NIOSH Training for Nurses on Shift Work and Long Work Hours

Sleep Aids and Stimulants (Continued)

Many nurses drink caffeinated beverages routinely, without giving it much thought. You might use these as a pick-me-up in the morning or afternoon or to remain awake on the night shift. Caffeine is a stimulant, and when used judiciously it can aid alertness. However, it can also reduce sleep, so it is important to understand its properties.

Caffeine takes about 30 minutes (range, 15-45 minutes) to take effect and has a half-life of 5 to 6 hours but can remain in your system much longer.⁴ If you drink a cup of coffee near the end of a night shift, there can still be enough caffeine in your system to cause restlessness or waking while you are trying to sleep the morning after your shift. Notice how caffeine affects you as well as the caffeine content in your favorite drinks (see Table 6.1 and www.mayoclinic.com/health/caffeine/AN01211).