Background: Nausea, vomiting and constipation are not considered classical symptoms of phaeochromocytoma and paraganglioma (PPGL), however are commonly reported by patients with PPGL due to the effect of catecholamine excess on colonic motility.1 Management of these symptoms at all stages of disease can be difficult due to risk of catecholaminergic crisis with many commonly prescribed medications.2 Currently, there is no guideline available to assist clinicians with managing this clinical challenge.
Aim: To develop recommendations for the safe management of gastrointestinal symptoms in patients with PPGL.
Method: A single centre retrospective analysis of the management of gastrointestinal symptoms in patients with PPGL treated at Peter MacCallum Cancer Centre Neuroendocrine Tumour Unit between 2019-2024 was completed. A literature review of gastrointestinal manifestations in PPGL was undertaken. Based on this, management recommendations for gastrointestinal symptoms in PPGL were developed.
Results: Twenty-four individuals with PPGL were included. Seventy-two prescription and fifty administration events of antiemetics occurred. Metoclopramide and dexamethasone were administered to ten and nine patients respectively. The majority of whom were alpha-blocked (n=7) or had a dopaminergic or non-secretory biochemical phenotype (n=10). No adverse hypertensive events related to serotonin (5HT3) antagonist, histamine (H1) antagonist, neurokinin (NK1) antagonist or dopamine antagonist use were recorded. A hypertensive episode occurred following high dose dexamethasone (10mg) administration in one individual with functional, metastatic paraganglioma with no alpha blockade prescribed. Published evidence of antiemetics precipitating catecholaminergic crisis and safe administration of antiemetics and prokinetics in PPGL was limited to case reports and a systematic review. Based on available evidence and our single centre analysis, we developed a framework to approach the management of gastrointestinal symptoms in PPGL.
Conclusion: Optimal management of gastrointestinal symptoms in PPGL should favour agents with low likelihood of stimulating catecholamine release and consider patient characteristics including use of alpha blockade and biochemical phenotype.