Roxithromycin

Other macrohdes have been prepared which represent hybrids of stmctures within the 14-membered family, within the 16-membered family, or between the two families. These hybrids have been made by chemical, bioconversion, or genetic manipulations. The 9-0-[(2-methoxyethoxy)methyl]oxime of tylosin (Table 7) was synthesized, using the oxime found in roxithromycin (33) (369). 3-0-Cladinosyl derivatives of 16-membered macrohdes were synthesized in which the neutral sugar of erythromycin (Table 3) was attached to tylosin derivatives at thek 3-hydroxyl group, analogous to its position in erythromycin... 

Roxithromycin has similar in vitro activity to erythromycin but enters leucocytes and macrophages more rapidly with higher concentrations in the lysosomal component of the phagocytic cells. It is likely to become an important drug against Legionella pneumophila. Clarithromycin is also of potential value. 

Stuer et al. [46] evaluated the presence of the 25 most used pharmaceuticals in the primary health sector in Denmark (e.g., paracetamol, acetyl salicylic acid, diazepam, and ibuprofen). They compared PECs with experimental determinations and they conclude that measured concentrations were in general within a factor of 2-5 of PECs. Carballa et al. [45] also determined PECs for pharmaceuticals (17), musk fragrances (2) and hormones (2) in sewage sludge matrix. For that purpose they used three different approaches (1) extrapolation of the per capita use in Europe to the number of Spanish inhabitants for musk fragrances (2) annual prescription items multiplied by the average daily dose for pharmaceuticals and (3) excretion rates of different groups of population for hormones. They indicated that these PECs fitted with the measured values for half of them (carbamazepine, diazepam, ibuprofen, naproxen, diclofenac, sulfamethoxazole, roxithromycin, erythromycin, and 17a-ethiny I e strad iol). 

In order to determine more precisely the fate of pharmaceuticals during sludge treatment, different experiments have been conducted in controlled conditions. In continuous anaerobic reactors treating sludge spiked with pharmaceuticals, Carballa et al. [114] observed removals higher than 80% for naproxen, sulfamethoxazole, and roxithromycin, while 40% and 23% of ibuprofen and iopromide, respectively, were eliminated at both mesophilic (37°C) and thermophilic (55°C) temperatures. For diclofenac and diazepam, elimination of about 60% was observed in mesophilic conditions while in thermophilic conditions, 38% and 73% of these two compounds, respectively, were eliminated. In these experiments, the sludge retention time (15 or 30 days) did not seem to influence pharmaceutical removal... 

Radjenovic J, Godehardt M, Petrovic M, Hein A, Farre M, Jekel M, Barcelo D (2009) Evidencing generation of persistent ozonation products of antibiotics roxithromycin and trimethoprim. Environ Sci Technol 43 6808-6815... 

Roxithromycin, clarithromycin, azithromycin and dirithromycin are more recently developed macrolides with similar antimicrobial activity to erythromycin. However they are better absorbed, have longer elimination half-lives and lower incidence of gastrointestinal side-effects. Azithromycin and... 

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