Daily Naltrexone Use Does Not Adversely Affect Physical, Cognitive or Marksmanship Performance in U.S. Army Soldiers

• Published in: Military medicine 2024-02, Vol.189 (3-4), p.e515-e521
• Main Authors: Carreno-Davidson, Jamie T, Castellani, Colleen M, Carreno, Joseph J, DeLuca, Jesse P, Selig, Daniel J, Vuong, Chau V, Pasiakos, Stefan M, Ritland, Bradley M
• Format: Article
• Language: English
• ISSN: 0026-4075; 1930-613X
• DOI: 10.1093/milmed/usad325

ABSTRACT Introduction Considering the potential of weaponized opioids, evaluating how prophylactic countermeasures affect military-relevant performance is necessary. Naltrexone is a commercially available Food and Drug Administration–approved medication that blocks the effects of opioids with minimal side effects. However, the effects of naltrexone on the health and performance of non-substance abusing military personnel are not well described in the existing literature. Methods Active duty U.S. Army Soldiers (n = 16, mean ± SD, age: 23.1 ± 5.3 y) completed a series of physical, cognitive, and marksmanship tasks during a 4-day pretrial, a 7-day active trial, and a 4-day post-trial phase. During the active trial, participants were administered 50 mg of oral naltrexone daily. Physiological and biological processes were monitored with a daily review of systems, sleep monitoring, biochemistry, and hematology blood panels. Results Naltrexone did not negatively affect physical performance, cognitive functioning, marksmanship, or sleep duration (P > 0.05). Improvements were observed during the active trial compared to the pretrial phase in cognitive tasks measuring logical relations (P = 0.05), matching to sample (P = 0.04), math speed (P