Buprenorphine was not used widely in clinical practice over many years, mainly due to
analgesic potency and clinical safety concerns based on misinterpreted animal data. Contrary to previous concerns, however, no
analgesic ceiling effect and no antagonism of combined pure
mu-opioid receptor agonists is seen within the therapeutic dose range. In recent studies,
buprenorphine could be effectively and safely combined with full mu-agonists, and switching between
buprenorphine and another
opioid provided comparable
pain relief based on equianalgesic doses. Moreover,
buprenorphine exerts an antihyperalgesic effect, which is due -- at least in part -- to antagonistic activity at
kappa-opioid receptors.
Buprenorphine pharmacokinetics are not altered by advanced age or renal dysfunction. In addition, the risk of
respiratory depression is lower than with other
opioids including
morphine,
hydromorphone,
methadone and
fentanyl. Unlike
morphine and
fentanyl, there is no immunosuppressive activity with
buprenorphine at therapeutic
analgesic doses. Transdermal
buprenorphine has significantly improved the clinical use of the
drug, providing continuous
buprenorphine release for up to 96 h. In clinical trials, patients receiving transdermal
buprenorphine experienced significantly greater
pain relief, better sleep, and a reduced need for rescue
therapy, compared to placebo. Large-scale post-marketing studies have confirmed the effectiveness of transdermal
buprenorphine in treating moderate-to-severe
cancer and non-
cancer pain including neuropathic syndromes. Finally, the comparably low incidence of CNS adverse events and
constipation, and the possibility of use in severe renal dysfunction without a need for dose adjustment make
buprenorphine well suited for
chronic pain management in at-risk patients, such as diabetics, elderly or renally impaired individuals including those requiring haemodialysis.