The study, “Safety and effectiveness of tadalafil in pediatric patients with pulmonary arterial hypertension: a sub-group analysis based on Japan post-marketing surveillance,” was published in the journal Current Medical Research and Opinion.
Adult PAH patients have several therapies available for their disease that differ in terms of active mechanisms. Adcirca and Viagra (sildenafil), for example, belong to the class of phosphodiesterase type 5 inhibitors (PDE5 inhibitor) and are the only two medicines of this category approved for the treatment of PAH. These treatments help control blood flow to the pulmonary arteries, causing the blood vessels to relax.
A small number of studies have shown that Adcirca improved clinical symptoms and was well-tolerated in children and adolescents with PAH, although the dosage for pediatric patients is not yet approved.
“However, since the number of pediatric patients included in these studies was quite small, little is still known concerning the use of tadalafil in pediatric patients with PAH,” researchers wrote.
To evaluate the long-term safety and effectiveness of Adcirca in real-world clinical practice with pediatric patients with PAH, researchers collected data from 391 patients treated with Adcirca at several medical institutions throughout Japan.
Patients received Adcirca at the physician’s discretion — doses varied from 10 mg to 40 mg — and were followed for up to two years.
Results showed that 16.6% of patients experienced an adverse drug reaction. The most common reactions were headaches, abnormal hepatic function, decreased platelet count, and epistaxis (bleeding from the nose). Eleven patients experienced serious adverse drug reactions, and three patients died secondary to the reactions.
Effectiveness was determined based on changes in the World Health Organization (WHO) functional class of PAH, cardiac catheterization (pulmonary arterial pressure), and echocardiography (tricuspid regurgitation pressure gradient, TRPG).
Three months after starting treatment, 8.6% of patients showed improvements in their WHO functional class. This percentage increased to 16.5%, 19.7%, and 16.3%, at one year, two years, and at the study’s end, respectively.
Additionally, pulmonary arterial pressure and TRPG showed a statistically significant reduction at the time of the last observation.
Overall, the results suggested that Adcirca is both safe and effective when tested in a real-world pediatric population. The study’s limitations include being conducted “in a single cohort, the patients were not randomized by age or treatment group, and there was no control or comparator group.”