Endocrine Abstracts

Introduction: Arginine vasopressin deficiency (AVP-D) requires lifelong desmopressin replacement. In March 2025, the national suspension of intranasal desmopressin necessitated urgent transition to oral alternatives. However, optimal conversion ratios and clinical response remain undefined. We evaluated clinical outcomes following this supply-driven transition.

Methods: A retrospective review at a tertiary UK centre (01/01/2025 – 01/07/2025) identified patients with confirmed AVP-D switched from intranasal to oral desmopressin. Demographic and clinical data were collected. Conversion ratios (intranasal: oral) were calculated before and after titration.

Results: 2 patients were included (mean age 52.6±2.3; 31% male). 15/42 (35.7%) isolated AVP-D; 11/42 (26.2%) partial hypopituitarism; 16/42 (38.1%) panhypopituitarism. Median intranasal desmopressin dose pre-switch was 10 mg/day (IQR 10 – 20). Initial median oral dose before titration was 200 mg/day (IQR 100 – 200); final median oral dose of 200 mg/day (IQR 162.5 – 300) after titration. 23/42 (54.8%) were switched initially using 1:10 ratio (10 mg intranasal desmopressin to 100mg oral tablet). 13/23 (56.5%) reported symptomatic recurrence, warranting further titration. The remaining 19/42 (45.2%) were switched initially using a median ratio of 1:20 (IQR 1:11.8 – 1:20). 10/19 (52.6%) reported symptomatic recurrence. Overall, switching from intranasal to oral desmopressin resulted in 16 patient calls, 79 additional blood tests and one hospitalisation.

The Pituitary Foundation’s Desmopressin Shortage Impact Report:

A national survey (n = 224) by The Pituitary Foundation found that most patients (75.2%) previously using intranasal desmopressin experienced poorer symptom control post-switch and nearly half (47.2%) required additional endocrine input, highlighting substantial patient and healthcare burden due to this shortage.

Conclusion: Only 45% (19/42) of patients achieved adequate symptom control post-switch, suggesting insufficient initial conversion ratios. A ratio closer to 1:15 may reduce symptomatic recurrence and subsequent dose titrations, although inter-patient variability necessitates tailored titration. This supply-driven switch increased clinical burden, highlighting the need for standardised guidance and prospective studies.