The mycotic ulcer treatment trial: a randomized trial comparing natamycin vs voriconazole

OBJECTIVE

To compare topical natamycin vs voriconazole in the treatment of filamentous fungal keratitis.

METHODS

This phase 3, double-masked, multicenter trial was designed to randomize 368 patients to voriconazole (1%) or natamycin (5%), applied topically every hour while awake until reepithelialization, then 4 times daily for at least 3 weeks. Eligibility included smear-positive filamentous fungal ulcer and visual acuity of 20/40 to 20/400.

MAIN OUTCOME MEASURES

The primary outcome was best spectacle-corrected visual acuity at 3 months; secondary outcomes included corneal perforation and/or therapeutic penetrating keratoplasty.

RESULTS

A total of 940 patients were screened and 323 were enrolled. Causative organisms included Fusarium (128 patients [40%]), Aspergillus (54 patients [17%]), and other filamentous fungi (141 patients [43%]). Natamycintreated cases had significantly better 3-month best spectacle-corrected visual acuity than voriconazole-treated cases (regression coefficient=0.18 logMAR; 95% CI, 0.30 to 0.05; P=.006). Natamycin-treated cases were less likely to have perforation or require therapeutic penetrating keratoplasty (odds ratio=0.42; 95% CI, 0.22 to 0.80; P=.009). Fusarium cases fared better with natamycin than with voriconazole (regression coefficient=0.41 logMAR; 95% CI,0.61 to 0.20; P<.001; odds ratio for perforation=0.06; 95% CI, 0.01 to 0.28; P<.001), while non-Fusarium cases fared similarly (regression coefficient=0.02 logMAR; 95% CI, 0.17 to 0.13; P=.81; odds ratio for perforation=1.08; 95% CI, 0.48 to 2.43; P=.86).

CONCLUSIONS

Natamycin treatment was associated with significantly better clinical and microbiological outcomes than voriconazole treatment for smear-positive filamentous fungal keratitis, with much of the difference attributable to improved results in Fusarium cases.

APPLICATION TO CLINICAL PRACTICE

Voriconazole should not be used as monotherapy in filamentous keratitis.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00996736

Gellan Gum Based Sol-to-Gel Transforming System of Natamycin Transfersomes Improves Topical Ocular Delivery

Short precorneal residence time and poor transocular membrane permeability are the major challenges associated with topical ocular drug delivery. In the present research, the efficiency of the electrolyte-triggered sol-to-gel-forming system of natamycin (NT) transfersomes was investigated for enhanced and prolonged ophthalmic delivery. Transfersomes were optimized by varying the molar ratios of phospholipid, sorbitan monostearate (Span) and tocopheryl polyethylene glycol succinate (TPGS). NT transfersome formulations (FNs) prepared with a 1:1 molar ratio of phospholipid-to-Span and low levels of TPGS showed optimal morphometric properties, and were thus selected to fabricate the in situ gelling system. Gellan gum-based (0.3% w/v) FN-loaded formulations (FNGs) immediately formed an in situ gel in the simulated tear fluid, with considerable viscoelastic characteristics. In vitro cytotoxicity in corneal epithelial cells and corneal histology studies demonstrated the ocular safety and cytocompatibility of these optimized formulations. Transcorneal permeability of NT from these formulations was significantly higher than in the control suspension. Moreover, the ocular disposition studies of NT, from the FNs and FNGs, in New Zealand male albino rabbits demonstrated the superiority of the electrolyte-sensitive FNGs in terms of NT delivery to the ocular tissues.

Intravitreal effects of pimaricin in experimental fungal endophthalmitis

Evaluation of 25, 50, and 100 mug of pimaricin given intravitreally to albino rabbits with Aspergillus endophthalmitis revealed that 25 mug of pimaricin, while nontoxic to the retina, was ineffective in inhibiting the fungal process. A dose of 50 mug was significantly more effective in inhibiting fungal disease but also caused significant retinal damage with loss of retinal function and iridoplegia. Dosages above this level resulted in vitreous retraction and degeneration, iridoplegia, and retinal detachment. Twenty-five micrograms of pimaricin given in three dosages spaced three days apart may be effective in inhibiting fungal endophthalmitis.

[Fusarium keratitis and endophthalmitis treated by intravenous ambisome]

PURPOSE

This is a case study of Fusarium keratitis progressing to endophthatmitis that was successfully treated with a tiposomal formulation of amphotericin B (AmBisome] and local natamycin 5%.

METHODS

A 41-year-old man presented with a clinical picture of endophthalmitis following deep Fusarium solani keratitis. Treatment with natamycin 5% drops and intravenous amphotericin B 150 mg per day caused renal failure and did not alleviate the endophthalmitis. Therefore, intravenous amphotericin B was replaced with intravenous AmBisome, 300 mg per day, to a cumulative dosage of 5.4 g.

RESULTS

Both the endophthalmitis and keratitis were alleviated within several weeks after starting AmBisome treatment. No systemic toxicity was noted. The final ophthalmoLogic examination showed a paracentral corneal scar, and a satisfactory best corrected visual acuity of 20/40.

CONCLUSIONS

Due to their relatively low systemic toxicity, liposomal formulations of amphotericin B can be administered in higher doses than traditional unencapsulated ntravenous amphotericin B achieving higher concentrations in the target organ.

Efficacy and safety of vaginal suppositories containing combination of Natamycin and Lactulose in treatment of vulvovaginal candidiasis: international, randomized, controlled, superiority clinical trial (combination of Natamycin and Lactulose for treatment of vulvovaginal candidiasis)

BACKGROUND

The study aimed to assess the efficacy and safety of Natamycin + Lactulose vaginal suppositories (100 mg natamycin and 300 mg lactulose) (AVVA RUS JSC, Russia) in adult females with vulvovaginal candidiasis.

METHODS AND RESULTS

An international, randomized, controlled, assessor-blinded clinical trial enrolled 218 females randomly distributed into three groups: Natamycin + Lactulose (92 patients), Lactulose (36 patients), and Pimafucin® (90 patients). The study drug and comparator drugs had an identical dosing regimen (one suppository intravaginally once a day at bedtime for six days). The study involved four visits to the study site with examination at Visits 2 and 3. The fixed-dose combination of Natamycin + Lactulose was superior to both comparator drugs in terms of the primary efficacy endpoint defined as the percentage of patients achieving a clinical recovery: the absence of symptoms of vulvovaginal candidiasis. At Visit 2, clinical recovery was reported in 81.6% of females in the Natamycin + Lactulose group compared to 42.9% and 62.3% of patients in the Lactulose and Pimafucin groups, respectively. The difference in proportions was 38.8% and 18.4%. In the Natamycin + Lactulose group, microscopic recovery was observed in 75.9% of patients at Visit 2 and in 90.8% of patients at Visit 3. In the Lactulose group, 45.7% and 74.3% subjects responded positively at Visits 2 and 3. In Pimafucin group, microscopic recovery was reported in 71.3% and 88.5% of patients at Visits 2 and 3, respectively, while no differences were observed between the Natamycin + Lactulose and Pimafucin groups at both visits. At Visit 3, the number of vaginal lactobacilli was significantly higher in the Natamycin + Lactulose group. In females with the low baseline content of vaginal lactobacilli, the combination drug under investigation increased the vaginal lactobacilli content to the reference values in 15.4% and 20.9% of patients at Visit 2 and Visit 3, respectively.

CONCLUSIONS

The fixed-dose combination Natamycin + Lactulose 100 mg + 300 mg vaginal suppositories (AVVA RUS JSC, Russia) demonstrated superior efficacy compared to 1) Pimafucin 100 mg and 2) Lactulose 300 mg vaginal suppositories in adult females with vulvovaginal candidiasis.

TRIAL REGISTRATION

NCT06411314, retrospectively registered on May, the 13th, 2024.