Chronic pain affects approximately 1 in 5 people in Europe, and around half of sufferers receive inadequate
pain management. The most common location is the lower back. Pharmacological treatment of this condition is challenging because of the range of causative mechanisms and the difficulty of balancing
analgesic efficacy and tolerability. An international panel of clinical
pain specialists met in September, 2009, to discuss the treatment of chronic
low back pain, and to review preclinical and clinical data relating to the new
analgesic,
tapentadol. A lack of consensus exists on the best treatment for
low back pain. The range of regularly prescribed pharmacological agents extends from nonopioids (
paracetamol,
NSAIDs, and
COX-2 inhibitors) to
opioids,
antidepressants and
anticonvulsants.
Pain relief may be compromised, however, by an undetected neuropathic component or intolerable side effects. Treatment is potentially life-long and effective
analgesics are urgently needed, with demonstrable long-term safety. Combining separate agents with different mechanisms of action could overcome the limitations of present pharmacological
therapy, but clinical evidence for this approach is currently lacking.
Tapentadol combines μ-
opioid agonism with
noradrenaline reuptake inhibition in a single molecule. There is strong evidence of synergistic antinociception between these two mechanisms of action. In preclinical and clinical testing,
tapentadol has shown efficacy against both nociceptive and
neuropathic pain. Preclinical data indicate that
tapentadol's μ-
opioid agonism makes a greater contribution to
analgesia in
acute pain, while
noradrenaline reuptake inhibition makes a greater contribution in chronic
neuropathic pain models.
Tapentadol also produces fewer adverse events than
oxycodone at equianalgesic doses, and thus may have a 'μ-sparing effect'. Current evidence indicates that
tapentadol's efficacy/tolerability ratio may be better than those of classical
opioids. However, further research is needed to establish its role in
pain management.