The effect of tadalafil on reepithelialization and scarring of partial thickness porcine burns

Burn conversion from second to third degree is common leading to delayed healing and scarring. We hypothesized that tadalafil, a phosphodiesterase 5 inhibitor (PDE5I) that results in vasodilation, would reduce burn conversion leading to faster reepithelialization and less scarring of partial thickness porcine burns. We conducted a prospective, randomized, controlled, animal experiment using six female pigs (25–30 kg). We created 20 standardized partial thickness burns on each of the animals with an aluminum bar preheated to 80 °C and applied for 20 seconds to the pigs' dorsum. Three animals each were randomized to oral tadalafil 2.5 mg or control vehicle once daily for 1 week. Main outcomes were time to reepithelialization and depth of scarring at 28 days. A sample of 60 burns in each treatment group had 80% power to detect a 2-day difference in time to reepithelialization. Mean (95% CI) time to reepithelialization in burns treated with tadalafil and control were 14.9 (14.1–15.7) vs. 19.7 (18.2–21.3) days, respectively; mean difference 4.8 (3.1–6.6) days. After controlling for pig and within pig differences, mean time to reepithelialization was 6.5 (3.7–9.3) days shorter in burns treated with tadalafil compared with controls. Mean (95% CI) scar depth in burns treated with tadalafil and control were 2.7 (2.3–3.1) vs. 3.7 (3.1–4.2) mm. respectively, mean difference 1 (0.3–1.7) mm. After controlling for pig and within pig differences, scar depth in tadalafil-treated burns was 1.5 (0.7–2.3) mm lower compared with controls. We conclude that once daily oral tadalafil shortened time to reepithelialization and reduced scarring in a partial thickness porcine burns model.