Corynebacterium acnes strains cross-resistant to clindamycin and erythromycin were observed following long-term selection or mutagenic treatment in the laboratory. Similar strains were found among clinical isolates from patients using clindamycin or erythromycin topically in the treatment of acne vulgaris. Clindamycin resistance was never observed in the absence of resistance to macrolides or other lincosaminides. It is suggested that this resistance may result from an alteration of the 50S ribosomal subunit.

No abstract

Twenty-two patients were treated with desoximetasone emollient cream 0.25% twice daily without occlusion for 6 months. Patients applied the medication to approximately one-third of their body over psoriatic lesions. Corticosteroid plasma cortisol values decreased to below normal limits in nine patients before the 6-month study was terminated. In four of these the plasma cortisol spontaneously returned to normal despite therapy; in four other patients, however, the plasma cortisol was still suppressed at the end of 5 months of continual therapy but returned to normal within 7 days of discontinuation of the medication. In one patient, lost to further follow-up at 5 1/2 months of therapy, the trend at the fourth month was an increase in plasma cortisol to within one unit of normal range. Betamethasone 17-valerate 0.1% cream applied twice daily did not suppress plasma cortisol in twenty-three patients similarly tested. The clinical response to desoximetasone emollient cream was significantly better than to betamethasone valerate cream. This study closely approximates the way in which many patients with steroid-responsive dermatoses use potent topical steroids, namely over a long time period and without occlusion.

Trade name glucocorticoid formulations triamcinolone acetonide, fluocinolone acetonide, and betamethasone valerate were compared with their generic equivalents because of increasing substitution of generic formulations for trade name formulations. The vasoconstrictor assay was the method used for these comparisons. Large differences were found between generic and trade name formulations containing the same steroid in the same concentration in both cream and ointment vehicles. If generic substitutions are to be used for trade name formulations, the physician must be aware that significant differences in therapeutic effectiveness may be expected.