Topical Phenytoin Application in Grade I and II Diabetic Foot Ulcers: A Prospective Study

Effectiveness of interventions to enhance healing of chronic foot ulcers in diabetes: A systematic review

BACKGROUND

It is critical that interventions used to enhance the healing of chronic foot ulcers in diabetes are backed by high-quality evidence and cost-effectiveness. In previous years, the systematic review accompanying guidelines published by the International Working Group of the Diabetic Foot performed 4-yearly updates of previous searches, including trials of prospective, cross-sectional and case-control design.

AIMS

Due to a need to re-evaluate older studies against newer standards of reporting and assessment of risk of bias, we performed a whole new search from conception, but limiting studies to randomised control trials only.

MATERIALS AND METHODS

For this systematic review, we searched PubMed, Scopus and Web of Science databases for published studies on randomised control trials of interventions to enhance healing of diabetes-related foot ulcers. We only included trials comparing interventions to standard of care. Two independent reviewers selected articles for inclusion and assessed relevant outcomes as well as methodological quality.

RESULTS

The literature search identified 22,250 articles, of which 262 were selected for full text review across 10 categories of interventions. Overall, the certainty of evidence for a majority of wound healing interventions was low or very low, with moderate evidence existing for two interventions (sucrose-octasulfate and leucocyte, platelet and fibrin patch) and low quality evidence for a further four (hyperbaric oxygen, topical oxygen, placental derived products and negative pressure wound therapy). The majority of interventions had insufficient evidence.

CONCLUSION

Overall, the evidence to support any other intervention to enhance wound healing is lacking and further high-quality randomised control trials are encouraged.

Topical phenytoin administration accelerates the healing of acetic acid-induced colitis in rats: evaluation of transforming growth factor-beta, platelet-derived growth factor, and vascular endothelial growth factor

Ulcerative colitis (UC), limited to the colon's innermost lining, has become a global health problem. Immunomodulatory and monoclonal antibodies are used to treat UC despite their side effects and limitations. Phenytoin is used to heal wounds owing to its effects on growth factors, collagen, and extracellular matrix synthesis. This study aimed to evaluate the effect of topical phenytoin administration in UC. Phenytoin was administered in two doses during the treatment. Eighty male Wistar rats (230-280 g) were divided randomly into ten groups of sham, control, hydrocortisone, phenytoin 1%, and 3% groups in 6- or 12-day treatment protocols. The UC model was induced by the administration of acetic acid 4% into the colon. Animals were killed on the 7th and 13th postoperative days. The main outcome measures included body weight loss, microscopic score, and ulcer index measured using specific criteria. Growth factors were measured by western blotting. Results illustrated that body weight loss was reversed in the treatment groups. Ulcer index had decreased on 6- and 12-day treatment protocols. Microscopic scores in 6-day enema treatment significantly decreased compared to the control groups. Transforming growth factor-beta (TGFβ) significantly increased in a time-dependent manner and platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) significantly increased in a time- and dose-dependent manner in phenytoin 1% and 3% in the 6- and 12-day protocols. Phenytoin dose- and time-dependently reversed weight loss. In addition, histopathological parameters included microscopic scores, and the ulcer index was decreased through the induction of growth factors TGFβ, PDGF, and VEGF and consequently accelerated ulcer healing.

Novel topical esmolol hydrochloride improves wound healing in diabetes by inhibiting aldose reductase, generation of advanced glycation end products, and facilitating the migration of fibroblasts

AIMS/OBJECTIVES

Wound healing in people with diabetes is delayed secondary to impaired nitric oxide generation, advanced glycation end products (AGE), and poor migration of epithelial cells. We developed a novel topical esmolol hydrochloride (Galnobax) and assessed its efficacy for wound healing in streptozocin-induced diabetic hairless rat.

METHODS

All experiments were performed at an animal laboratory and tertiary-care research facility. Ex vivo aldose reductase inhibition was assessed from enzymes obtained from a bacterial culture (spectrophotometer), sorbitol content in homogenized red blood cells, and AGE in glucose and bovine serum by fluorometry following the addition of esmolol in varying concentrations. A scratch assay of human fibroblasts, endothelial cells, and keratinocytes was assessed under a high-glucose environment and after esmolol by phase-contrast microscopy. The efficacy evaluation of the topical application of Galnobax (14 and 20%) or vehicle was conducted in streptozotocin-induced diabetic hairless rats, and endogenous nitrite and hydroxyproline from homogenized wound tissue were measured along with pharmacokinetic and dermal toxicity in Hanford miniature swine.

RESULTS

Esmolol inhibited the formation of sorbitol by 59% in erythrocytes in comparison to glucose-induced sorbitol levels. AGE generation in bovine serum albumin was reduced at 1 mM esmolol concentrations (2.6 ± 1.7) compared with control (p < 0.05) and similar to that of diclofenac (2.5 ± 1.3). Esmolol at 1 and 10 µM enhanced the migration of fibroblasts, epithelial cells, and keratinocytes compared with control. The nitric oxide levels (day 7) were 44 and 112% higher with Galnobax (14%) than those of the diabetic group (p < 0.05) and the vehicle control group (p < 0.05), respectively. The days 7 and 14 hydroxyproline in the wound was higher by 22 and 44% following Galnobax (14%) compared with the diabetic and vehicle control groups. The wound area exhibited better reduction with Galnobax at 14% up to day 10 follow-up compared with the controls. The pharmacokinetic and dermal toxicity in miniature swine suggested no significant adverse event with Galnobax.

CONCLUSIONS

Topical esmolol hydrochloride is a novel, safe, and effective treatment modality that acts through pleotropic mechanisms to hasten wound healing in diabetes.

Phenytoin-loaded bioactive nanoparticles for the treatment of diabetic pressure ulcers: formulation and in vitro/in vivo evaluation

Drug repurposing offers the chance to explore the full potential of existing drugs while reducing drug development time and costs. For instance, the anticonvulsant drug phenytoin (PHT) has been investigated for its wound healing properties. However, its poor solubility and variability of doses used topically limit its use. Hence, the aim of this study was to improve the properties and wound healing efficacy of PHT for the treatment of diabetic bedsores. PHT was encapsulated, using a modified ionic gelation method, in either positively or negatively charged chitosan-alginate nanoparticles (NPs), which possess previously demonstrated wound healing potential. These NPs were characterized by transmission electron microscopy, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. PHT-loaded NPs were evaluated in vivo for their pressure ulcers' healing potential using diabetic rats. The prepared NPs, especially the positively charged particles, exhibited superior wound healing efficacy compared to PHT suspension, with respect to healing rates, granulation tissue formation, tissue maturation, and collagen content. The positively charged NPs resulted in a 56.54% wound closure at day 7, compared to 37% for PHT suspension. Moreover, skin treated with these NPs showed a mature dermis structure with skin appendages, which were absent in all other groups, in addition to the highest collagen content of 63.65%. In conclusion, the use of a bioactive carrier enhanced the healing properties of PHT and allowed the use of relatively low doses of the drug. Our findings suggest that the prepared NPs offer an effective antibiotic-free delivery system for diabetic wound healing applications.

Topical phenytoin for treating pressure ulcers

BACKGROUND

Pressure ulcers are common in clinical practice and pose a significant health problem worldwide. Apart from causing suffering to patients, they also result in longer hospital stays and increase the cost of health care. A variety of methods are used for treating pressure ulcers, including pressure relief, patient repositioning, biophysical strategies, nutritional supplementation, debridement, topical negative pressure, and local treatments including dressings, ointments and creams such as bacitracin, silver sulphadiazine, neomycin, and phenytoin. Phenytoin is a drug more commonly used in the treatment of epilepsy, but may play an important role in accelerating ulcer healing.

OBJECTIVES

To assess the effects of topical phenytoin on the rate of healing of pressure ulcers of any grade, in any care setting.

SEARCH METHODS

In September 2016, we searched the following electronic databases to identify relevant randomized clinical trials: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid Embase; and EBSCO CINAHL Plus. We handsearched conference proceedings from the European Pressure Ulcer Advisory Panel, European Wound Management Association and the Tissue Viability Society for all available years. We searched the references of the retrieved trials to identify further relevant trials. We also searched clinical trials registries to identify ongoing and unpublished studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) addressing the effects (both benefits and harms) of topical phenytoin on the healing of pressure ulcers of any grade compared with placebo or alternative treatments or no therapy, irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted information on participants, interventions, methods and results and assessed risk of bias using Cochrane methodological procedures. For dichotomous variables, we calculated the risk ratio (RR) with 95% confidence interval (CI). For continuous variables, we calculated the mean difference with 95% CI. We rated the quality of the evidence by using Grading of Recommendations, Assessment, Development and Evaluation approach (GRADE).

MAIN RESULTS

Three small RCTs met our inclusion criteria and included a total of 148 participants. These compared three treatments with topical phenytoin: hydrocolloid dressings, triple antibiotic ointment and simple dressings. In the three RCTs, 79% of participants had grade II ulcers, and 21% of participants had grade I ulcers; no participants had grade III or IV ulcers. Two RCTs had a high risk of bias overall and the other RCT was at unclear risk of bias due to poor reporting. Two RCTs had three intervention arms and the other had two intervention arms.Two studies compared topical phenytoin with hydrocolloid dressing (84 participants analysed). The available data suggest that hydrocolloid dressings may improve ulcer healing compared to topical phenytoin (39.3% ulcers healed for phenytoin versus 71.4% ulcers healed for hydrocolloid dressings (RR 0.55, 95% CI 0.33 to 0.92; 56 participants, 1 study; low quality evidence). We downgraded the evidence twice: once due to serious limitations (high risk of bias) and once due to the small sample size and small number of events. Two studies compared topical phenytoin with simple dressings (81 participants analysed). From the available data, we are uncertain whether topical phenytoin improves ulcer healing compared to simple dressings (39.3% ulcers healed for phenytoin versus 29.6% ulcers healed for the simple dressing (RR 1.33, 95% CI 0.63 to 2.78; 55 participants, 1 study; very low quality evidence). This evidence was downgraded once due to serious limitations (high risk of bias) and twice due to the low number of outcome events and resulting wide CI which included the possibility of both increased healing and reduced healing. We therefore considered it to be insufficient to determine the effect of topical phenytoin on ulcer healing. One study compared topical phenytoin with triple antibiotic ointment, however, none of the outcomes of interest to this review were reported. No adverse drug reactions or interactions were detected in any of the three RCTs. Minimal pain was reported in all groups in one trial that compared topical phenytoin with hydrocolloid dressings and triple antibiotic ointment.

AUTHORS' CONCLUSIONS

This review has considered the available evidence and the result shows that it is uncertain whether topical phenytoin improves ulcer healing for patients with grade I and II pressure ulcers. No adverse events were reported from three small trials and minimal pain was reported in one trial. Therefore, further rigorous, adequately powered RCTs examining the effects of topical phenytoin for treating pressure ulcers, and to report on adverse events, quality of life and costs are necessary.

Re-evaluation of the first phenytoin paste healing effects on oral biopsy ulcers

BACKGROUND

Until now, several formulations of topical phenytoin have been used to promote wound healing.

AIM

This study was aimed at re-evaluating the effects of a newly formulated phenytoin mucoadhesive paste on wound healing after oral biopsy.

SUBJECTS AND METHODS

In a double-blind clinical trial, 35 consecutive patients with oral lichenoid or lichen planus lesions were randomized into two groups. After incisional biopsy, patients applied simple, or 1% phenytoin paste at least three times a day (after each meal), for 4 days. They were evaluated every other day for size of wound closure, severity of pain, and diameter of the inflammatory halo. This study was approved by Medical Ethics committee of Shahid Beheshti University of Medical Sciences, Tehran, Iran. Statistical analysis was performed using Mann-Whitney U test and Ordinal Logistic Regression.

RESULTS

Of 35 patients, 17 (10 [10/17, 59%]) men, 7 (7/17, 41%) women, mean age: 40 (4.11) were in phenytoin group, and 18 (9 [9/9, 50%]) men, 9 (9/9, 50%) women, mean age: 43.1 (5.15) were in placebo group. There were no significant differences between both study groups in terms of age and sex (male/female ratio) (P = 0.76, P = 0.88). As all biopsies were done by means of punch number 8, the incisions were of 10 mm length. After second and third appointments, it was observed that patients in the treatment group showed quicker wound closure and less pain compared to control group significantly (P < 0.05). Although not significant, patients treated with phenytoin paste had smaller inflammatory halo than controls.

CONCLUSION

Applying 1% phenytoin mucoadhesive paste on oral biopsy incisions resulted in accelerated wound healing and decrease in pain.