Provided are formulations comprising therapeutically effective amounts of ambrisentan or a pharmaceutically acceptable salt thereof and tadalafil or a pharmaceutically acceptable salt thereof and methods of treating and/or preventing pulmonary hypertension by administration of the formulations.本發明提供包括治療有效量之安倍生坦(ambrisentan)或其醫藥上可接受之鹽及他達拉非(tadalafil)或其醫藥上可接受之鹽之調配物及藉由投與該等調配物來治療及/或預防肺高血壓之方法。