A consensus for non-cancer pain management
With Dr Kok Yuen Ho | 22 Dec 2015 | Print
An interview with Dr Kok Yuen Ho, Pain Medicine Specialist, Raffles Pain Management Centre, Raffles Hospital, Singapore; President of the Pain Association of Singapore; Organizing Chair of the 5th ASEAPS Conference.
“Opioids are underused in South-east Asia, such that there is a huge gap in patient access to opioids compared with the US, for example,” said Dr Kok Yuen Ho, a pain medicine specialist and President of the Pain Association of Singapore. “This may relate to physician unwillingness to write prescriptions, as well as patient fears regarding opioids.”
To tackle the problem, a task force of leading pain experts in Singapore has developed a new consensus statement, the 2013 ‘Evidence-Based Guidelines on the Use of Opioids in Chronic Non-Cancer Pain’.1 PainFocus™ caught up with Dr Ho, who is lead author of the guidelines. In an enlightening interview, Dr Ho described the place of opioids in the management of chronic pain, and discussed his hopes for the future of this field.
Chronic non-cancer pain poses a substantial, and increasing, health burden
Chronic pain is defined as any pain that persists beyond the normal tissue healing time of about 3 months.2 “Data are now showing that chronic pain is not a symptom, it is a disease. It is linked to epigenetic changes in the brain,” explained Dr Ho.
Prevalence data from Hong Kong and Singapore show that about 10% of adults and up to one in five of the elderly experience chronic pain.3,4 Low back pain may affect up to one third of the population at any given time,5 and almost two-thirds of people experience neck pain during their lifetime.6 These figures are likely to increase: “As the population ages, we will see more and more patients with chronic pain,” Dr Ho said. Singapore expects to have twice as many elderly people in 2025 as it does today.7,8
Opioids have a role in the management of chronic pain
The ‘Evidence-Based Guidelines on the Use of Opioids in Chronic Non-Cancer Pain’ note that there is evidence to support the use of opioids in well-selected patients with chronic non-cancer pain (CNCP).1 “Opioids have been shown to be effective for short-term pain relief,” Dr Ho said. “The guidelines use a disease-specific approach to define which conditions are responsive to opioid therapy.” They also provide an algorithm for appropriate initiation and maintenance of patients on these treatments, and aim to help improve access to these opioid therapies, while reducing opioid abuse and diversion. Although the current focus of the guidelines is on CNCP, the long-term vision is to expand across the range of pain pathologies.
The best practice use of opioids for specific CNCP conditions is given in the Table.1 Opioids are not recommended for orofacial pain conditions, or fibromyalgia (except tramadol).
Table. Recommendations from the Singapore guidelines on opioid usage in chronic non-cancer pain1
|Condition||Quote from the guidelines|
|Low back pain||Opioids may be used for up to 12 months in chronic non-specific low back pain, but they (including tramadol) should be used as part of a multimodal treatment regimen.|
|Neck pain||Long-term use does not appear appropriate, but opioids can be used as an alternative therapy if other analgesics are ineffective.|
|Musculoskeletal pain||Opioids can provide mild-to-moderate pain relief and improved function when used as an alternative therapy if other analgesic agents are ineffective.|
|Headache||For episodic headaches, opioids can be used as rescue therapy only if first-line therapies are ineffective or contraindicated. Daily opioids may help a minority of patients with chronic headache and frequent and disabling symptoms that fail to respond to other therapies.|
|Chronic pelvic pain||Opioids can be considered as part of multidisciplinary care and rehabilitation.|
|Post-herpetic neuralgia||Opioids can be considered as an add-on therapy to further improve symptoms in patients who are partial responders to conventional medications, and as alternative agents after failure of first-line treatments or development of intolerable side effects.|
|Diabetic peripheral neuropathic pain||Opioids appear efficacious as monotherapy or as an add-on therapy in combination with tricyclic antidepressants or anticonvulsants, or can be considered after failure of first-line treatments or development of intolerable side effects.|
|Peripheral vascular disease||Monotherapy with oral opioids may be used as an alternative to epidural infusions.|
Take a stepwise approach to prescribing opioids
The guidelines also provide a stepwise approach for selecting appropriate patients: “an algorithm that clinicians can follow to safely prescribe opioids,” Dr Ho said (Figure).
Figure. Stepwise approach for prescribing opioid therapy in non-cancer pain1
During the initial evaluation, clinicians should assess the nature and intensity of the pain, its effect on physical and psychosocial functioning, and current and previous treatments. The risk of substance abuse can be assessed using several available screening tools (eg, the Diagnosis, Intractability, Risk, Efficacy [DIRE] Instrument9). Patients identified to be at risk should be referred to a specialist trained in addiction or pain medicine for further assessment.
In appropriately selected patients with CNCP, opioid therapy can be an important element of multimodal management, which may also include cognitive behavioral therapy, rehabilitation programs, and other medications. Before initiating opioid therapy, clinicians should obtain informed consent, ideally in the form of an opioid therapy agreement with the patient. An opioid therapy agreement covers compliance with addiction monitoring, ongoing communication, and safety precautions for obtaining and handling opioids. “This will help to protect both the prescriber and the patient,” said Dr Ho.
The guidelines use a disease-specific approach to define which conditions are responsive to opioid therapy
Realistic treatment goals should also be discussed with the patient. “Typically we are looking for pain reduction rather than resolution, so patients should not expect 100% pain relief,” Dr Ho noted. Other realistic goals include functional improvements, enhanced quality of life, and the ability to return to work.
The choice of opioid, initial dose and titration should be tailored to the patient’s needs, based on identifying the minimal effective dose that controls pain and causes minimal adverse effects. An initial assessment of effectiveness may be performed during a short-term trial (4-8 weeks), before proceeding to longer-term opioid use.
Regular adherence monitoring is recommended beyond the initial trial period, to address the risks of polypharmacy, drug interactions, aberrant drug-taking behavior and opioid addiction. Aberrant behaviors include doctor shopping, obtaining opioids illegally, frequently losing opioid doses, noncompliance with treatment, and concurrent misuse of alcohol and other drugs. High-risk patients should be monitored on a weekly (or more frequent) basis, with periodic urine drug screening and pill counts. Low-risk patients may only need to visit the clinician every 2 to 3 months. For all patients, the monitoring and assessment process should be based on the “4 A’s”10:
- Analgesia: is adequate pain relief being achieved?
- Activities of daily living: is the patient able to function adequately?
- Adverse events: is the patient experiencing side effects?
- Aberrant drug-taking behavior: is there any suspicion of aberrant behavior or addiction?
In patients who pass the 4 A’s and meet the other criteria for success defined at the beginning of therapy, opioids can often be continued successfully over the longer term. For patients who achieve poor outcomes, opioids should be discontinued after appropriate dose tapering.
Spreading the word: Singapore and beyond
The guidelines align well with several ongoing initiatives that Dr Ho is involved with at ASEAPS. For example, ASEAPS recently co-hosted a ‘Pain Management Camp’ for aspiring pain specialists from across the region. “The objective was to develop new pain leaders, so that they will become educators and advocators for best practice in their own countries,” Dr Ho said.
As the population ages, we will see more and more patients with chronic pain
The next step is to encourage uptake of the guidelines within the wider medical community, including general practitioners. “We want to start with pain physicians, and then bring in other key specialties. We also hope that this platform will help us improve public awareness and reach out to policy makers,” Dr Ho explained.
He also has other ambitious goals for the future. “We would like to grow the guidelines to involve the other countries within ASEAPS, and to expand beyond non-cancer pain. We would also like to have pain medicine better recognized as a specialty in its own right, and to grow ASEAPS by bringing in other countries in the region.”
1. Ho KY, Chua NH, George JM, et al. Evidence-based guidelines on the use of opioids in chronic non-cancer pain – a consensus statement by the Pain Association of Singapore Task Force. Ann Acad Med Singapore 2013;42:138-152.
2. Chou R. 2009 Clinical Guidelines from the American Pain Society and the American Academy of Pain Medicine on the use of chronic opioid therapy in chronic noncancer pain: what are the key messages for clinical practice? Pol Arch Med Wewn 2009;119:469-477.
3. Ng KF, Tsui SL, Chan WS. Prevalence of common chronic pain in Hong Kong adults. Clin J Pain 2002;18:275-281.
4. Yeo SN, Tay KH. Pain prevalence in Singapore. Ann Acad Med Singapore 2009;38:937-942.
5. Walker BF. The prevalence of low back pain: a systematic review of the literature from 1966 to 1998. J Spinal Disord 2000;13:205-217.
6. Chiu TT, Leung AS. Neck pain in Hong Kong: a telephone survey on prevalence, consequences, and risk groups. Spine 2006;31:E540-E544.
7. Singapore Department of Statistics. Population Trends 2011. Available at: www.singstat.gov.sg/stats/themes/people/popinbrief2011.pdf. Accessed 7 March 2013.
8. United Nations. World Population Ageing 1950-2050. Available at: www.un.org/esa/population/publications/worldageing19502050/. Accessed 7 March 2013.
9. Belgrade MJ, Schamber CD, Lindgren BR. The DIRE score: predicting outcomes of opioid prescribing for chronic pain. J Pain 2006;7:671-681.
10. Passik SD, Kirsh KL, Whitcomb L, et al. A new tool to assess and document pain outcomes in chronic pain patients receiving opioid therapy. Clin Ther 2004;26:552-561.
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