Today sees the launch of Palexia® SR (tapentadol prolonged release) for the oral treatment of adults with severe chronic pain, which can only be adequately managed with opioid analgesics. Palexia® SR is the first in a new class of centrally acting analgesics called MOR-NRI, which has two mechanisms of action in one molecule; both μ-opioid receptor (MOR) agonism and noradrenaline reuptake inhibition (NRI).
In pivotal Phase III trials, Palexia® SR demonstrated comparable analgesic efficacy to oxycodone CR and, importantly, superior gastrointestinal tolerability (constipation, nausea and vomiting) (p<0.001) and significantly fewer discontinuations (43.5%) compared with oxycodone CR (61.7%). Patients were able to stay on Palexia® SR for a median of 118 days compared to 39 days with oxycodone SR, and superior quality of life outcomes were reported by patients administered Palexia® SR, when compared with those in the oxycodone CR arm.
Commenting on the launch of Palexia® SR, Professor Richard Langford, Consultant in Anaesthesia and Pain Medicine, St Bartholomew’s Hospital, London said: “The introduction of a new medication which combines effective pain relief and the potential for reduced side effects is a welcome addition for clinicians and patients alike. Palexia® represents a significant advance which can enable a greater proportion of patients with chronic pain to stay on treatment for as long as is required; consequently improving their quality of life.”
Pre-clinical studies have Palexia® SR to be effective in the treatment of severe chronic nociceptive, neuropathic and mixed pain. These studies suggest that the μ-opioid receptor (MOR) agonism component of Palexia® SR acts primarily on nociceptive pain and the noradrenergic (NRI) component on neuropathic pain. However, both mechanisms of action are thought to contribute to the overall analgesic effect in both types of pain.
As well as offering effective pain relief, the two mechanisms of action result in lower levels of μ-opioid affinity in the pain receptors, thus reducing unpleasant side effects such as nausea, vomiting and constipation, which are commonly experienced by people taking strong opioids such as morphine.
This represents the potential for improved patient quality of life for many people with severe chronic pain who are unable to achieve optimal pain control without experiencing significant side effects, which often lead to treatment non-compliance.
An estimated 20% of adults in the UK live with chronic pain, with back pain alone costing the UK economy £12.3 billion per year; equivalent to almost one fifth of the annual NHS budget. In a recent survey of 450 GPs across the UK, more than a quarter reported that they are ‘not at all’ or ‘not very’ satisfied with currently available treatment options for severe chronic pain, suggesting an unmet treatment need. Furthermore they reported that diagnosis and treatment of severe chronic pain takes up the same amount of their time as type II diabetes and hypertension, a significant proportion of their workload.
Palexia® SR is a Schedule 2 Controlled drug, available on prescription only, and can be used to treat patients with severe chronic pain, such as osteoarthritis, lower back and cancer pain which can be adequately managed only with opioid analgesics such as morphine and oxycodone. The cost of Palexia SR is equivalent to oxycodone CR at usual daily doses.