Non-opioid analgesics, according to the WHO pain ladder, include various substance classes with different mechanisms of action. In addition to the classical NSAIDs and selective COX-2 inhibitors, substances such as paracetamol; and metamizole are also members of this group. Metamizole is prohibited in several European countries due to potential serious side effects.
Non-opioid analgesics can be classified due to their chemical characteristics as acid (NSAIDs = non-steroidal anti-inflammatory drugs such as ASA, ibuprofen, diclofenac, naproxen) and non-acid (paracetamol, metamizole).
The common mechanism of action of these substances is their effect on prostaglandin synthesis.