Skin Conditions, General | January 22, 2015 | Author: The Super Pharmacist
Topical antiseptics are antimicrobial agents that kill, inhibit or reduce the number of microorganisms and are important in the control of wound infections (1). However, their effectiveness and safety are a matter of ongoing debate: some over the counter, commonly used antiseptics are underpinned by very little evidence to suggest they are of benefit, and caution is exercised over their use in certain situations due to their potential toxicity to cells (cytotoxicity) (2).With an increasing number of antibiotic-resistant pathogens, and questionable effectiveness of existing therapies, considering the evidence underpinning a wide range of available treatment options is paramount.
Available commercially in a number of solutions, creams, ointments, dressings and dry powder for the treatments of wounds and abrasions. As a skin disinfectant, its efficacy is clear and well documented. A wide range of studies (often undertaken in vitro, not directly on patients) have demonstrated its ability to lethally damage bacterial cells (3,4,5). Clinically, there are more questions regarding its safety and efficacy in helping wounds heal. For short term use on small wounds, the evidence suggests that it decreases infection rates, reduces bacterial load and promotes wound healing (6). However, for longer term use on larger wounds, absorption of PVP-I has been shown to be detrimental to health in some patients (7).
The number of studies highlights its potential for longer-term damage support the notion that PVP-I should only be used sparingly on small superficial wounds. This tends to be reflected in a wide variety of guidelines in different countries, where PVP-I is recommended for the treatment of small acute wounds and forbidden in the treatment of larger wounds such as pressure sores or wounds caused by burns.
Chlorhexidine has been in clinical use for over 60 years and its mode of action has been studied extensively (8). However, this does not translate into clinical trials that evaluate its effectiveness in the treatment of wounds. A recent systematic review of all available evidence, in both human and animal studies, suggested that there is insufficient evidence to assess its efficacy (9). There is reasonable evidence to support the assertion that it has no adverse effects on healing (10). As with PVP-I, there are a number of reports that suggest chloroexidine also decreases bacterial accounts and increases healing rates. However, the general consensus in the pharmaceutical regulatory community is that more clinical trials are required before it can be either recommended or condemned as a viable treatment option for open wounds. These bodies also recognise growing concern over the development of antiseptic resistance in some studies involving chlorhexidine (11).
Chloroxylenol is not significantly toxic to humans and has been in use since its development in Europe in the 1920s (12), although a number of studies have documented its status as a mild irritant that can result in a number of allergic reactions (13). A limited amount of case studies have considered the impact of large amounts of chloroxylenol and found that some individuals have efficient natural mechanisms for rapidly detoxifying and eliminating it from the body, although the study did not consider the long term effects of large dose application (14). There is very little formal literature specifically concerned with the role of chloroxylenol as a topical antiseptic, and well-designed, larger studies are required to investigate its efficacy. Of the limited studies that do exist, many do not define the type of patients and wounds included, have inappropriate control groups or sample sizes that are not large enough to be significant (15).
Mupirocin has been evidenced to have minimum toxicity when applied to small wounds, with no cross resistance. It is regularly used ‘off-label’ for the treatment of chronic wounds (especially if MRSA is present), although there is no evidence regarding its effectiveness for this purpose, or indeed its safety (16).
There have been a number of studies that suggest mupirocin has low levels of toxicity for treating common skin conditions:
a clinical study undertaken in America in 2010, observing the role of mupirocin in treating atopic dermatitis, found it to be safe and have similar levels of efficacy to orally administered antibiotics or topical fusidic acid (17).
It has a high degree of potency against gram-positive bacteria commonly found in patients with a range of skin conditions, and is considered a valuable addition to the topical antiseptic market in light of increasing levels of antimicrobial resistance.
The basis for comparing the efficacy of topical antiseptics is made difficult by a range of variables that are often non-standardised or poorly controlled. Much of the evidence that underpins topical antiseptics is undertaken in a laboratory environment where antimicrobial agents are subject to a Minimum Inhibitory Concentration (MIC) to determine their potency, the concentration tested, lab temperature, length of contact time. These specifications often vary by country, making direct comparison difficult (18). Similarly, many studies regarding antiseptics and wound control often focus on very small sample groups and provide little detail regarding topical dose, nature of the wound, details of the control group and test conditions.
Antibiotic-resistant strains of pathogens may play a significant role in the ineffectual control of wound infections with currently available topical antiseptics. As such, more well-designed studies are required to ensure that topical antiseptics are not being misused or abused by both healthcare professionals and patients alike. The development of resistance to chlorhexidine and other widely used antimicrobial agents (19) also highlights the importance of diversifying the range of topical therapies available to treat a range of infections.
1. Atiyeh BS, Dibo SA, Hayek SN. (2009). Wound cleansing, topical antiseptics and wound healing. Int Wound J 6(6):420-30
2. Duc QI, Breetveld M, Middelkoop E, Scheper RJ, Ulrich MM, Gibbs S. (2007). A cytotoxic analysis of antiseptic medication on skin substitutes and autograft. Br J Dermatol 157(1):33-40 Epub
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4. Traore O, Fayard SF, Laveran H. (1996). An in-vitro evaluation of the activity of povidone-iodine against nosocomial bacterial strains. J Hosp Infect 34(3)217-22
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9. Payne DN, Babb JR, Bradley CR. (1999). An evaluation of the suitability of the European suspension test to reflect in vitro activity of antiseptics against clinically significant organisms Lett Appl Micro 28: 7-12
10. Drosou A, Falabella A, Kirsner RS. (2003). Antiseptics on wounds: an area of controversy. Wounds 15(5)149-66
11. McDonnell G, Russell AD. (1999). Antiseptics and disinfectants: activity, action, and resistance. Clin Microbiol Rev 1999; 12(1)147-79
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13. Verma GK, Mahajan VK, Shanker V, Tegta GR, Jindal N, Minhas S. (2011). Indian J Dermatol 77(5)612-4
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15. Lipsky BA, Hoey C. (2009). Topical antimicrobial therapy for treating chronic wounds. Clin Infect Dis 49(10)1541-1549
16. Terpenning MS, Bradley SF, Wan JY, Chenoweth CE, Jorgensen KA, Kauffman CA. (1994). Colonization and infection with antibiotic-resistant bacteria in a long-term care facility. J Am Geriatr Soc 42:1062-9
17. Moody MN, Morrison LK, Tyring SK. (2010). Retapumulin: what is the role of this topical antimicrobial in the treatment of bacterial infections in atopic dermatitis? Skin Therapy Lett 15(1)1-4
18. Payne DN, Babb JR, Bradley CR. (1999). An evaluation of the suitability of the European suspension test to reflect in vitro activity of antiseptics against clinically significant organisms. Lett Appl Micro 28: 7-12
19. McDonnell G, Russell AD. (1999). Antiseptics and disinfectants: activity, action, and resistance. Clin Microbiol Rev 1999; 12(1)147-79