See also Antibiotics (General)
Amoxicillin is a relative of the antibiotic penicillin, but has been modified to have a broader spectrum of effect.
According to two studies, the supplement bromelain (from pineapple stems) may increase the absorption of amoxicillin. 1,2 This effect might help the antibiotic work better.
There are concerns that antibiotic treatment might reduce levels of vitamin K in the body. However, this effect seems to be slight, and only significant, if at all, in individuals who are already considerably deficient in vitamin K. 3–6
References
REF1 Tinozzi S and Venegoni A. Effect of bromelain on serum and tissue levels of amoxicillin. Drugs Exp Clin Res 4: 39–44, 1978.
REF2 Luerti M and Vignali M. Influence of bromelain on penetration of antibiotics in uterus, salpinx and ovary. Drugs Exp Clin Res 4: 45–48, 1978.
REF3 Cohen H, Scott SD, Mackie IJ, et al. The development of hypoprothrombinaemia following antibiotic therapy in malnourished patients with low serum vitamin K 1 levels. Br J Haematol 68: 63–66, 1988.
REF4 Conly J and Stein K. Reduction of vitamin K 2 concentrations in human liver associated with the use of broad spectrum antimicrobials. Clin Invest Med 17: 531–539, 1994.
REF5 Shearer MJ, Bechtold H, Andrassy K, et al. Mechanism of cephalosporin-induced hypoprothrombinemia: relation to cephalosporin side chain, vitamin K metabolism, and vitamin K status. J Clin Pharmacol 28: 88–95, 1988.
REF6 Goss TF, Walawander CA, Grasela TH, et al. Prospective evaluation of risk factors for antibiotic-associated bleeding in critically ill patients. Pharmacotherapy 12: 283–291, 1992.