Successful Treatment of Acanthamoeba Keratitis by Hexamidine

Abstract

Acanthamoeba keratitis remains very difficult to treat because of the lack of antiamoebic agents completely effective against cysts. Currently, the recommended treatment includes the use of topical neomycin sulfate, various imidazoles, and propamidine isethionate (Brolene) 0.1% eye drops, a compound of the diamidine family. In the present article, we describe the successful management of two patients with an Acanthamoeba keratitis, treated with hexamidine diisethionate (Desomedine) 0.1% eye drops, another diamidine derivative, which was found amoebicidal in vitro on the isolated Acanthamoeba strains. This is to our knowledge the first report on the amoebicidal effectiveness of hexamidine, simultaneously in vitro and in vivo.

Acanthamoeba keratitis update—incidence, molecular epidemiology and new drugs for treatment

“…The results given in this paper for the MTAC and MCC tests, using the commercial preparation of hexamidine (Desmodine), disagree with those of Perrine et al 61 and Brasseur et al 62 and find it to be less effective than propamidine. These and other results are given in Table 2.…”

“…62 In the UK, many optometrists and pharmacists issue propamidine (Brolene) as an over-the-counter eye drop medicine for sore, red eyes not needing a prescription, with over 3 million doses issued per year. A few of these red eyes in CLW are likely due to early Acanthamoeba infection.…”

Activities of Therapeutic Agents and Myristamidopropyl Dimethylamine against Acanthamoeba Isolates

“…Similar success has also been recorded with topical chlorhexidine digluconate (0.02%), which has also been shown to have good cysticidal activity (15). The propamidine homologue hexamidine di-isethionate has been shown to have greater cysticidal activity than propamidine and has been used alone and in combination therapy with PHMB or chlorhexidine to treat acanthamoeba keratitis (2,14).…”

“…The greater cysticidal activity of hexamidine di-isethionate than of propamidine isethionate has been noted previously, and the agent has been used in the successful treatment of the infection (2,14). However, all strains were sensitive to PHMB, chlorhexidine digluconate, and MAPD.…”

Acanthamoebaspp. as Agents of Disease in Humans

“…However, propamidine is not recommended for all cases since some patients with AK have developed corneal abnormalities following prolonged treatment (206,323). A successful outcome has been reported for patients with superficial AK treated with 0.1% hexamidine (51). A series of 12 patients with cultureproven AK were monitored during and after therapy with topical chlorhexidine and propamidine.…”