Use in palliative care
Opioid interactions with concomitant medications and their effects on concomitant disease
There are a number of concomitant diseases (and medications for their treatment) that can interfere with the efficacy and safety of opioids. In turn, physicians need to be aware of the potentiating effects that opioids can have on certain concomitant diseases and medications.
This is an area that requires good management and communication between all members of the multidisciplinary team to ensure that the patient's full medical profile is known in order to assess the appropriate use of opioids.
Depression is quite common in palliative care patients, and the opioid class of drugs is known to potentiate the effects of anti-depressants, as well as sedatives, tranquilisers and hypnotics. Careful monitoring should be conducted, and dose adjustments made to avoid adverse effects such as sedation. In addition, opioids should not be used concomitantly with monoamine oxidase inhibitors (MAOIs) or within 2 weeks of their discontinuation.
Patients with respiratory depression, chronic obstructive airways disease, chronic bronchial asthma or heart failure secondary to chronic lung disease should not be prescribed opioids.
Opioids are known to impair intestinal motility, so should be discontinued in patients with paralytic ileus, chronic constipation and delayed gastric emptying. Elderly patients are likely to have gastointestinal dysmotility due to diseases, medications and lifestyle changes, and opioids can contribute to this, so physicians may need to consider methods to avoid constipation (e.g. changes to diet, stool softners and laxatives.).
Patients with other gastointestinal problems, such as dyspepsia, may be receiving drugs that inhibit cytochrome P450-3A4 inhibitors which can inhibit the metabolism of opioids.
Opioids should be used with caution or in reduced doses in patients with chronic renal and hepatic disease, and in those with hypertension, as opioids potentiate antihypertensives.
Where appropriate, specialists should be consulted for advice on any potential complications of opioid use and concomitant disease, and if necessary, when initiating opioid treatment.