Carcinoid Syndrome Not Controlled by Somatostatin Analogues: What to Do Next
Somatostatin analogues (SSA) are the established first-line therapy for carcinoid syndrome (CS). When SSA fails to achieve adequate symptom control or biochemical targets, a structured escalation approach is indicated. This page outlines the clinical situation and the direction taken at this stage.
First-line SSA therapy — octreotide LAR or lanreotide Autogel — did not achieve maximal symptom control (resolution of flushing and diarrhoea), normalisation of u5-HIAA levels, or adequate control of tumour burden. The protocol below addresses the next step after this failure.
The evidence-based approach involves optimising the SSA regimen — SSA should not be discontinued — and may include the addition of an oral agent that acts on serotonin synthesis. The complete structured regimen, including sequencing and decision criteria, is available via the link below.
References
DOI: 10.1111/jne.13146
- SSA should be continued, with their dosage being optimised.
- Worsening of CS 2–3 weeks after SSA injection may imply tachyphylaxis; more frequent doses, increased octreotide LAR dosage, or switching to the alternative SSA can be considered.
- Telotristat ethyl (an oral inhibitor of tryptophan hydroxylase, the rate-limiting enzyme of serotonin synthesis), significantly reduced RCS-associated diarrhoea and u5-HIAA in clinical trials and in real-world patients.