Acanthamoeba keratitis
ICD-10 H19.2 · ICD-11 1F50/9A71

Acanthamoeba Keratitis: Next Step When Initial Dual Topical Therapy Fails to Control the Infection

Acanthamoeba keratitis requires intensive and sustained topical treatment. When the initial standard dual-agent regimen does not achieve the expected clinical response within the anticipated timeframe, a structured escalation protocol is indicated.

Previous treatment and failure condition: The patient received diagnostic epithelial debridement for culture and staining, followed by immediate topical dual therapy with chlorhexidine and propamidine. Clinical response with control of the keratitis — which can take up to two weeks to be appreciated — was not achieved. This protocol defines the next step after that failure.
Next-step approach: The escalation protocol centers on topical PHMB with substitution of the diamidine agent. The full structured regimen — including agent selection, specific dosing, and the complete tapering schedule — is available in the protocol below.
Instant Access to Structured Evidence-Based Regimens

References

In the event that the above therapy fails, Charles Leiter, Pharm.D. has said that the medications may be increased from a starting dose of 0.02% up to 0.06% for chlorhexidine or PHMB.

Hexamadine 0.1% or pentamidine isethionate 0.1% (Pentam 300) may be substituted for propamadine.

View source ↗