在新生儿和患有肺动脉高压血管疾病的儿童中进行的药物试验提出了独特但并非不可克服的挑战。童年的定义是成长和发展。两者都可能影响疾病和药物试验的结果。正在发育的肺血管床和气道可能会发生发育不良、适应不良、生长阻滞或失调，从而影响疾病的表型。药物治疗受肾和肝血流发育变化以及代谢系统(如细胞色素P450)的影响。药物对儿童的影响可能不同于成人，具有不同的清除、治疗水平和毒性。毒性可能直到孩子身体、内分泌和神经发育成熟时才表现出来。如果卵子或精子的发育受到影响，其副作用可能会在下一代显现出来。安全、适合年龄的药片和液体配方是任何儿科药物试验的先决条件，但往往被忽视。在设计临床试验时，需要精确的疾病表型和基因分型，以确保适当和准确的纳入和排除标准。 We need to explore physiologically based pharmacokinetic modeling and simulations together with statistical techniques to reduce sample size requirements. Clinical endpoints such as exercise capacity, using traditional classifications and testing cannot be applied routinely to children. Many lack the necessary neurodevelopmental skills and equipment may not be appropriate for use in children. Selection of endpoints appropriate to encompass the developmental spectrum from neonate to adolescent is particularly challenging. One possible solution is the development of composite outcome scores that include age and a developmentally specific functional classification, growth and development scores, exercise data, biomarkers and hemodynamics with repeated evaluation throughout the period of growth and development. In addition, although potentially costly, we recommend long-term continuation of blinded dose ranging after completion of the short-term, double-blind, placebo-controlled trial for side-effect surveillance, which should include neurodevelopmental and peripubertal monitoring. The search for robust evidence to guide safe therapy of children and neonates with pulmonary hypertensive vascular disease is a crucial and necessary goal.