Françoise Van Bambeke

Roxithromycin

In: KUCERS' THE USE OF ANTIBIOTICS: A CLINICAL REVIEW OF ANTIBACTERIAL,
ANTIFUNGAL, ANTIPARASITIC AND ANTIVIRAL DRUGS
6TH EDITION

VO·LUME 1, pages 770-778

2010 Edward Arnold (Publishers) Ltd,

Roxithromycin (CAS number: 80214-83-1) is a semisynthetic
macrolide derived from erythromycin A (9-[O-[(2-methoxyethoxy)methyl]
oxime]) (Chantot et al., 1986; Kirst and Sides, 1989a). The
empirical formula is C41H76N2015 and the molecular weight is 837.05.

Its chemical structure is shown in Figure 60.1. Its in vitro antibacterial
activity is similar to that of erythromycin, with similar or slightly higher
minimal inhibitory concentrations (MICs) (Pechere and Auckenthaler,
1987; Barry et al., 1988), and complete cross-resistance with
erythromycin (Barlam and Neu, 1984; Pechere and Auckenthaler,
1987; Barry et al., 1988).

Roxithromycin differs from erythromycin by an improved pharmacokinetic
profile, characterized by (1) higher acid stability, due to
replacement of the keto group in position 9 by an N-oxime side chain
which prevents the intramolecular hemiketalization reaction (Kirst
and Sides, 1989b); (2) i.mproved oral bioavailability and higher serum
levels; and (3) a prolonged half-life allowing for once-daily (300 mg) or
twice-daily (150mg bid) administration (Nilsen, 1987; Puri and
Lassman, 1987)