Colloidal silver

The medical uses of silver include its use in wound dressings, creams, and as an antibiotic coating on medical devices. Wound dressings containing silver sulfadiazine or silver nanomaterials may be used on external infections. The limited evidence available shows that silver coatings on endotracheal breathing tubes may reduce the incidence of ventilator-associated pneumonia. There is tentative evidence that using silver-alloy indwelling catheters for short-term catheterizing will reduce the risk of catheter acquired urinary tract infections. The medical uses of silver include its use in wound dressings, creams, and as an antibiotic coating on medical devices. Wound dressings containing silver sulfadiazine or silver nanomaterials may be used on external infections. The limited evidence available shows that silver coatings on endotracheal breathing tubes may reduce the incidence of ventilator-associated pneumonia. There is tentative evidence that using silver-alloy indwelling catheters for short-term catheterizing will reduce the risk of catheter acquired urinary tract infections. Silver generally has low toxicity, and minimal risk is expected when silver is used in approved medical applications. Alternative medicine products such as colloidal silver are not safe or effective. Silver and most silver compounds have an oligodynamic effect and are toxic for bacteria, algae, and fungi in vitro. The antibacterial action of silver is dependent on the silver ion. The effectiveness of silver compounds as an antiseptic is based on the ability of the biologically active silver ion (Ag+) to irreversibly damage key enzyme systems in the cell membranes of pathogens. The antibacterial action of silver has long been known to be enhanced by the presence of an electric field. Applying an electric current across silver electrodes enhances antibiotic action at the anode, likely due to the release of silver into the bacterial culture. The antibacterial action of electrodes coated with silver nanostructures is greatly improved in the presence of an electric field. Silver, used as a topical antiseptic, is incorporated by bacteria it kills. Thus dead bacteria may be the source of silver which may kill additional bacteria. Silver sulfadiazine (SSD) is a topical antibiotic used in partial thickness and full thickness burns to prevent infection. It was discovered in the 1960s, and was the standard topical antimicrobial for burn wounds for decades. However systemic reviews in 2014, 2017 and 2018 concluded that more modern treatments, both with and without silver, show better results for wound healing and infection-prevention than silver sulfadiazine, and therefore SSD is no longer generally recommended. SSD is still on the World Health Organization's List of Essential Medicines (updated as of August 2017) as one of the most effective and safe medicines needed in a health system, and the US Food and Drug Administration has approved a number of topical preparations of silver sulfadiazine for treatment of second-degree and third-degree burns. A 2018 Cochrane review found that silver-containing dressings may increase the probability of healing for venous leg ulcers. A 2017 meta-analysis of clinical studies over the period of 2000-2015 concluded that 'the evidence base for silver in wound management is significantly better than perceived in the current scientific debate' and that, if applied selectively and for short periods of time, silver has antimicrobial effects, produces an improvement in quality of life and shows good cost-effectiveness. A 2014 data set from a recent meta-analysis concluded that the use of silver dressings improves healing time, and can lead to overall cost savings compared with treatment with non-silver dressings. It also found that patients who had been treated with silver dressings had a faster wound closure compared with patients who had been treated with non-silver dressings. A 2013 meta-analysis of Randomised Controlled Trials found 'statistical significant evidence' to support the use of Biatain Silver dressings in treating venous leg ulcers. A number of wound dressings containing silver as an anti-bacterial have been cleared by the U.S. Food and Drug Administration (FDA).