No effect of oral N-acetylcysteine on the bioavailability of erythromycin and
bacampicillin. 0. Paulsen, L. Borgstrom, B. Kdgedal, M. Walder.
ABSTRACT: In vitro studies with N-acetylcysteine (NAC) solutions used for
inhalation treatment have demonstrated inactivation of some antibiotics by
NAC. Oral NAC treatment is increasingly common for long-term prophylaxis
in chronic bronchitis. During exacerbations, treatment with oral antibiotics will
often be given simultaneously. We assessed the effect of simultaneous oral
administration of NAC on the bioavailability of two antibiotics in ten healthy
volunteers. No effect of NAC was found on the bioavailability of ampicillin,
after administration of the prodrug bacampicillin. A slight, but not significant
statistical increase in erythromycin serum levels was seen with NAC. Acetylator
phenotype did not influence the absorption of NAC, which seemed slightly
reduced by bacampicillin, but significantly increased by erythromycin. No
decrease of antibacterial activity of sera was found in vitro after the add.ition of
NAC or the related thiol glutathione, employing micrococcus Juteus and
staphylococcus aureus as indicator organisms.