Topical Wound Medications

Topical wound medications are used to apply on the wounds. these are antimicrobials and Antibiotics,Silver sulfadiazine, Aloe vera, Tripeptide-copper complex, Honey and sugar, Chlorhexidine Diacetate, Povidone-Iodine, Hydrogen peroxide, Dakin’s solution, Sterile normal saline etc.

Topical antimicrobials and Antibiotics

Antimicrobial agents and antibiotics eliminate or reduce the number of microorganisms in a wound that destroy tissue. Topical rather than systemic antibiotics are preferred for open wounds. Combined topical and systemic antibiotic therapy is advantageous in heavily contaminated wounds but not in mildly or moderately contaminated wounds. Antibiotics applied within 1-3 hrs of contamination often prevent infection. Benefits of topical drugs should outweigh their cytotoxic effects. Antibiotics used effectively as topical ointments or added to lavage solutions are penicillin, ampicillin, tetracycline, kanamycin, neomycin, bacitracin, polymyxin, and cephalosporins. 

Once infection is established, topical and systemic antibiotics have no beneficial effect in preventing suppuration of wounds undergoing closure. Wound coagulum prevents topical antibiotics from reaching effective levels in tissues deep in the wound and also prevents systemic antibiotics from reaching superficial bacteria. These wounds must be debrided to allow antimicrobial access to bacteria.

Topical steroids may inhibit epithelialization, wound contraction, and angiogenesis.  Production of exuberant granulation tissue may be reduced by the one or two application of corticosteroids. Topical anaesthetics may be used to reduce traumatic and postoperative pain.

In wound management topical antibiotics have got both advantage and disadvantage compared to antiseptics.

Advantages of topical antimicrobials and Antibiotics are Selective bacterial toxicity, efficacy in the presence of organic material, and combined efficacy with systemic antibiotics.

Disadvantages of topical antimicrobials and Antibiotics are expense, narrower antimicrobial spectrum, potential for bacterial resistance, creation of “super infections”, systemic or local toxicity, hypersensitivity, and increased nosocomial infections.

Triple antibiotic ointment

Triple antibiotic ointment consists of bacitracin, neomycin, and polymyxin and is effective against a broad spectrum of pathogenic bacteria commonly infecting superficial skin wounds. It is more effective for preventing infection than for treating them.

Silver sulfadiazine

Silver sulfadiazine is a 1% water miscible cream used as Topical wound medications and is effective against most gram-positive and gram-negative bacteria most fungi. It also serves as an antimicrobial barrier, can penetrate necrotic tissue, and enhances wound epithelialization. It is the drug of choice to treat burn wounds. Wound retardant effects have been reported in vitro studies in human. These effects are reversed when it is combined with aloe vera.

Nitrofurazone

Nitrofurazone (Furacin) has broad spectrum antibacterial and hydrophilic properties, the later enabling it to draw body fluid from wound tissue, which helps dilute tenacious exudates so they can be absorbed into bandages.  It delays wound epithelialization and loses some of its antimicrobial effects in the presence of organic matter.

Gentamicin sulphate

Gentamicin sulphate is available as a 1% ointment or powder (Garamycin), but solutions are preferred. It is especially effective in controlling gram-negative bacterial growth (Pseudomonas spp., Escherichia coli, Proteous organisms). It is often used for wounds that do not responded to triple antibiotic ointment.

Cefazolin

Cefazolin is effective against gram-positive and some gram-negative organisms. Topically administered cefazolin is 95% bioavailable and rapidly absorbed; therefore systemic levels equal wound fluid levels within 1 hour.

Mafenide (hydrochloride or acetate)

Mafenide (hydrochloride or acetate) is a topical sulfa compound available as an aqueous spray. It has a spectrum against gram-negative bacteria, including Pseudomonas and Clostridium, and is particularly useful on severely contaminated wounds.

Aloe vera

Aloe vera gel is extracted from the aloe leaf and contains 75 potentially active constituents. It has antimicrobial and antifungal activity. It is used on burns because of its antimicrobial effect on Pseudomonas aeruginosa. The antiprostaglandin and antithromboxane properties of aloe vera medications are beneficial in maintaining vascular patency and thus avert dermal ischemia. It has so many other activities on wound like stimulation of fibroblastic replication, penetration and anesthetizing tissue, promoting wound healing, stimulating tissue repair in suppurating wounds and resistant ulcers by promoting epithelial growth. Aloe vera counteracts the inhibitory effects of silver sulfadiazine when the two are combined.

Tripeptide-copper complex

Tripeptide-copper complex stimulates wound healing and is a chemoattractant for mast cells, monocytes, and macrophages, which stimulate debridement, angiogenesis, collagen synthesis, and epithelialization. The best time to begin tripeptide-copper complex application is the late inflammatory and early repair phases, with treatment continuing into later repair phase. Its greatest effect is in the first 7 days of its use. Exuberant granulation tissue may be a problem with this agent.

Honey and sugar

Honey is an old agent that has seen renewed interest. Its benefits include enhancing wound debridement, reducing edema and inflammation, promoting granulation tissue formation and epithelialization, and improving wound nutrition. It has an antimicrobial and a deodorizing effect. Like honey, sugar has similar hypertonic effects. Sugar is applied in a 1cm thick layer, and the wound is bandaged after debridement and lavage. Honey is applied by impregnating sterile gauze, which is then positioned on the wound and covered with a thick, absorbent bandage. They are indicated in the inflammatory and early repair phases of healing.

Wound Cleansing Solutions

Wound cleansing solution should have ideal antiseptic properties with minimal cytotoxicity. They are used primarily in the initial phases of wound management to decrease bacterial load and rid wounds of necrotic tissue and debris. Once the wound is clean, balanced electrolyte or physiologic saline solutions are ideal for cleansing it. Tap water is not an ideal wound cleanser, but is acceptable to initially remove dirt and debris when there is severe contamination. Its hypotonicity causes cell swelling, which can cause significant cell destruction and delay wound healing with prolonged use. Antiseptic solutions are contraindicated in clean wounds because all antiseptics have some cytotoxic effects and may do more harm than good.

Chlorhexidine Diacetate

Chlorhexidine Diacetate is a preferred wound lavage and wetting solution is 0.05% chlorhexidine diacetate because of its wide spectrum of antimicrobial activity and sustained residual activity. It has antibacterial activity in the presence of blood and other organic debris, has minimal systemic absorption and toxicity, and promotes rapid healing. Residual activity may last as long as 2 day, and effectiveness increases with repeat application. Potential drawbacks of chlorhexidine include resistance to Proteus, Pseudomonas, and Candida, and corneal toxicity.

Povidone-Iodine

1% or 0.1% povidone-iodine is used frequently for wound lavage because of its wide spectrum of antimicrobial activity. Iodine compounds are active against vegetative and sporulated bacteria, fungi, viruses, protozoa, and yeasts. A 0.1% solution is recommended. This concentration kills bacteria within 15 seconds, and there is no known bacterial resistance. Residual activity lasts only 4 to 8 hours and organic matter inactivates the free iodine in povidone-iodine. It is absorbed to the system through the skin and mucus thus excess systemic concentration causes transient thyroid dysfunction. Its low pH can cause or intensify metabolic acidosis when it is absorbed. Scrubbing wounds with povidone-iodine detergents damages tissues and potentiate infection.

Acetic acid

Acetic acid at 0.25% or 0.5% occasionally is used as lavage solution. Its antibacterial effect is achieved by lowering wound pH. It is more cytotoxic to fibroblasts than to bacteria.

Hydrogen peroxide

Hydrogen peroxide, even in low concentrations, damages tissue and is poor antiseptic. It is an effective sporicide. so it is not used as Topical wound medications on live tissue.

Dakin’s solution

Dakin’s solution is a 5% solution of sodium hypochlorite (1:10 dilution of laundry bleach). It is detrimental to neutrophils, fibroblasts, and endothelial cells and therefore should not be used as a wound lavage solution.

Sterile normal saline 0.9%

Sterile normal saline 0.9% widely used for irrigation of the wound.

Hyper tonic saline 2.5%

Hyper tonic saline 2.5% used for Cleaning & antibacterial activity on the wound.