Misconcepts in the Usage of Wound Matrices with AntiMicrobials

Why doctors avoid antibiotics?

Seeing a patient, doctors do not prefer to prescribe an AntiMicrobial normally. It is given as the last resort. The reasons are

1. 1. To avoid development of resistance
   2. It might cause other metabolic complications
   3. Some antimicrobials could be carcinogenic or even genotoxic
   4. Excretion of antimicrobials for long duration could cause kidney damage

Role of AntiMicrobials in Wound matrices:

There are certain misconcepts prevail in the usage of AntiMicrobials in wound matrices. Selection of an ideal tissue regenerative, non-immunogenic and biocompatible matrix is quite significant.  To such a bioactive material, adding an AntiMicrobial as a prophylactic measure might impede the healing rate in non-infected wounds.  Let’s focus on the scientific facts and the misconcepts of using wound matrices with AntiMicrobials.

Fig 1: Effect of overprescribed antimicrobial in a non infected ulcer

Misconcept 1:

Possibility of developing resistance to antibiotics:
Majority of the antimicrobial wound healing matrices are impregnated with ionic and metallic silver, iodine, Polyhexamethylene biguanide (PHMB), doxycycline, ciprofloxacin, levofloxacin (ref 1) in addition to tetracycline. In the treatment of a non-infected wound using an antimicrobial dressing (as a prophylactic measure) may not be appropriate. Moreover, frequent application of wound matrices with AntiMicrobials may result in the development of resistance to AntiMicrobials by the pathogens.

Solution: Pre-incorporation of antimicrobial in the biological matrices may be avoided. The required quantity of relevant agent based on the microbial species can be added by the Surgeon or the Nurse.

Misconcept 2:

AntiMicrobials may cause metabolic complications:
Some AntiMicrobial agents like Silver and Polyhexamethylene biguanide (PHMB) may trigger unwanted severe immunological response that might impede certain metabolic functions. In patients with known sensitivity to silver, using wound matrices loaded with silver may result in allergic reaction (silver toxicity). On the other hand, certain AntiMicrobials like PHMB may have a drastic effect on the cell growth and function like inducing tumor or even mutation.

Fig 2: Skin allergy induced by AntiMicrobials

Solution: It is better to avoid using silver based dressing in patients susceptible to allergic reaction. Usage of cell-destructive AntiMicrobials can be intervened with AntiMicrobial agents causing little to no metabolic complications only when the situation demands. Alternatively, it is better to use a native, un-cross linked biocompatible material as a wound matrix.

Misconcept 3:

Certain antibiotics may be carcinogenic or genotoxic:
The Directive 67/548/EC of the European Parliament has classified the AntiMicrobial agent Polyhexamethylene biguanide (PHMB) incorporated in certain wound matrices to be carcinogenic (Carc 2 H351 suspected of causing cancer) according to Annex VI of Regulation (EC) No. 1272/2008 (ref 2). This clearly indicates PHMB to be a potentially harmful AntiMicrobial upon both dermal and oral administration.

Solution:Avoid pre incorporated antimicrobials that are suspected carcinogens or genotoxins. Just use a bioactive biocompatible non-immunogenic matrix as the biological skin substitute with addition of antimicrobial drug when needed.

Misconcept 4:

Possibility of Kidney damage due to long-term excretion of un-used AntiMicrobials:
Taking AntiMicrobials for long duration can affect the kidney cells (Nephrons) during excretion (ref 3). The Nephrons are highly sensitive to the toxic effect of the AntiMicrobials. Moreover, in patients with known sensitivity to AntiMicrobial agents like silver, it may trigger an allergic reaction that can affect the Kidneys.

Fig 3: Types of Antibiotics filtered by different regions in the Kidney

Solution: Long-term usage of Antimicrobials must be avoided. The dosage of AntiMicrobial agent administered must match the clinical requirements. A thorough screening of the type of species can help understand the type and quantity of AntiMicrobial to be given. It is always better to choose a non-immunogenic biomaterial free from potential allergens like Elastin, Proteo-glycans etc.

Misconcept 5:

Use of wound matrices with AntiMicrobials in a non-infected wound may impede the rate of healing:
Using AntiMicrobial incorporated wound healing matrices in treating non-infected wounds may not be appropriate. It might reduce the rate of wound healing leading to delayed wound closure. Moreover, it may destroy the helpful skin microbiome.

Solution: Pre-impregnated wound matrices must not used in treating a non-infected wound. Rather, the rate of wound healing can be enhanced by using a un-cross linked, biocompatible and non-immunogenic tissue regenerative matrix.

Conclusion:
Doctors are trained to provide the right medication relevant to the condition reported. But, in order to satisfy the patients, they often overprescribe medicines like antimicrobials. In case of non-infected wound, use of antimicrobial impregnated tissue regenerative matrices may directly lead to potential problems like delayed wound healing and multi-drug resistance. Having said this, it is the duty of Clinicians to explain the relevance of antimicrobial prescription and it is important that the consumer is aware of the scientific misconcepts.