ABSTRACT
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.