5 tips for opioid prescribing in palliative patients

A blog post written by Lead Palliative Care Pharmacist Paul Tait

People living with a life-limiting illness, such as cancer, frequently report moderate to severe pain and describe in detail how it affects activities of daily living and quality of life. What matters most – be it spending quality time with grandchildren, time in the garden, or writing down their favourite life anecdotes – becomes hard work and wearisome in the face of uncontrolled pain. Yet in managing this beast that is pain, management with opioids has its own share of issues. Fortunately, with some thought at the point of prescribing, whether initiating or reviewing therapy, general practitioners (GPs) can anticipate these issues. Here are five tips to improve confidence with opioid use in the terminally ill.

1. Anticipate patient deterioration at the outset
Decline in function, as death approaches, is associated with variable ability to swallow. This poses a challenge with the administration of solid oral formulations, as swallowing deteriorates. In order to maintain good symptom control at this point, substitution with an oral liquid or subcutaneous formulation is necessary.

For some opioids, this full range of solid oral, liquid, and subcutaneous formulations is subsidised by the Pharmaceutical Benefits Scheme (PBS). For opioids where this full range is unavailable through the PBS, GPs have two options: (1) switch to an alternate PBS available medication, or (2) rely upon a costly (non-PBS) option. At a time of high caregiver stress and rapid patient deterioration, switching to an alternate medication may risk error.

GPs can anticipate loss of the oral route at the outset by choosing medicines wisely to ensure that subcutaneous alternatives are PBS-friendly when initiating oral opioids in the terminally ill. This will ensure this transition to oral liquid and subcutaneous formulations is both safe and affordable.

2. Partner with the patient and their caregiver
People with chronic pain achieve good analgesia from an appropriate combination of a long acting (maintenance) and an immediate release (breakthrough) opioid formulation. Tools such as diary notes or charts may be a useful strategy to engage both patients and their caregivers in pain management by documenting changes in patterns of breakthrough medicine usage.

While regular maintenance dose increases can be expected with time, so too should increases to the breakthrough dose. As a guide, a single breakthrough dose should correspond to around 10% of the total daily opioid prescribed amount.

3. Proactively respond to concerns of addiction
From time to time, people will ask about the addictive properties of opioids. While physical dependence and tolerance are expected consequences of long term opioid use, neither is predictive of addiction.

Addiction is rare in people using opioids to manage cancer; it is characterised by impaired control with drug use, compulsive use of a drug, continued use despite harm with a drug, and cravings. In fact, for most people the opioid will only offset the pain, with any euphoria being extremely mild or going unnoticed. While cautiousness is warranted when prescribing for people with a history of substance use, opioids should be utilised when clinically called for. Opioid contracts and consultation with state-based health departments may be helpful.

4. Manage constipation actively and pre-emptively
As death approaches, normal bowel function can be affected by insufficient fibre and fluid in diet, reduction in normal peristalsis, and poor abdominal-pelvic control. In the terminally ill, opioids exacerbate the underlying pathophysiology. A combination of a faecal softener and a bowel stimulant (e.g. docusate and senna) is the best choice to commence with when managing opioid-induced constipation. Stool softeners are ineffective when used alone. Where this combination is ineffective, macrogol sachets can be added to the regimen.

An Oxycodone-naloxone combination product (Targin®) aims to reduce opioid-induced constipation, yet the evidence is limited.

5. Identify reliable resources to guide opioid dosing and conversion
Table 1 lists a handful of reputable Australian resources designed to guide GPs with prescribing, switching, and monitoring of opioids. In addition to these resources, eviQ provides a free opioid conversion calculator. Clinicians need to register with the site prior to using the tool.

Table 1. Australian Opioid Dosing Resources

Pain often accompanies cancer and other life-limiting illnesses, affecting all aspects of life. GPs will use opioids routinely within this vulnerable patient group and need to approach prescribing confidently. When used appropriately and safely, opioids assist in the management of pain while making life more comfortable.



 
 Paul Tait is the Lead Palliative Care Pharmacist with Southern Adelaide Palliative Services at 
 the Repatriation General Hospital.