tetracycline and nadifloxacin

The etiology of acne vulgaris is complicated and characterized by two aspects, non-inflammatory and inflammatory mechanisms. The non-inflammatory aspect is represented by follicular occlusion by sebaceous materials and resultant formation of comedo. On the other hand, acne features the continuing occurrence of inflammation, which yields reddish popular or nodular lesions. Therefore, acne is not a simple infection with Propionibacterium acnes, but subsequent inflammatory changes are the nature of acne. New quinolones, macrolides and tetracyclines are used for the treatment of acne as topical or systemic drugs. Recent accumulated evidence has suggested that these drugs exert their therapeutic effects by not only bacteriocidal actions but also anti-inflammatory or anti-immunological actions. These effects include antioxidative action toward neutrophils, inhibition of cytokine/chemokine production and adhesion molecule expression by keratinocytes, and suppression of the antigen-presenting ability of Langerhans cells. Drugs possessing these anti-inflammatory capacities are clinically beneficial for the treatment of inflammatory acne.

Topics: Acne Vulgaris; Administration, Topical; Anti-Bacterial Agents; Anti-Inflammatory Agents; Clindamycin; Fluoroquinolones; Humans; Immunologic Factors; Macrolides; Propionibacterium acnes; Quinolizines; Tetracycline

Impetigo contagiosa staphylogenes is commonly treated by administering a combination of nadifloxacin and tetracycline ointments. However, it is not clear whether nadifloxacin and tetracycline are stable after mixing. The purpose of this study was to evaluate the stability of these agents in combination. We also evaluated changes in antibacterial activity after mixing. Mixing the two ointments caused tetracycline to change from yellow to brown in the admixture. Furthermore, the tetracycline content in the ointment decreased in a time-dependent manner, to about 40% at 288 h after mixing. In addition, the nadifloxacin content in the ointment did not change 288 h after mixing. In an alkaline environment (pH 9.0 and 11.0), the tetracycline content decreased and the color of tetracycline changed to brown. These results suggest that sodium hydroxide, which is an additive in nadifloxacin ointment, influences the content of tetracycline. We evaluated the chemical sensitivity of Staphylococcus aureus using disk tests. Nadifloxacin and tetracycline ointment showed the largest radius of inhibition circle, followed by the admixture 0 h after mixing and the admixture 72 h after mixing. These results suggest that the antibacterial activity is inhibited by the admixture. We propose that pharmacists should avoid mixing nadifloxacin with tetracycline ointment in the treatment of impetigo contagiosa staphylogenes and should take care to avoid interactions caused by additives in the ointments.

Topics: Drug Combinations; Drug Interactions; Drug Resistance, Bacterial; Drug Stability; Fluoroquinolones; Hydrogen-Ion Concentration; Ointments; Quinolizines; Staphylococcus aureus; Tetracycline; Time Factors