Two streptogramins are clinically important in human medicine in the treatment of last resort of vancomycin resistant enterococci, namely pristinamycin and the combination dalfopristin/quinupristin. ... The risk of reducing the effectiveness of human medicinal products such as erythromycin in particular and possibly lincomycin, clindamycin, pristinamycin and the new combination dalfopristin/quinupristin, which is due to be authorised as a human medicinal product shortly, as a result of selection of cross-resistance caused by tylosin phosphate and spiramycin, should be avoided. ... SCAN notes in its opinion that the virginiamycin-resistant enterococci and staphylococci isolated from poultry and pigs all had cross-resistance to pristinamycin used in human medicine or the combination dalfopristin/quinupristin, which is due to be authorised as a human medicinal product shortly.
Synercid® (quinupristin and dalfopristin powder for injection) I.V., a streptogramin antibacterial agent for intravenous administration, is a sterile lyophilized formulation of two semisynthetic pristinamycin derivatives, quinupristin (derived from pristinamycin I) and dalfopristin (derived from pristinamycin IIA) in the ratio of 30:70 (w/w).
