Silver Pharmacology: Past, Present and Questions for the Future

Abstract

Silver pharmacology is at the cross-roads. It has a long history as a chemosterilent but is currently denigrated by some vested interests and other ‘knowledge monopolies’. It deserves better—particularly in these critical times of ever mounting incidence of antibiotic resistance. This reappraisal outlines some approaches to a dispassionate debate as to why we should, or should not, be reconsidering silver as an addition to (not a substitute for) other antibiotics at the front line of medicine. This will require more understanding about (i) the chemistry of silver in a biological environment; (ii) the different physical and bio-reactive properties of ionised silver (Ag(I)) and nanoparticulate metallic silver (Ago); (iii) the antibiotic potential of both Ag(I) and Ago; and (iv) establishing objective Quality Controls for potential silver therapies. Six appendices (A–F) provide some technical data and focus further upon the need to clearly define (a) procedures for manufacturing nanoparticulate metallic silver (NMS); and (b) the purity and properties of NMS preparations—especially stability, antibiotic efficacy and safety of products offered for clinical evaluation. A further appendix (G) deals with some political considerations currently impeding impartial clinical research on silver therapeutics.