There is increasing evidence for a lack of long term benefit from conventional “pure mu” opioids when used for chronic non-cancer pain [1-3].
Additionally, there is increasing concern with these conventional opioids either being misused by the individual for whom they are prescribed, or being diverted into an illicit drug supply network [4, 5]. It is estimated that per 100,000 heads of population, Australia has half the conventional opioid death rate of the United States when illicit Fentanyl deaths are excluded [6].
What then is the appropriate response to reviewing a patient who has been prescribed a moderate to high dose of conventional pure mu opioids for a number of years and is still reporting significant pain, typically on a numerical rating scale of 5/10 to 10/10? Certainly, the conclusion one can draw is that the opioid is not or is no longer providing the analgesia it once did and that the patient may well be taking the opioid in order to prevent opioid withdrawal, rather than for any direct therapeutic benefit.
It is therefore appropriate to consider a trial of deprescribing of the conventional or pure mu opioid and assess what the clinical response is from such a deprescribing trial. In that process, it is important to communicate with the patient and indicate that, in all likelihood, their pain is not likely to worsen as the conventional opioid is reduced [7, 8]. If carried out in stages over a number of weeks, it can be done is a smooth manner with minimal opioid withdrawal symptoms by stepping down sequentially each week over four to eight weeks [9]. Typically, a 10 to 20% reduction from the baseline dose is performed each week or each fortnight in order to achieve this outcome.
If a patient was quite sensitive to withdrawal symptoms from an opioid step down approach, then consideration could be given to short term use of clonidine 75 µg fourth hourly for any severe withdrawal symptoms. Occasionally, there can be opioid withdrawal symptoms not controlled by clonidine, such as diarrhoea, which can be treated with loperamide, or nausea, which can be treated with prochlorperazine, or abdominal cramping, which can be treated with hyoscine.
In a number of cases, it will be desirable to consider improving the patient’s pre-existing poorly controlled pain. In this setting, it is not a recommended practice to commence another conventional pure mu opioid (which is ultimately likely to lead to the same scenario). Instead, consideration of using an atypical opioid can be clinically appropriate. The atypical opioid agents consist of tramadol [10], tapentadol [11] and buprenorphine [12] (which is available both sublingually and transdermally).
Atypical opioids can be started at a low dose and slowly titrated upwards. Each of these agents has a ceiling dose that helps clarify atypical opioid dose prescription. Typically, one would wait 6 weeks after elimination of the conventional pure mu opioid to assess the analgesic outcome from the titrated prescription of the atypical opioid.
Atypical opioids have an improved side effect profile in terms of reduction in serious adverse events (including mortality) and there is evidence of reduced tolerance and reduced opioid induced hyperalgesia (where high dose conventional pure mu opioids actually worsen pain as the dose is increased) [10-12].
If patients can feel that they are being empathically supported and that the deprescribing trial is exactly that, i.e. just a trial and that they are not going to be left with coping with increased pain, then they can be very open to the concept of reducing their conventional pure mu opioid medication [7, 13, 14]. As a patient said to me recently, “It was wonderful to finally remove the chemical handcuffs”.
Benzodiazepines are another class of agent that have been associated with serious adverse events and unclear therapeutic benefit and are another important class of agents to consider deprescribing for [15, 16]. This is especially the case in contemporaneous co-prescription of both opioids and benzodiazepines. Because of the benzodiazepine withdrawal profile, they may need to be withdrawn over a longer time frame with implementation of adjuvant cognitive behavioural therapy to manage any emergent anxiety and depression mood disorder.
If deprescribing is appropriate and has been undertaken but with difficulty in achieving the outcome, then it may be very worthwhile talking to a specialist pain medicine physician for advice on individual management.