Tolerability and efficacy of N‐chlorotaurine in comparison with chloramine T for the treatment of chronic leg ulcers with a purulent coating: a randomized phase II study

Summary Background  The well-known active chlorine compound chloramine T (CAT) with broad-spectrum antimicrobial activity is in common therapeutic use for leg ulcers with purulent coatings; however, this treatment is painful. The tolerability of the less aggressive N-chlorotaurine (NCT), an endogenous compound also produced in vivo by stimulated human granulocytes, could be superior. Objectives  To assess the tolerability and efficacy of NCT in the cleaning of purulent coatings in chronic leg ulcers in comparison with CAT. Methods  In a double-blind, randomized phase IIb clinical study 40 patients were treated for a median of 7 days (range 3–14) with a 1% aqueous solution of either NCT (20 subjects) or CAT (20 subjects) by twice-daily application of dressings soaked in the test solutions. Criteria for evaluation of tolerability were intensity and duration of pain caused by the ulcer therapy and scores of tissue toxicity (necrosis, granulation tissue and re-epithelialization). Therapeutic efficacy was graded as scores of intensity of purulent coating of the ulcers. Results  The concentration tolerated in vitro by human epidermoid carcinoma cells was at least 10-fold higher for NCT (0·01%) compared with CAT (0·0001–0·001%). There was significantly less pain caused by NCT compared with CAT (P < 0·05) on days 1 and 4 and a trend for a shorter duration of pain (P = 0·093). The scores of intensity of coating improved without difference in both treatment groups, whereas granulation and re-epithelialization appeared earlier in the NCT group (P < 0·05). Non-quantitative microbiological cultures from ulcer smears revealed persistence of colonization by bacterial species in approximately half of both treatment groups. Conclusions  Both active chlorine compounds were helpful in reducing purulent coatings. Because of its lower toxicity and better tolerability, NCT is of advantage in the treatment of leg ulcers.