By Pat Anson, Editor
At a time when hundreds – perhaps thousands – of Americans and Canadians are dying every month from overdoses of illicit fentanyl mixed with heroin or turned into counterfeit painkillers, it’s easy to lose sight of the fact that prescription fentanyl is an important and useful analgesic.
We were reminded of that today by the World Health Organization (WHO), which added fentanyl skin patches and methadone to its list of essential medicines for treating cancer pain. WHO’s Essential Medicine List is not widely followed in developed countries – where prescription drugs are widely available – but it is used in many third world countries to guide decision making and increase access to medicines that are often in short supply.
"Safe and effective medicines are an essential part of any health system," said Dr. Marie-Paule Kieny, WHO Assistant Director-General for Health Systems and Innovation. "Making sure all people can access the medicines they need, when and where they need them, is vital to countries’ progress towards universal health coverage."
Fentanyl patches and methadone are two of the 30 drugs being added to the Essential Medicine List, raising the total to 433 medicines considered vital in addressing public health needs. WHO also added drugs for treating HIV, hepatitis C, tuberculosis and leukemia; and gave new advice about the use of antibiotics.
While illicit, black market fentanyl has become a deadly scourge across the U.S. and Canada, prescription fentanyl is legally available in patches, lozenges and sprays to treat severe pain.
WHO’s inclusion of fentanyl patches and methadone on the essential list is limited to the treatment of cancer pain. An expert panel that reviewed the medicines noted “there is a need for additional opioid treatment options” for cancer pain. About a third of cancer patients worldwide are undertreated for pain, and patients living in low or middle income countries often have limited access to opioid painkillers.
Other opioids already on the essential list (for treating pain and palliative care) are codeine, morphine, hydromorphone and oxycodone . Aspirin, ibuprofen and paracetamol (acetaminophen) are on it too, although the latter is “not recommended for anti-inflammatory use due to lack of proven benefit.”
It’s also worth noting the medications that did not make the updated WHO list. Tramadol was not approved as a treatment for cancer pain, while gabapentin (Neurontin) was rejected as a treatment for neuropathic pain.
WHO’s expert panel gave a scathing review of the application made by the International Association for the Study of Pain and the International Association of Hospice and Palliative Care for the inclusion of gabapentin; noting there were many cases of bias and data manipulation in the clinical studies used to support it. Also noted was the $430 million fine paid by Pfizer in 2004 to settle civil and criminal charges for a “marketing scheme” to promote Neurontin for unapproved uses.
“The Committee acknowledged the serious issues on publication and outcome reporting bias as important ones,” the panel said. “The Expert Committee considered the uncertainty in efficacy estimates as a result of publication and outcome reporting biases in the currently available evidence for gabapentin. The Committee did not recommend inclusion of gabapentin on the EML (Essential Medicine List) for neuropathic pain on the basis of its uncertain benefits.”
While gabapentin is approved for neuropathic pain in the European Union and Australia, it is only approved for epilepsy and neuropathic pain caused by shingles in the U.S. Despite that limitation, gabapentin is widely prescribed “off label” to treat depression, anxiety, migraine, fibromyalgia and other chronic pain conditions. About 64 million prescriptions were written in the U.S. for gabapentin in 2016, a 49% increase since 2011.