New fast-acting drugs have been developed to combat an intense pain associated with cancer, writes MICHELLE McDONAGH
UP TO HALF of cancer patients who are on opioid medication to relieve chronic pain experience another type of pain called Breakthrough Cancer Pain (BTcP), which periodically breaks through the medication.
BTcP is an acute pain which comes on very quickly, is intense and lasts for a short period. Although it’s been more than 20 years since it was first noted that BTcP significantly affected cancer patients’ quality of life, it is only in recent years that rapid-onset opioids have been developed to adequately treat it.
During her illness, the famous cervical cancer patient Jade Goody was often seen sucking on a lozenge. This lozenge is designed to deliver the painkiller Fentanyl quickly into the patient’s system to alleviate BTcP.
The physician who put BTcP on the map was Dr Russell Portenoy, head of the Pain Medicine and Palliative Care Department at Beth Israel Medical Center in New York. He will be visiting Dublin this week to speak at a meeting of healthcare professionals on the topic of breakthrough cancer pain.
Portenoy was the first medical professional in the world to evaluate this condition scientifically, in 1990.“We now know that patients who have breakthrough pains actually have a more severe pain syndrome,” he says.
These transitory episodes of pain are more intense than the underlying pain, lead to increased psychological distress in patients and a reduced quality of life. The cost of caring for these patients is higher than for patients without BTcP,” he says.
Over the past two decades, the pharmaceutical industry and its advisers, including Portenoy, have been trying to identify treatments that might work more efficiently in dealing with BTcP.
The standard treatment for breakthrough pain for many years was the use of short-acting oral opioids such as immediate release morphine, but there was a mismatch between the drug and the usual course of this pain – the patient often experienced an episode of severe pain which had passed by the time the opioid was absorbed and started to take effect.
Since the development of the rapid-onset opioid concept, however, Fentanyl can now be delivered to patients much faster through the transmucosal membranes, offering much more effective pain relief. There are now a number of different rapid-onset opioid products on the market including lozenges, effervescent tablets and nasal sprays – with a number more in development.
“I think most experienced clinicians believe that the advent of the new rapid-onset opioids represents a significant medical advance,” says Dr Portenoy. “For those patients who don’t respond well to the short-acting oral opioids, and those who present having very rapid onset pains, these medications could potentially provide analgesia that wouldn’t otherwise be possible.
“The future – I hope – will bring more studies of a comparative nature, so that we’ll be able to make more reasoned judgments about what segments of the cancer-pain population could truly benefit from these drugs.”
Despite these welcome advances in the development of new analgesic drugs for BTcP, the treatment of cancer pain in the US and Europe is still far from optimal, according to Portenoy.
He says the reasons for this include inadequate assessment of pain among clinicians and a lack of expertise in optimising pharmacotherapy, as well under-reporting of pain by patients who fear addiction and side effects.
On top of this, he points out, there are significant system-related problems that may impede the process of cancer pain management. These vary from country to country.
The European Pain in Cancer survey carried out in 2009 found that the treatment of cancer pain across Europe and Israel was sub-optimal.
Of more than 5,000 cancer patients studied, 66 per cent suffered moderate to severe pain at least monthly. Of those prescribed analgesics, 63 per cent experienced breakthrough pain. In all, 69 per cent reported pain-related difficulties with everyday activities.
