Related Experiment Videos
H1-antihistamines and the central nervous system
Michael J Welch1, Eli O Meltzer, F Estelle R Simons
1Allergy and Asthma Medical Group and Research Center, University of California, San Diego, San Diego, California, USA.
Clinical Allergy and Immunology
|July 13, 2002
Summary
Newer second-generation H1-antagonists are significantly less sedating than older ones, offering improved safety and efficacy for allergy treatment. These advanced antihistamines provide better benefit/risk profiles for patients.
Area of Science:
- Pharmacology
- Neuroscience
- Allergy Treatment
Background:
- First-generation H1-antagonists are known for adverse central nervous system (CNS) effects, primarily sedation.
- Significant interest exists in newer second-generation H1-antagonists due to claims of non-sedative properties.
- Evaluating CNS effects requires diverse assessments, from subjective drowsiness ratings to objective measures like EEG sleep latency and driving simulation.
Purpose of the Study:
- To differentiate the CNS effects of first-generation versus second-generation H1-antagonists.
- To assess the safety and efficacy profiles of newer antihistamines.
- To guide clinical recommendations for H1-antagonist use in allergic conditions.
Main Methods:
- Review of existing research on H1-antagonist CNS effects.
- Analysis of various CNS function assessments (subjective and objective).
- Comparison of first-generation and second-generation H1-antagonists at recommended dosages.
Main Results:
- Second-generation H1-antagonists demonstrate significantly less sedation compared to first-generation agents at recommended doses.
- Newer agents exhibit reduced blood-brain barrier penetration, high H1-receptor specificity, and minimal anticholinergic or other receptor effects.
- Second-generation H1-antagonists do not potentiate the CNS effects of alcohol or benzodiazepines.
Conclusions:
- Second-generation H1-antagonists offer a superior safety and efficacy profile due to their reduced CNS side effects.
- Benefit/risk assessments for newer agents should consider non-CNS effects, potency, onset, duration, administration ease, and cost.
- First-generation H1-antagonists are no longer the preferred choice for allergic rhinitis, conjunctivitis, or urticaria due to safety concerns.