Natamycin 5% Eye Drops

How it works

It binds to ergosterol in the fungal cell membrane, disrupting membrane integrity and causing leakage of cellular contents, which produces a fungicidal effect against susceptible fungi.

Prescribing in practice

• Fungal keratitis is a sight-threatening infection that requires specialist ophthalmology management and close follow-up, as treatment is often prolonged.
• It is a suspension that should be shaken before use, and poor adherence of the drug to the corneal surface can limit penetration into deeper infection.
• Lack of clinical improvement may indicate a resistant organism or a non-fungal cause and warrants reassessment.

Monitoring

Treatment is monitored by frequent slit-lamp examination to track healing of the corneal lesion and is continued until resolution is confirmed.

Counselling the patient

• Shake the bottle well before each use and instil exactly as directed, as treatment may be needed for a prolonged period.
• Attend all follow-up appointments so the cornea can be examined closely.
• Report any worsening pain, redness or visual loss without delay.

Evidence & guidelines

Natamycin is an established first-line topical antifungal for filamentous fungal keratitis, supported by comparative trial evidence and the SPC.