to order (prescription
Polioxyethylene-polioxypropylene co-polymer, polyvinyl pyrrolidone,
hydroxypropyl cellulose, precipitate silica, corn starch, magnesium stearate,
talc, propylene glycol, anhydrous glucose, methylhydroxypropyl cellulose,
Adverse Effects and Precautions
Gastro-intestinal disturbances are the most
frequent adverse effect, but are less frequent than with erythromycin. A case of
cholestatic hepatitis has been reported. Rashes, headache, dizziness, weakness
and changes in blood cell counts have also occurred. Acute pancreatitis, with
duodenal inflammation, pain, pancreatic enlargement and raised serum-amylase
developed within 24 hours of substitution of roxithromycin for erythromycin
ethyl succinate in a patient being treated for respiratory tract infection.
Symptoms resolved rapidly once roxithromycin was withdrawn. Souweine B, et al.
Acute pancreatitis associated with roxithromycin therapy. DICP Ann Pharmacother
1991- 25: 1137.
Antimicrobial Action and Resistance
It is reported to be as active or slightly less
active than erythromycin. MICs for the most sensitive strains range from about
0.03 to 1 mcg per ml but organisms with MICs up to about 2 mcg per ml are
generally considered sensitive.
Following oral administration roxithromycin is
well absorbed, with peak concentrations of about 6 to 8 mcg per ml occurring
around 2 hours after a single dose of 150 mg. Absorption is reduced when taken
after, but not before, a meal. It is widely distributed in tissues and body
fluids. It is reported to be about 96% bound to plasma protein (mainly alpha
(1)-acid glycoprotein) at trough concentrations, but binding is saturable, and
only about 86% is bound at usual peak concentrations.
Small amounts of roxithromycin are metabolized in
the liver, and the majority of a dose is excreted in the faeces as unchanged
drug and metabolites- about 7 to 12% is excreted in urine, and up to 15% via the
lungs. The elimination half-life is reported to range between about 8 and 13
hours, but may be more prolonged in children.
1. Puri SK, Lassman HB.
Roxithromycin: a pharmacokinetic review of a macrolide. J Antimicrob Chemother
1987- 20 (suppl B): 89-100.
2. Periti P, et al. clinical pharmacokinetic
properties of the macrolide antibiotics: effects of age and various
pathophysiological states (part II). Clin Pharmacokinet 1989- 16: 261-82.
Uses and Administration
Roxithromycin is a macrolide antibiotic with
actions and uses similar to those of erythromycin. It is given by mouth in a
dose of 150 mg twice daily before meals, in the treatment of susceptible
1. Phillips I, et al., (eds). Roxithromycin: a new macrolide. J
Antimicrob Chemother 1987- 20 (suppl B): 1-187.
2. Young RA, et al.
Roxithromycin: a review of its antibacterial activity, pharmacokinetic
properties and clinical efficacy. Drugs 1989- 37: 8-41. Correction. ibid.
Bahal N, Nahata MC. The new macrolide antibiotics: azithromycin, clarithromycin,
dirithromycin, and roxithromycin. Ann Pharmacother 1992- 26: 46-55.
Roxithromycin has been reported to be of benefit
in patients with late-stage symptoms (neuroborreliosis, (1) arthritis (2)) of
Lyme disease, given in combination with co-trimoxazole, although the
contribution of the latter is uncertain. (3)
1. Gasser R, Dusleag J. Oral treatment of late
borreliosis with roxithromycin plus co-trimoxazole. Lancet 1990- 336: 1189-90.
2. Pedersen LM, Friis-Moller A. Late treatment of chronic Lyme arthritis. Lancet
1991- 337: 241.
3. Bowman CA. Oral treatment of late borreliosis with
roxithromycin plus co-trimoxazole. Lancet 1990- 336: 1514.
to order (prescription