Anti-diuretic for operational aircrew: effects of desmopressin on urine flow, cognition, and sleepiness.

INTRODUCTION: Air operations may demand missions of many hours, and aircrew may experience significant discomfort due to bladder distension. Attention has been given to the use of in-flight urination devices, but an alternative strategy could be reduction of urine flow by an anti-diuretic. In this event it would be important to establish an effective dose range free of adverse effects. METHODS: The effects of desmopressin (0.05, 0.10, 0.15, and 0.20 mg) on cognitive performance and sleepiness (multiple sleep latency test) from 1 to 11 h, and on urine flow up to 24 h after drug ingestion at 09:00, were studied in 20 healthy young volunteers. The study was double blind, placebo controlled, and with a randomized five-way crossover design. RESULTS: There was no evidence of impaired performance with desmopressin at or below 0.15 mg. All doses reduced urine flow up to 12 h after drug ingestion (p < 0.001), and the reduction appeared to be maximal at 0.10 mg. The dose range was free of adverse effects, except for the possibility of headaches, but they are unlikely to be of operational significance. DISCUSSION: Desmopressin could prove to be a significant advance in the management of urinary flow in operational aircrew. The dose could be as low as 0.05 mg with the option to use 0.10 mg in those less sensitive to the drug. Individual experience of the effect of the drug would be appropriate before use in flight, and guidelines concerning fluid intake would be needed. Further information may be required for use of the drug overnight.