Introduction: Pulmonary arterial hypertension in children has consequences such as right ventricular failure and even death. Recently, the use of phosphodiesterase 5 inhibitors has been taken into account in the treatment of pulmonary hypertension, among which tadalafil is more acceptable by parents and patients due to its single dose per day compared to sildenafil which should be taken 4 times a day. Therefore, this study aimed to investigate the effect of tadalafil on reducing pulmonary artery pressure in children and adolescents aged 5 months to 15 years old.

Methods: This before and after type study entailed 20 patients of 5-month to 15-year with pulmonary arterial hypertension who had outpatient visits in Yazd Khatam-L-Anbiya clinic during 2013-2014. The participants were diagnosed by echocardiography, considering that they had not ever received any pulmonary arterial pressure lowering medicine up to now, whose congenital heart disease were inoperable. They were then treated using a single dose of oral tadalafil for 6 months. The collected data were analyzed using SPSS software via t-test and Chi-square tests.

Results: Mean of pulmonary arterial pressure before and six months after taking tadalafil were 52.30 ± 7.948 mmHg and 33/55 ± 10/34 mmHg, respectively, which on average it was decreased by 18.75 mmHg(pv<0.0001). The mean of arterial oxygen saturation was reported %82.45 ± 7.14 and %86.25 ± 6.496 before and after taking tadalafil, respectively which was increased by 3.9% (pv<0.0001). The severity of tricuspid failure was reduced from moderate to mild level. No serious complication was observed leading to drug discontinuation in the patients’ follow-ups.

Conclusion: The study findings revealed that tadalafil drug is effective on the treatment of pulmonary arterial hypertension within children and adolescents. Moreover, it can be used instead of sildenafil, due to its single dose per day.