<P> The WHO guidelines recommend prompt oral administration of drugs ("by the mouth") when pain occurs, starting, if the patient is not in severe pain, with non-opioid drugs such as paracetamol (acetaminophen) or aspirin, with or without "adjuvants" such as non-steroidal anti-inflammatory drugs (NSAIDs) including COX - 2 inhibitors . Then, if complete pain relief is not achieved or disease progression necessitates more aggressive treatment, a weak opioid such as codeine, dihydrocodeine or tramadol is added to the existing non-opioid regime . If this is or becomes insufficient, a weak opioid is replaced by a strong opioid, such as morphine, diamorphine, fentanyl, buprenorphine, oxymorphone, oxycodone, or hydromorphone, while continuing the non-opioid therapy, escalating opioid dose until the patient is pain free or at the maximum possible relief without intolerable side effects . If the initial presentation is severe pain, this stepping process should be skipped and a strong opioid should be started immediately in combination with a non-opioid analgesic . </P> <P> The guideline directs that medications should be given at regular intervals ("by the clock") so that continuous pain relief occurs, and ("by the individual") dosing by actual relief of pain rather than fixed dosing guidelines . It recognizes that breakthrough pain may occur and directs immediate rescue doses be provided . </P> <Table> WHO Pain Ladder <Tr> <Th> Step 1 . </Th> <Td> Mild pain: </Td> <Td> </Td> <Td> </Td> <Td> Non-opioid </Td> <Td> + </Td> <Td> Optional adjuvant </Td> <Td> If pain persists or increases, go to step 2 . </Td> </Tr> <Tr> <Th> Step 2 . </Th> <Td> Moderate pain: </Td> <Td> Weak opioid </Td> <Td> + </Td> <Td> Non-opioid </Td> <Td> + </Td> <Td> Optional adjuvant </Td> <Td> If pain persists or increases, go to step 3 . </Td> </Tr> <Tr> <Th> Step 3 . </Th> <Td> Severe pain: </Td> <Td> Strong opioid </Td> <Td> + </Td> <Td> Non-opioid </Td> <Td> + </Td> <Td> Optional adjuvant </Td> <Td> Freedom from pain . </Td> </Tr> </Table> <Tr> <Th> Step 1 . </Th> <Td> Mild pain: </Td> <Td> </Td> <Td> </Td> <Td> Non-opioid </Td> <Td> + </Td> <Td> Optional adjuvant </Td> <Td> If pain persists or increases, go to step 2 . </Td> </Tr>

How many steps in world health organization pain ladder