premature or newborn infants during the first months of life; it gives no dose for older children, so no paediatric block is written. In large-area burns serum sulfadiazine levels may approach therapeutic levels, so effects of systemic drugs (oral hypoglycaemics, phenytoin) may be altered (section 4.5).

Dose adjustments

Renal

No dose adjustment given. Section 4.4: use with caution in the presence of significant hepatic or renal impairment.

Hepatic

No dose adjustment given. Section 4.4: use with caution in the presence of significant hepatic or renal impairment.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Not to be used at, or near term pregnancy, on premature infants or on newborn infants during the first months of life, because sulphonamides are known to cause kernicterus (section 4.3)
  • Contraindicated in children aged up to three months (section 4.2 wording: 'aged to three months', see section 4.3)
  • Patients known to be hypersensitive to sulphonamides, silver sulfadiazine, or other components such as cetyl alcohol or propylene glycol (section 4.3)
  • Not recommended for leg or pressure ulcers that are very exudative (section 4.2)

Side effects

  • Leukopenia (common) - reported in 3-5% of burns patients, often 2-3 days after starting, usually self-limiting (section 4.8)
  • Application site burning (common); pruritus (common); application site rash including eczema and contact dermatitis (common) (section 4.8)
  • Argyria (rare); with large-area wounds and/or prolonged application systemic silver absorption can cause clinical argyria (section 4.8)
  • Renal failure (very rare) (section 4.8)
  • Severe cutaneous adverse reactions - Stevens-Johnson syndrome and toxic epidermal necrolysis (very rare); highest risk within the first weeks; discontinue if suspected and never restart in that patient (sections 4.4, 4.8)
  • May delay separation of burn eschar and alter the appearance of burn wounds (section 4.4)
  • Prolonged contact may macerate normal skin (section 4.2)

Interactions

  • Enzymatic debriding agents - silver may inactivate them, so concomitant use may be inappropriate (section 4.5)
  • Oral hypoglycaemic agents and phenytoin - in large-area burns serum sulfadiazine may approach therapeutic levels and their effects may be potentiated; blood levels should be monitored (section 4.5)

Monitoring

  • Blood count in burns patients - monitor to ensure leukopenia returns to normal within a few days (section 4.8)
  • Skin reactions, particularly in the first weeks of treatment (signs of SJS/TEN) (section 4.4)
  • Blood levels of oral hypoglycaemics and phenytoin in large-area burns (section 4.5)

Clinical monograph

How it works

It releases silver ions active against the bacterial cell wall and membrane, together with a sulphonamide component, providing broad-spectrum antibacterial cover including against Pseudomonas.

Prescribing in practice

  • Contraindicated in sulphonamide hypersensitivity and avoided in pregnancy near term, in neonates and in infants because of the risk of kernicterus.
  • Application to large areas can cause systemic sulphonamide absorption and, rarely, leucopenia, with argyria reported after prolonged use.
  • May reduce the activity of concurrently applied enzymatic wound debriding agents.

Monitoring

With extensive or prolonged use, monitor full blood count and watch for signs of systemic absorption and hypersensitivity.

Counselling the patient

  • Temporary greyish skin discolouration at the site of application can occur.
  • Report rash, fever or other features of an allergic reaction.
  • The cream may stain clothing and bedding.

Evidence & guidelines

Silver sulfadiazine is a long-established topical antimicrobial for burns, supported by extensive clinical use rather than a single landmark trial.

Reference: UK burns 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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