Skip to 0 minutes and 9 secondsDr. Coulter, you're a consultant in palliative care. And like myself, prior to that, you were a general practitioner. So you've got a lot of experience of managing patients with cancer who are prescribed an opioid for their pain. Are there any common issues that you encounter in your practice? Yes, I do. From being previously in a primary care background, I've seen it obviously from initiation, and then obviously from continuation and secondary care. I think a lot of the problems I find tend to be about the initiation of opiates, and then the titration upwards. Initiation is obviously very important, because you have to decide on the safety of the drug in the first instance for the patient.
Skip to 0 minutes and 56 secondsand that is quite a complex assessment, but includes things like polypharmacy, what's the patient on, comorbidities, what is their current renal function, their falls risk. And I think anticipating any problems with counselling with the patient and their care is absolutely vital at this stage.
Starting a strong opioid
Although there are risks associated with strong opioids, they are relatively safe if used correctly.
In this video Drs Paul Coulter and Victoria Hewitt discuss common opioid-related issues they encounter in practice.
The dose has to be carefully titrated to avoid serious side effects such as respiratory depression. This is particularly important for patients who are not already taking a weak opioid, a state termed opioid naivety. Even if a weak opioid has been prescribed, you must always confirm with your patient and their carers if they are taking it as directed.
We are going to focus on morphine because it is the first-line opioid of choice. The principles are the same for other oral opioids, such as oxycodone. If the patient is unable to swallow, you should ask a specialist to advise how best to initiate a subcutaneous opioid.
If the patient is taking a weak opioid (at step 2 of the WHO analgesic ladder) this must be discontinued. The total daily amount of the weak opioid must be calculated and converted to the equivalent dose of morphine. In this situation the patient is not opioid naive and the prescriber will proceed as if they are titrating the morphine dose. Our patient, Terry, told his doctor that he stopped taking his co-codamol (weak opioid) due to constipation. Therefore we must consider him to be opioid naive and initiate morphine accordingly.
As well as acting on opioid receptors, tramadol inhibits the reuptake of serotonin and norepinephrine. Abrupt discontinuation can result in a withdrawal reaction, even if it is converted to a strong opioid. Therefore the tramadol dose must be carefully tapered and the strong opioid gradually increased.
Breakthrough pain (BTP)
This is pain which “breaks through” continuous, background analgesia. It can be associated with an event or action, such as eating or movement (“incident pain”). It can also occur when the background analgesia is inadequately controlling the pain. Thus the occurence of BTP is an important indicator of the effectiveness of an opioid for treating cancer-related pain. If BTP occurs the patient should take an appropriate dose of an immediate-release (IR) opioid in addition to their usual background analgesia. If BTP is not opioid-responsive, continuing the drug exposes the patient to unnecessary risk.
Some side effects, such as constipation, can be anticipated and proactively managed. Others require urgent medical attention. Clinicians should ensure the patient and their carers are aware of possible side effects and the signs and symptoms of opioid toxicity. Details of who to contact if these features develop must also be provided.
Methods of initiation
There are two methods for starting a patient on a strong opioid. The first uses an immediate release (IR) oral preparation. It is preferrable if your patient is at risk of becoming toxic or has previously experienced opioid side effects. The second uses a modified-release (MR) oral preparation and is slightly less complicated. Nevertheless, both methods consist of several steps and frequent reviews.
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