New opioid side effects and implications for long-term therapy

Opioids are the foundation for the treatment of acute pain and cancer pain. Their popularity in the chronic pain setting has waxed and waned over the years but there has been a recent resurgence in their use. Opioid induced side effects such as nausea, constipation, tolerance and addiction are well known, but studies have shown that a range of subtle yet significant complications have emerged which have the potential to increase the morbidity of patients who are on long-term opioid therapy. They include hypogonadism, osteoporosis, immune suppression, cognitive impairment and hyperalgesia. Therefore it is important for clinicians to be aware of these side effects and remain vigilant for them. Patients receiving chronic opioid therapy may benefit from a strategy to minimise the occurrence of these side effects. (C) 2010 Elsevier Ltd. All rights reserved.