Combined Thiamidol and Low-fluence Q-switched Nd:YAG Laser for the Treatment of Facial Hyperpigmentation

Background: Thiamidol (isobutylamido thiazolyl resorcinol) is a novel human tyrosinase inhibitor recently shown to be effective in the treatment of hyperpigmentation. Low-fluence Q-switched Nd:YAG 1064-nm laser (LFQS) has proven to be effective for various hyperpigmentary conditions. However, there have been no studies to date on the efficacy and safety of combined Thiamidol and LFQS treatment. Objectives: To compare the efficacy and safety of combined Thiamidol-based serum and LFQS with LFQS monotherapy for facial hyperpigmentation. Materials and Methods: Patients with symmetrical facial hyperpigmentation were treated with five sessions of once weekly LFQS on the whole face. One side was randomly treated with a Thiamidol-based serum formulation and the other side received a placebo cream for 12 weeks. Patients were followed for 8 weeks after the last laser treatment. Relative lightness index (RL*I), Facial Hyperpigmentation Severity Score on the Malar Area (FHSSm), patient satisfaction, recurrence, and adverse events were recorded. Results: Twenty-four (N=24) patients completed the study. Both sides demonstrated significant reductions of mean RL*I and mean FHSSm from baseline (P < .01). At the 4th week, the Thiamidol-based serum treated side showed more improvement in mean RL*I than the placebo-treated side (62.5% vs 47.3% improvement, P < .05). The mean FHSSm on the Thiamidol-based serum treated was reduced at a significantly higher percentage than the placebo- treated side (54.4% vs 40.2% reduction, P < .05). Partial recurrence was observed on both sides. No serious side effects were noted. Conclusion: Combined Thiamidol-based serum and LFQS therapy was more superior than LFQS monotherapy in the treatment of facial hyperpigmentation. Thiamidol-based formulations may serve as adjuvant treatment for patients with hyperpigmentation with standard therapy.