Acute effects of hydroxyzine on nocturnal sleep and sleep tendency the following day: A C‐EEG study

Abstract

The acute hypnotic effects of hydroxyzine 25 mg and 50 mg nocte, were examined in six male and six female volunteers. Continuous electrophysiological measures (C-EEG) were taken to assess both nocturnal sleep and sleep tendency the following day. Both doses produced significant reductions in sleep onset latency and decreases in waking during sleep; reciprocal increases in sleep duration were also seen. Female subjects demonstrated a greater hypnotic response, including a dose-dependent decrease in sleep onset latency. Increases in sleep duration following both doses were significant for the female group alone. C-EEG measures of increased drowsiness the following day failed to achieve significance; although the largest effects on daytime sleepiness, including dose-dependent increases, were again seen with the female subject group and corresponded with subjective ratings. These results demonstrate the hypnotic efficacy of hydroxyzine, whilst failing to detect significant C-EEG hangover effects. However, variability in response to antihistamines, registered here as differences between the sexes, requires further consideration.

The diagnosis and management of rhinitis: An updated practice parameter

“…However, first-generation antihistamines dosed only at bedtime can be associated with significant daytime drowsiness, decreased alertness, and performance impairment. [320][321][322][323][324][325] In part this is because antihistamines and their metabolites have prolonged plasma half-lives, and their end-organ effects persist longer than plasma levels of the parent compound (Table VII). Consequently, an AM/PM dosing regimen, combining a second-generation agent in the AM with a first-generation agent in the PM, is not a preferred strategy for avoiding daytime drowsiness and performance impairment from antihistamine treatment in the management of allergic rhinitis.…”

“…307,309 In part because of prolonged plasma half-life and metabolites (Table VII), these undesirable and potentially dangerous side effects cannot be eliminated by administration of first-generation antihistamines only at bedtime. [320][321][322][323][324][325] Anticholinergic effects include dryness of mouth and eyes, constipation, inhibition of micturition, and an increased risk for provocation of narrow-angle glaucoma. Increased sensitivity and a greater incidence of pre-existing comorbid conditions, such as prostatic hypertrophy, elevated IOP, and cognitive impairment, place older adults in a high-risk category for the side effects of first-generation antihistamines.…”

H1-Receptor Antagonists

“…Although HI-antagonists such as ch10rpheniramine and hydroxyzine have long elimination half-life values and produce peripheral HIblockade for 24 hours after a single dose (Huang 357 et al 1982;Simons et al 1984;Yacobi et al 1980), their adverse CNS effects seem to wane 8 or more hours after administration (Alford et al 1992;Goetz et al 1991). The patient will be sleeping anyway during the night, thus sedation or impairment of CNS function will not cause any problems.…”

Non‐cardiac adverse effects of antihistamines (H1‐receptor antagonists)

“…Some physicians recommend giving first‐generation H 1 antagonists only at bedtime, as somnolence is of no concern during the night, and H 1 blockade may still be present the next morning. Unfortunately, the day after taking a first‐ generation H 1 antagonist at bedtime, the adverse CNS effects may not have necessarily disappeared and peripheral H 1 blockade does not necessarily persist [40 , 41 , 44]. Other physicians advise regular daytime use, anticipating that tolerance will develop to the adverse CNS effects, but not to the peripheral H 1 blockade [42].…”