What sleep parameters are decreased by antihistamines?

What sleep parameters are decreased by antihistamines?

• A. TST and N1
• B. REM and Sleep Latency
• C. SWS and REM latency
• D. Wakefulness

Answer: (B)

Antihistamines that cross into the brain reduce wake-promoting signals, leading to sedation. This sedative effect tends to make you fall asleep faster, so Sleep Onset Latency decreases. At the same time, these drugs suppress REM sleep, reducing the amount of REM sleep during the night. Put together, the most consistent changes you’d expect are less REM sleep and a shorter time to fall asleep. The first-generation, more sedating antihistamines show these effects most clearly, while newer ones are less likely to cause them.

Antihistamines that cross into the brain reduce wake-promoting signals, leading to sedation. This sedative effect tends to make you fall asleep faster, so Sleep Onset Latency decreases. At the same time, these drugs suppress REM sleep, reducing the amount of REM sleep during the night. Put together, the most consistent changes you’d expect are less REM sleep and a shorter time to fall asleep. The first-generation, more sedating antihistamines show these effects most clearly, while newer ones are less likely to cause them.