WHO level scheme

The World Health Organization (WHO) has developed a four-tiered scheme for pain therapy that was originally developed for tumor patients, but which is also the basis for the treatment of other types of pain:

Stage 1: In the first stage of the treatment of not too severe pain, so-called non-opioid analgesics are used, i.e. analgesics that do not belong to the class of opioids. These include paracetamol, metamizole and diclofenac. These analgesics are combined with so-called adjuvants.
These are drugs that do not themselves relieve the pain, but are intended to reduce the side effects of the painkillers. These include proton pump inhibitors to protect the stomach, laxatives to relax the bowel and prevent constipation and antiemetics to reduce nausea and vomiting. Furthermore, a combination with coanalgesics can be used.

Coanalgesics themselves do not have any pain-reducing effect either, but they can increase the effect of the analgesics. Some antidepressants and antiepileptic drugs belong to this group.
Stage 2: For more severe pain, according to stage 2 of the WHO stage scheme, non-opioids of stage 1 are combined with low-potency opioids. Low-potency opioids already belong to the class of opioids, but only have a medium potency.
These include tramadol, tilidine/naloxone and codeine. Also at level 2, adjuvants and coanalgesics are used in addition to painkillers.
Stage 3: For very severe pain, stage 3 of the WHO stage scheme comes into play. Instead of low-potency opiodia, high-potency opiodes are combined with the non-opioid analgesics of stage 1.
High-potency opioids are characterized by a very strong analgesic effect. This class includesB. Fentanyl, buprenorphine, morphine, oxycodone and hydromorphone.

The combination with coanalgesics and adjuvants is also obligatory at this level.
Level 4: Severe pain often requires invasive therapeutic methods. Here, the painkillers are injected directly to the desired site of action using specific procedures. Stage 4 therefore includes epidural anaesthesia (PDA) and spinal anaesthesia (SPA), in which the analgesic is applied close to the spinal cord via a cannula, as well as peripheral local anaesthesia, in which nerves can be blocked directly via a catheter. In addition, procedures such as spinal cord stimulation (SCS) are also included in level 4.