42 patients with acne vulgaris, clinically resistant to prior therapy with tetracyclines, were evaluated after therapy with sulphamethoxazole-trimethoprim (400 + 80 mg) twice daily. Initially and after 6, 12 and 18 weeks of treatment in each patient the different acne lesions were counted and pus specimens from unhealed pustules were taken for bacteriological analysis. Complete remission or excellent results were obtained in 33 patients (79%) at the end of treatment despite a relative increase of Staphylococcus hominis and Propionibacterium granulosum. These species were more resistant in agar dilution test to the combination sulphamethoxazole-trimethoprim (20:1) than other isolated species.

The clinical efficacy and tolerance of a new retinoic acid derivative, Ro 11–1430, in the treatment of acne vulgaris have been compared with those of tretinoin in a double-blind trial with 60 patients during 8 weeks. The efficacy of both drugs was good. Tretinoin showed a tendency to give better effect but this was not statistically significant. However, tolerance of the new derivative was better. 48 of the patients were treated with Ro 11–1430 for another 3 months with good effect and tolerance. In a long-term study, 32 patients with previous irritation of tretinoin have been treated with Ro 11–1430 between 1.5 and 17 months with good tolerance.