Silver

(rINN)

💊 Chemical information

Argent; Argentum; E174; Plata; Silber.
Ag = 107.8682.
CAS — 7440-22-4.
ATC — D08AL30.
ATC Vet — QD08AL30.

💊 Profile

Silver is a pure white, malleable and ductile metal. It possesses antibacterial properties and is used topically either as the metal or as silver salts. It is not absorbed to any great extent and the main problem associated with the metal is argyria, a grey discoloration of the tissues. Silver is also present as the core in some copperwound plastic intra-uterine contraceptive devices. Silver is used as a colouring agent for some types of confectionery. Salts or compounds of silver that have been used therapeutically include silver acetate, silver allantoinate and silver zinc allantoinate, silver borate, silver carbonate, silver chloride, silver chromate, silver glycerolate, colloidal silver iodide, silver lactate, silver manganite, silver nitrate, silver-nylon polymers, silver protein, and sulfadiazine silver.

Homoeopathy.

Silver has been used in homoeopathic medicines under the following names: Argentum metallicum; Arg. met. Silver chloride has been used in homoeopathic medicines under the following names: Argentum muriaticum; Arg. mur. Silver cyanide has been used in homoeopathic compounds under the following names: Argentum cynatum; Arg. cy. Silver iodide has been used in homoeopathic medicines under the following names: Argentum iodatum; Arg. iod.

Argyria.

Argyria (generalised argyrosis), characterised by a slate, blue-grey discoloration of the skin, sclera, mucosal surfaces, and nails, developed in a patient who had used vasoconstrictor nasal drops containing silver protein for 4 years. The colour changes were most obvious in skin exposed to the sun. Argyria is irreversible and withdrawal of the nasal drops and use of other measures such as use of sun block and chemical peeling had little effect in this patient.1
1. Tomi NS, et al. A silver man. Lancet 2004; 363: 532.

Catheter care.

The benefits of silver coated or impregnated catheters in preventing or reducing urinary-tract infection are uncertain, and studies have provided conflicting evidence. Some1consider that the benefits are statistically insignificant. However, a meta-analysis2 involving 8 studies with a total of 2355 patients concluded, despite some concerns about the quality and heterogeneity of the studies, that there was a benefit, but that silver alloy coated catheters were significantly more effective in preventing urinary-tract infections than were those coated with silver oxide.
1. Reiche T, et al. A prospective, controlled, randomized study of the effect of a slow-release silver device on the frequency of urinary tract infection in newly catheterized patients. BJU Int 2000; 85: 54–9
2. Saint S, et al. The efficacy of silver alloy-coated urinary catheters in preventing urinary tract infection: a meta-analysis. Am J Med 1998; 105: 236–41.

Wound healing.

Silver is incorporated into topical dressings for wound care although a systematic review1 of 3 randomised controlled studies found insufficient evidence to support the use of silver-containing dressings or other formulations for the treatment of infected or contaminated wounds. Bacterial resistance to silver can occur, but this risk can be minimised by choosing dressings that release high levels of silver ions and have a rapid bactericidal action.2 The mechanism of bactericidal action of silver in dressings is that silver atoms are oxidised and slowly released as positively charged silver cations when in contact with fluid. The silver ions bind to and disrupt bacterial cell walls as well as binding to bacterial enzymes and DNA. A nanocrystalline silver coating to the dressing increases the surface area of exposure and facilitates release of silver ions. Silver can also be incorporated as complex silver molecules in various different topical formulations that regulate the speed of delivery.1 Proposed mechanisms of silver resistance have been plasmid acquisition and gene mutation.2
1. Vermeulen H, et al. Topical silver for treating infected wounds. Available in The Cochrane Database of Systematic Reviews; Issu
1. Chichester: John Wiley; 2007 (accessed 24/06/08)
2. Chopra I. The increasing use of silver-based products as antimicrobial agents: a useful development or a cause for concern? J Antimicrob Chemother 2007; 59: 587–90.

💊 Preparations

Proprietary Preparations

Braz.: Ultradina†; Fr.: Micropur†; Ger.: Contreet; Ital.: Acticoat; Katomed; UK: Avance; Contreet. Multi-ingredient: Arg.: Efodil†; Nova-T; Canad.: Nova-T; Chile: NovaT†; Fr.: Actisorb Ag ; Aquacel Ag; Biatain Argent; Micropur Forte DCCNa; Nova-T; Oligorhine; Release Ag; Ger.: Actisorb Silver†; Nova-T; Hong Kong: Nova-T; Indon.: Nova-T; Irl.: Actisorb Silver; Israel: Neocutan Silver; Nova-T; Ital.: Actisorb Plus; Agipiu†; Aquacel Ag; Katoxyn; Nova-T; Silvercel; Silverdres; Vulnopur; Malaysia: Nova-T; Mex.: Nova-T; Neth.: Nova-T†; NZ: Nova-T; S.Afr.: Nova-T; Singapore: Nova-T; Spain: Argentocromo†; Switz.: Argent†; Gyrosan†; Nova-T; Thai.: Nova-T†; Turk.: Nova-T; UK: Actisorb Silver; Nova-T; Venez.: Nova-T.
Published May 08, 2019.