RESUMEN
One essential component of the neurovascular system is known as the blood-brain barrier (BBB). This highly effective biological barrier plays a pivotal role in regulating the brain's internal microenvironment and carefully controlling the passage of various chemicals into and out of the brain. Notably, it serves as a safeguard for the brain, particularly when it comes to the selective transportation of drugs like opioids and non-steroidal anti-inflammatory medications (NSAIDs), which are commonly used in the management of chronic pain. It's important to note that during the development of chronic pain, the activation of microglia and astrocytes can potentially disrupt or damage the integrity of the BBB. In this comprehensive review, we aim to delve into the intricate interplay between the blood-brain barrier and the transportation of pain-relieving drugs, shedding light on the challenges and mechanisms involved in this process.