Serious Adverse Drug Reactions to Long-Term Oral Liquid Morphine in Patients with Chronic Pain: A Cross-Sectional Survey in Palliative Care.

BACKGROUND

Behaviour suggestive of addiction in some patients on long-term oral liquid morphine (OLM) caused concern amongst the Hospice Africa Uganda clinical team and prompted the survey. This survey aimed to identify serious adverse drug reactions to long-term OLM in patients with chronic pain receiving palliative care.

METHODS

In Phase 1, the database of patients receiving palliative care at Hospice Africa Uganda was analyzed to find patients taking OLM from 12.7.2017 to 19.10.2017. A purposive review of their medical records was undertaken to identify those on long-term OLM. Phase 2 was conducted between 12.6.2018 and 23.10.2018. All patients on long-term OLM were offered biopsychosocial and spiritual assessment by a pain specialist (BD) to determine whether they were experiencing any serious adverse drug reactions. Phase 3 immediately followed phase 2 assessment. The pain specialist discussed with the participant any medication changes (including OLM) or other therapies to facilitate holistic management of pain for the individual.

RESULTS

In phase 1, 653 patients on OLM were identified. Phase 2 identified 49 patients who were on long-term OLM. Thirty-four patients agreed to participate in the assessment with the pain specialist. Of the 34 participants, 24 had chronic non-cancer pain and two had chronic cancer pain. Eight cancer survivors had incidental chronic non-cancer pain. Serious adverse drug reactions were identified in four participants with chronic non-cancer pain. Two cases of addiction, one case of opioid hyperalgesia, and one probable diversion of morphine.

CONCLUSION

To our knowledge, the study identified the first documented cases of addiction to OLM in sub-Saharan Africa. Future research involving a larger multicenter sample, longitudinal, and qualitative designs is needed. Education of healthcare practitioners prescribing opioids should put equal emphasis on management of chronic non-cancer pain as do chronic cancer pain to minimize the risk of serious adverse reactions.