Does loratadine make you sleepy
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Does Loratadine Make You Sleepy?
Introduction to Loratadine and Sedation
Loratadine is a second-generation antihistamine commonly used to treat allergic reactions. Unlike first-generation antihistamines, which are known for their sedative effects, second-generation antihistamines are designed to minimize drowsiness. This article explores whether loratadine induces sleepiness based on various research studies.
Loratadine and Central Nervous System (CNS) Activity
Several studies have investigated the effects of loratadine on the central nervous system (CNS). Research comparing loratadine to diphenhydramine, a first-generation antihistamine, found that loratadine did not significantly reduce sleep latency or impair performance on cognitive and psychomotor tasks, unlike diphenhydramine, which increased sleepiness and disrupted performance efficiency 1. Another study using positron emission tomography (PET) imaging showed that loratadine had minimal binding to brain histamine H1 receptors, which are associated with sedative effects, and did not significantly increase subjective sleepiness compared to placebo 2.
Comparative Studies on Sedation and Performance
A comprehensive review of studies on loratadine's effects on cognition, psychomotor performance, mood, and sedation concluded that loratadine at a therapeutic dose of 10 mg per day did not produce significant CNS effects. The studies used various self-report measures and physiological indices, such as EEG-evoked potentials and sleep latency tests, and found loratadine's effects comparable to placebo 3. Additionally, a meta-analysis of multiple studies reported no increased risk of sedation with 10 mg of loratadine daily compared to placebo, although higher doses (20 mg and 40 mg) showed some impairment in specific performance tasks 45.
Loratadine in High-Performance Environments
Research conducted in high-performance environments, such as aerospace settings, also supports the non-sedative nature of loratadine. Studies using simulated cabin environments and various performance tasks found that loratadine did not significantly impair vigilance, tracking performance, or induce sleepiness compared to placebo. In contrast, diphenhydramine caused significant impairment in these areas 6.
Cognitive and Psychomotor Function
Further studies comparing loratadine to other antihistamines, such as fexofenadine and promethazine, demonstrated that loratadine did not cause significant impairment in cognitive and psychomotor functions. Promethazine, a first-generation antihistamine, showed substantial impairments, while loratadine's effects were similar to placebo 7. Another study confirmed that loratadine did not affect psychomotor performance, daytime sleep latencies, or subjective sleepiness, making it suitable for individuals involved in skilled activities and transportation 8.
Conclusion
In summary, the body of research consistently indicates that loratadine, at its recommended therapeutic dose of 10 mg per day, does not cause significant sedation or impair cognitive and psychomotor performance. This makes loratadine a suitable option for individuals who need to avoid drowsiness while managing allergic symptoms. Higher doses may have some sedative effects, but these are not typically encountered with standard therapeutic use.
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Most relevant research papers on this topic
Sedative effects of antihistamines.
Loratadine does not significantly affect central nervous system activity, while diphenhydramine increases sleepiness and disrupts performance efficiency.
RCT
Highly CitedBrain histamine H1 receptor occupancy after oral administration of desloratadine and loratadine
At therapeutic doses, desloratadine does not significantly bind to brain H1 receptors and does not induce significant sedation.
RCT
Rigorous JournalLoratadine: a non‐sedating antihistamine. Review of its effects on cognition, psychomotor performance, mood and sedation
Loratadine, a second-generation H1-receptor antagonist, has comparable effects on somnolence, fatigue, and mood without sedating the central nervous system, compared to diphenhydramine, a common first-generation antihistamine.
Literature ReviewHighly CitedLoratadine in the high performance aerospace environment.
Ingesting 10 mg of loratadine daily does not have sedative effects or impair cognitive-motor performance, but higher doses may show impairment.
Meta-AnalysisLoratadine in the high performance aerospace environment.
10 mg of loratadine daily does not cause sedation or impair cognitive-motor performance, but higher doses may impair driving and digit substitution tasks.
Meta-AnalysisEffects of loratadine/montelukast on vigilance and alertness task Performance in a simulated cabin environment
Loratadine/montelukast is similar to placebo in effects on daytime somnolence and psychomotor performance, but causes significantly less sleepiness and impairment of vigilance and tracking than diphenhydramine.
RCTRigorous JournalA double-blind, placebo-controlled investigation of the effects of fexofenadine, loratadine and promethazine on cognitive and psychomotor function.
Fexofenadine at doses up to 180 mg appears free from disruptive effects on psychomotor and cognitive function, unlike promethazine, which can impair these functions.
RCTHighly CitedStudies on performance and sleepiness with the H1-antihistamine, desloratadine.
Desloratadine (5 mg) does not negatively impact psychomotor performance, daytime sleep latencies, or subjective sleepiness, making it suitable for those involved in skilled activity and transportation.
RCTInitial and steady-state effects of diphenhydramine and loratadine on sedation, cognition, mood, and psychomotor performance.
Diphenhydramine may cause poorer cognitive performance and fatigue, potentially leading to decreased work productivity, while loratadine shows no significant differences in cognitive or psychomotor performance, mood, or sedation.
RCTHighly CitedComparatice effects of loratadine and selected antihistamines on sleep‐waking patterns in the cat
Loratadine is the least likely to produce adverse effects on the central nervous system compared to other antihistamines studied in cats.
Non-RCT
Animal Study