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.
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.
Up to 90 percent of cancer patients, immediay preceding death, use such adjuvants. Not all pain yields compley to classic analgesics, and drugs that are not traditionally considered analgesics, but which reduce pain in some cases, such as steroids or bisphosphonates, may be employed concurrently with analgesics at any stage.
Ann Oncol. 1994 Feb;5(2):141-6. Oral tramadol, a mu-opioid agonist and monoamine reuptake-blocker, and morphine for strong cancer-related pain. Wilder-Smith CH(1), Schimke J, Osterwalder B, Senn HJ. Author information: (1)Department of Medicine, Inselspital, University of Berne, Switzerland. BACKGROUND: Opioid.
This initial study compared the analgesic and toxic effects of tramadol and morphine in patients with strong cancer pain. Tramadol has both opioid and monoaminergic agonist actions. Opioid and spinal monoaminergic agonists have distinct analgesic properties, which may potentiate each other.
The mean daily doses on day 4 were 101 +/- 58 mg of morphine and 375 +/- 135 mg of tramadol, indicating a relative potency of 4:1 with oral dosing.