Use of Rifampicin in the Treatment of Non-Healing Diabetic Foot Ulcer: An Observational Study

Nonhealing diabetic foot ulcer with osteomyelitis is difficult to treat & the majority of cases lead to amputation or foot deformity along with long-term physical and psychological morbidity. Multidrug-resistant polymicrobial infection is the commonest cause. In addition to glycemic control, offloading & debridement of ulcers is necessary. In this observational study, we looked at the outcome of treatment with Rifampicin on such ulcers.

Methods:

Following informed consent, 67 patients (51 male & 16 female) with nonhealing diabetic foot ulcers, not responding to conventional antimicrobial therapy, were included in the study. Mean age 56.67 years (26-74 yrs). 21 had Osteomyelitis (31.34%). 13 had a previous minor amputation. Patients were recruited from March 2018- March 2021 & observed till September 2021. One patient had multiple digital amputations with a residual nonhealing ulcer. Two had Charcot's foot. Three had moderate-severe limb-threatening infections. Data from the cohort included anthropometry, comorbidities, baseline HbA1c, Creatinine & LFT. In addition to glycemic control, patients were provided offloading with posterior slab, regular dressing, debridement, modified footwear. Rifampicin was given for 3 months. In non-healing ulcers, Rifampicin was continued for another 3 months. The total observation period was 6 months. Healing of ulcer & amputation were primary endpoints of the study. The secondary endpoint was a recurrence of the ulcer following healing of the primary ulcer.

Results:

Hypertension was the commonest (82.08%) comorbidity. Others were CKD (20.89%), IHD (17.91%), obesity (14.92%) & dyslipidemia (8.95%). Baseline LFT was normal in all except one patient. Glycemic control was poor in 86.36% with HbA1c > 7.5% (7.8-14.8%). Baseline characteristics of the cohort did not show differences in primary or secondary outcomes based on age, anthropometry parameters, HbA1c (baseline & at the end of study), S. creatinine & comorbidities. Multivariate analysis of risk factors including the same baseline characteristics did not reveal any statistically significant impact. There was 47.4% numerical but statistically nonsignificant increase in the incidence of ulcer healing along with amputation during & after treatment. Use of Rifampicin for 3 months led to complete healing in 58 cases (86.56%). 6 patients (5.97%) needed 6 months of therapy for complete healing of ulcers. Despite healing 10 patients needed further amputation. Six had a recurrence of ulcers, which is statistically insignificant.

Discussion/Conclusion:

Rifampicin used in conjunction with standard polymicrobial therapy in nonhealing diabetic foot ulcers can lead to a significantly improved rate of healing which normally failed to respond to standard polymicrobial therapy. This is independent of baseline anthropometric factors, metabolic parameters including HbA1c & Creatinine. Our findings are consistent with similar studies in the past on the use of Rifampicin in Diabetic Foot Ulcer.