Effects of modafinil and caffeine on night-time vigilance of air force crewmembers: A randomized controlled trial

Abstract

Background: Fatigue remains an important factor in major aviation accidents. Stimulants may counteract fatigue’s adverse effects, with modafinil as a promising alternative to caffeine. However, the effect of a single dose of modafinil after a limited period of sleep deprivation remains unknown. Aims: This study aims to determine the effect of 200 mg modafinil on vigilance during a limited period of sleep deprivation compared to 300 mg caffeine and placebo. Methods: Thirty-two volunteers of the Royal Netherlands Air Force (RNLAF) were double-blindly administered modafinil, caffeine, and placebo on three non-consecutive trial days after being awake for median 17 h. Afterwards, subjects completed six series of the Vigilance and Tracking test (VigTrack), psychomotor vigilance task (PVT), and Stanford Sleepiness Scale (SSS), yielding six primary endpoints. Results: This study revealed statistically significant effects of caffeine and modafinil compared with placebo on all endpoints, except for VigTrack mean tracking error. PVT results were less impaired 2 h after administration, followed by VigTrack parameters and SSS scores 2 h thereafter. Compared with caffeine, modafinil significantly improved PVT and SSS scores at 8 h after administration. Conclusions: The present study demonstrates that 200 mg modafinil and 300 mg caffeine significantly decrease the effects of a limited period of sleep deprivation on vigilance compared with placebo. Although PVT parameters already improved 2 h after administration, the most notable effects occurred 2–4 h later. Modafinil seems to be effective longer than caffeine, which is consistent with its longer half-life.

Comparison of effects of modafinil and caffeine on fatigue-vulnerable and fatigue-resistant aircrew after a limited period of sleep deprivation

“…This study is part of a larger randomized controlled trial, for an elaborate description of the materials and methods we therefore also refer to Wingelaar-Jagt et al (2023) ( Wingelaar-Jagt et al, 2023 ).…”

“…According to the design protocol of the study, their test results were included in the analysis. The subjects characteristics are equal to those described in the article about the comparison between the effects of modafinil and caffeine with placebo on night-time vigilance ( Wingelaar-Jagt et al, 2023 ): Subjects’ ages ranged from 25 to 59 years (median age: 30.9 years, IQR: 28.9–39.3 years). Among the 32 subjects, five (16%) were female, and a majority of 21 (66%) were pilots.…”

“…This study is part of a larger randomized controlled trial that was designed to investigate several aspects of the implementation of modafinil and caffeine as countermeasures for fatigue in (military) aviation. In a previously published manuscript about this trial, we concluded that both modafinil and caffeine significantly decrease the negative effects of an extended period of continuous wakefulness on vigilance compared with a placebo ( Wingelaar-Jagt et al, 2023 ). The present study compared the effects of modafinil and caffeine administration on the fatigue-vulnerable and -resistant participants of our population.…”

Cafeína e o sono: implicações neuroanatômicas e neurofisiológicas

“…Ademais, a cafeína pode efetuar uma função muito importante e necessária na aviação militar, em particular em ocorrências em que os pilotos já estão adinâmicos, mas ainda há necessidade operacional de continuidade de sua missão (Wingelaar-Jagt et al, 2023).…”

Modafinil: A closer look at its theoretical toxicological potential

“…Recently, an interesting article was published in Journal of Psychopharmacology in which the effects of modafinil and caffeine on the night-time vigilance of air force crewmembers who had limited sleep (Wingelaar-Jagt et al, 2023). The study found that both 200 mg modafinil and 300 mg caffeine significantly increase attentiveness during a prolonged period of continuous awake, including the early morning hours when people are least aware, as compared to placebo.…”