<p>The thiol group of Acetylcysteine can reduce the efficacy of certain antibiotics such as ampicillin, tetracycline, macrolides, cephalosporins, aminoglycosides and amphotericin. Concomitant use of Acetylcysteine and amoxicillin will increase the level of the antibiotic in tissues. It is, therefore, advisable to use the two medicines 2 hours apart from each other. Acetylcysteine can increase the inhibitory effect of thrombocyte aggregation and vasodialation by nitroglycerine.</p>