Rokitamycin is a semisynthetic macrolide
antibiotic, closely related to miokamycin(2) both in structure and antimicrobial spectrum.
White to slightly yellow powder, odorless, bitter taste. Very soluble in methanol, ethanol, ether, acetone or ethyl acetate, insoluble in water or hexane. Melting point 116℃. [α] D25-50° (C=1, chloroform); [α] D20 -71° (C=1.0, chloroform) has also been reported.UV Maximum Absorbance (ethanol): 232 nm (ε28000).
ChEBI: Rokitamycin is an organic molecular entity.
Pharmaceutical Applications
3″-Propionyl leucomycin A5. A semisynthetic macrolide. Unstable in acid media.
The antibacterial spectrum is identical to that of erythromycin, but it is less active against Gram-positive cocci. It is poorly active against H. influenzae (MIC50 8 mg/L) and Mor. catarrhalis (MIC50 4 mg/L). It displays good activity against Campylobacter spp. (MIC50 0.1 mg/L), L. pneumophila (MIC50 0.1 mg/L) and M. pneumoniae (MIC50 0.003 mg/L). It is active against anaerobes, including some Bacteroides spp. (MIC50 <0.05 mg/L).
After a single oral dose of 600 mg, the peak plasma concentration was 1.9 mg/L after 0.6 h. Oral doses of 5, 10 and 15 mg/kg of a syrup formulation given to children achieved plasma concentrations of 0.26, 0.55 and 0.79 mg/L, respectively, after about 40 min. The half-life is around 2 h.
It is mainly eliminated in the bile; only about 2% appears in the urine. Its major metabolites are leucomycin A7, 10″-OH-rokitamycin (which show some antibacterial activity) and leucomycin V. In healthy adult volunteers, the proportions of rokitamycin and its metabolites in serum 30 min after a single oral dose of 1200 mg were 18% (leucomycin A7), 33% (10″-OH-rokitamycin) and 9% (leucomycin V). The pharmacokinetic behavior is not altered in patients with liver cirrhosis. It is available in Italy and Japan.
