Amoxycillin is better than ampicillin due to:
Amoxicillin It is a close congener of ampicillin (but not a prodrug); similar to it in all respects except: * Oral absorption is better; food does not interfere with absorption; higher and more sustained blood levels are produced. * Incidence of diarrhoea is lower. * It is less active against Shigella and H. influenzae. Many physicians now prefer it over ampicillin for bronchitis, urinary infections, SABE and gonorrhoea. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:701
Chemotherapy
Better biovailability if taken with food
Lesser biovailability if taken with food
Incidence of diarrhea is higher
More active against Shigella and H. influenza
Better biovailability if taken with food