Pain ladder
"Pain ladder", or analgesic ladder, was created by the World Health Organization (WHO) as a guideline for the use of drugs in the management of pain. Originally published in 1986 for the management of cancer pain, it is now widely used by medical professionals for the management of all types of pain.
The general principle is to start with first step drugs, and then to climb the ladder if pain is still present. The medications range from common, over-the-counter drugs at the lowest rung, to strong opioids.