Clinical Outcomes Following Supply-Driven Transition From Intranasal to Oral Desmopressin in AVP-Deficiency-A Single...

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.

A retrospective study 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.

Forty two 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 mcg/day (IQR 10-20 mcg). Initial median oral dose before titration was 200 mcg/day (IQR 100-200 mcg); final median oral dose after titration was 200 mcg/day (IQR 162.5-300 mcg). 23/42 (54.8%) were switched initially using 1:10 ratio (10 mcg intranasal desmopressin to 100 mcg 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. Similarly, the findings of The Pituitary Foundation Impact Report demonstrated that the switch led to 121/161 (75.2%) of patients reporting poorer symptomatic control post-switch, and 76/161 (47.2%) requiring additional endocrine input.

45.2% (19/42) of patients achieved adequate symptom control post-switch with varying conversion ratios, and over half (13/23, 56.5%) of patients switched with an initial 1:10 conversion ratio reported symptomatic recurrence. Although a higher initial conversion ratio closer to 1:15 may reduce symptomatic recurrence in some patients, initiating treatment at a 1:10 ratio with careful up-titration represents a safe and pragmatic approach that minimises the risk of over-replacement and hyponatraemia, although inter-patient variability necessitates tailored titration. In parallel, national patient-reported data from The Pituitary Foundation Impact Report demonstrate the substantial patient and clinical burden of this supply-driven switch, highlighting the need for standardised guidance and prospective studies.