**2. Pharmacological treatment of PDA in preterm infants**

Pharmacological treatments induce ductal constriction with good effectiveness overall, whether using non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen in different routes of administration [25–29]. However, complete ductal closure or shunt elimination cannot be guaranteed even when combining these agents together; this is in addition to potential adverse side effects [30–32].
