Innovative Treatment for DFU's with Osteomyelitis

In an article in this month’s issue of Expert Opinion in Drug Delivery, (Informa UK Ltd) a group of US experts in the management of diabetic foot ulcers (DFU) has identified Collatamp G (Theramed Corp, Mississauga) as a promising and superior system for delivering high concentrations of broad-spectrum antibiotic directly to the ulcer for patients with Infected Diabetic Foot Ulcers. While Collatamp G is not yet available for use in the USA, it was approved by Health Canada in 2007, and since 2008 has been used increasingly in Canada for the treatment of serious Diabetic Ulcers.

Dr. P. Mayer, Medical Director of The Mayer Institute (www.themayerinstitute.ca) in Hamilton, Ontario which specializes in advanced diabetic foot and wound care, performed a trial of Collatamp G on 15 of his most serious cases. “We used Collatamp G on several chronic deep wounds associated with osteomyelitis with excellent result. By providing a direct assault on the infected bone, Collatamp G dramatically improved healing in chronic, non-healing wounds and in at least 3 instances Collatamp G was key in helping us prevent amputations”.

From his research and experience, Dr. Mayer concurs with the study’s conclusion and further states that “adoption of Collatamp G into the treatment protocol for advanced diabetic foot ulcers, could dramatically reduce the length of disability for these patients, and also reduce healthcare costs by reducing the need for daily home-care visits to once or twice weekly.”

The Collatamp G product concept and technology is featured in an article co-authored by David G Armstrong and Andrew Boulton et al in this month’s Expert Opinion on Drug Delivery (full reference: The use of gentamicin-impregnated foam in the management of diabetic foot infections: a promising delivery system?; Catherine D Griffis, Stuart Metcalfe, Frank L Bowling, Andrew JM Boulton, David G Armstrong, Expert Opinion on Drug Delivery, June 2009, Vol. 6, No. 6, Pages 639-642).

Improved and shortened time to healing in Diabetic Foot Ulcers can have significant implications to patients at risk of limb amputation, as well as to the healthcare system as a whole. Chronic Diabetic Foot Ulcers are a major cause of Home Care visits and Disability claims to health insurance providers. Accelerating the healing process can reduce the overall burden on the healthcare system by getting the patient back to work sooner. One of the major goals in management of Diabetic Foot Ulcer is ‘Limb salvage’, that is, the prevention of limb amputation, which is both costly and devastating to patients and their families.

Because diabetic foot ulcers are often complicated by infection, antibiotic therapy is an important component in the management of the wound. Unfortunately traditional systemic antibiotics do not result in sufficient concentrations at the target tissue due to a number of factors, including the poor micro and macro circulation present in people with diabetes, and the risk of toxicity associated with adequate doses. Because of these and other limitations of systemic antibiotics, the authors of the paper note that “topical [or local antimicrobial therapy in the management of infected foot ulcers has been supported by several authors” , whom they then cite. The authors also note that compared with other local delivery systems, Collatamp G has been shown in European studies to be the clinically and economically “superior delivery mechanism”

About Collatamp G:

Collatamp G (www.collatampg.ca) is a biodegradable and fully resorbable Gentamicin-Collagen Sponge. Upon application to a wound, the product releases gentamicin, a broad-spectrum, aminoglycoside antibiotic (having a concentration-dependent mechanism of action), for local action. This achieves a high concentration of drug at the target tissue, while maintaining low systemic levels well below the toxicity threshold. Collatamp G was approved by Health Canada in 2007, and has since been used in hundreds of Canadian surgical procedures and Diabetic Foot treatments in over 40 Canadian Hospitals and Clinics.

About Infected Diabetic Foot Ulcers:

According to the Centers for Disease Control and Prevention (CDC), the estimated incidence of diabetes in the US exceeds 1.5 million new cases annually, with an overall prevalence of 20.8 million people, or 7% of the US population. By 2030, the International Diabetes Federation predicts that the Global prevalence of diabetes will almost double from 193 million people (estimated in 2003) to 366 million.

An estimated 15% of patients with diabetes will develop a lower extremity ulcer during the course of their disease. According to a large prospective study, approximately 7% of diabetic patients with foot ulcers will require an amputation. Diabetes is responsible for 75% of the non-traumatic lower limb amputations performed yearly in Canada. After a diabetic lower-limb ampuitation, 50% of patients will have their other limb amputated within 2 years. The mortality rate after limb amputation approaches 80% – a death rate second only to lung cancer (86%). The estimated cost of foot ulcer care in the US ranges from $4,595 per ulcer episode to more than $28,000, for the 2 years post diagnosis. The total annual cost of foot ulcer care in the US has been estimated to be as high as $5 billion.

Chronic ulcerations are often colonized or contaminated with bacterial pathogens that can prevent ulcers from healing. Many such wounds become clinically infected and require treatment with antibiotics. However, early diagnosis of diabetic foot infections is a clinical challenge as typical signs and symptoms of infection, such as pain, redness, or elevated circulating inflammatory markers, can be absent in individuals with neuropathic or neuroischaemic ulcers. Failure to diagnose and treat such infections can lead rapidly to the infection spreading, with the possibility of tissue necrosis, gangrene, osteomyelitis, and ultimately the prospect of a lower leg amputation.

Currently there are no antibiotics on the market specifically indicated for the prevention of diabetic foot infections. There is also reluctance by practitioners to use existing, systemically-acting antibiotics prophylactically because of concerns with systemic side effects and fear of propagating bacterial resistance with widespread use. Furthermore, diabetic ulcers are often associated with vascular disease and restricted peripheral blood flow, which may render systemically acting antibiotics less effective. By achieving very high localized concentrations of antibiotic, Collatamp G is designed to overcome these concerns.