A factorial, randomized trial of pentoxifylline or placebo, four-layer or single-layer compression, and knitted viscose or hydrocolloid dressings for venous ulcers

Objectives: We evaluated the effectiveness of pentoxifylline, knitted viscose or hydrocolloid dressings, and single-layer or four-layer bandaging for venous ulceration. Method: A factorial randomized controlled trial with 24-week follow-up was conducted in leg ulcer clinics in Scotland with blinded allocation to pentoxifylline (1200 mg) or placebo, knitted viscose or hydrocolloid dressings, and single-layer or four-layer bandages. The study enrolled 245 adults with venous ulcers. The main outcome measure was time to complete healing. Secondary outcomes included proportions healed, withdrawals, and adverse events. Analysis was by intention to treat. Results: There was no evidence of interaction between the drug, bandages, and dressings. Pentoxifylline was associated with nonsignificant increased ulcer healing (62% vs 53%; P = .21). Four-layer bandages were associated with significantly higher healing rates (67% vs 49%; P = .009). There was no difference in healing between knitted viscose and hydrocolloid dressings (58% and 57%; P = .88). Cox regression models increased the significance of the pentoxifylline effect (relative risk of healing, 1.4; 95% confidence interval, 1.0 to 2.0). Conclusions: Pentoxifylline increased the proportion healing compared with placebo to the same extent as shown in recent systematic reviews, although this finding was only statistically significant when a secondary adjusted analysis was conducted. Four-layer bandaging produced higher healing rates than single-layer bandaging. There was no difference in time to healing between knitted viscose and hydrocolloid dressings.