Seven studies (n=654) were included in the review: five randomised and two non-randomised.
The included studies varied in terms of their methodological quality, with Jadad scores ranging from 1 to 5.
Vaginal candidosis.
One study found no significant differences between women supplied with either Solanum nigrescens or commercial nystatin suppositories, with 90% of the experimental and 94% of the comparative group being culture negative at the end of treatment.
Tinea infections.
One non-randomised study evaluated OBO in 70 patients with tinea corporis, cruris or pedis. The patients were assigned to treatment with 25% emulsion of OBO, 20% OBO in alcohol, 100% OBO or an imidazole derivative, for up to 4 weeks. One-quarter of patients using 100% OBO dropped out of the trial. Those patients completing the therapy in this group were reported to have been cured the most rapidly (33% in 1 week). The other two OBO preparations also produced more rapid cure rates than imidazole.
One randomised clinical trial (RCT) compared the efficacy of 10% w/w TTO, 1% tolnaftate and placebo creams applied twice daily for 4 weeks in 121 patients with tinea pedis. Significantly more tolnaftate-treated patients (85%) than TTO patients (30%) and placebo-treated patients (21%) showed conversion to negative culture by the end of treatment. Tolnaftate and TTO groups showed significantly greater improvement in symptomatology than the placebo group. Tolerability was reported to be excellent and only one adverse reaction was noted; the adverse effect occurred in the tolnaftate group.
A second RCT evaluated higher concentrations (25% and 50%) of TTO applied twice daily for 4 weeks, compared with placebo, in 158 patients with tinea pedis. Mycological cure was achieved in significantly more patients in both TTO groups than in those using placebo (55% and 64% versus 31%). Statistically significant improvements in clinical scores were also observed in the TTO groups (72% and 68% versus 39%). Tolerability was generally good. Three patients reported dermatitis: one with 25% TTO and two with 50% TTO.
Onchomycosis.
One double-blind RCT compared TTO with clotrimazole in 117 patients with subungual onychyomycosis. There were no statistically significant differences between TTO and clotrimazole in negative culture at the end of treatment (18% versus 11%) or full or partial resolution of symptoms (60% versus 61% post-treatment and 56% versus 55% at 3 months' follow-up).
One double-blind RCT evaluated 8 weeks' treatment with a combination of 2% butenafine hydrochloride and 5% TTO cream against a cream containing TTO only in 60 patients with toenail onychomycosis. The overall cure rates after 36 weeks were 80% (combination) and 0% (TTO), respectively.