Topical Antimicrobials: Polyhexamethylene Biguanide

Chronic wounds often require that more than one agent be used to treat the wound, depending on the stage of wound healing. You might often hear the term “bacterial load” to denote the amount of bacteria present in and on a wound. Bacterial load can have a deleterious effect on wound healing. All chronic wounds are believed to be contaminated to some degree with bacteria.  Depending on the amount of bacteria present, wounds may be classified as:

• Contaminated
• Colonized
• Critically colonized
• Infected

The first two categories, contamination and colonization, are not treated routinely with antibiotics. Wounds that are critically colonized should be treated, or they may progress to the infected stage. Wounds in the infected stage usually show all the classic signs and symptoms of infection; that is, erythema, edema, increased odour and pain, a rise in white blood cell count and a rise in temperature.  It is important to note that an infection may be clinically “silent” or unapparent.  Individuals who are immunocompromised or who have inadequate perfusion to the involved area are not only at greater risk for infection but also less likely to exhibit the classic signs of infection (Myers, Betsy, 2008).

 

What is Polyhexamethylene Biguanide?

PHMB is a commonly used antiseptic, and can be found in such substances as perioperative cleaning products, contact lens cleaning solutions, swimming pool cleaners, and the like. In-vivo and in-vitro studies have shown the safety and effectiveness of PHMB. PHMB interacts with the surface of the bacteria, and then is transferred to the bacteria’s inner cytoplasm and the cytoplasm membrane and eventually causes cell death.

 

There are several products commercially available which contain PHMB:

• Kerlix AMD99
• Excilon AMD99
• Telfa AMD99
• Xcell AE Cellulose Wound Dressing

Such products are intended for use on partial-and-full thickness wounds. Advantages of these dressings are that  they:

• absorb wound exudate
• support autolytic debridement of non-viable tissue
• provide a moist wound bed
• reduce pain

In addition, PHMB has been shown to be effective against MRSA, Enterococcus faecalis, Candida albicans, Eschirichia coli, and Bacillus subtilis.

 

Polyhexamethylene biguanide (PHMB) has been studied in recent literature and no evidence of resistance to PHMB has been observed.

 

Cost-Effectiveness of PHMD

Estimated costs associated with treating chronic wounds are estimated to be around $40,000.00, including the costs of supplies and services. Any delay in wound healing, such as occurs when wounds become infected, will increase the cost associated with care. Studies have shown that the cost of PHMD is similar to that of other advanced dressings.

 

“Currently, PHMB does not have a history of resistance or cytotoxicity, has demonstrated promotion of healing, and may play a new and important role as an antimicrobial agent in dressings” (Cavorsi, Lee, & Mulder, 2007).

 

Polyhexamethylene biguanide is one of a series of wound care treatments we are happy to present you with at WoundEducators.com. If you are interested in taking the next step and becoming wound care certified, please contact us.