Used primarily as an antihistamine to relieve allergy symptoms such as sneezing, runny nose, and itching. It also has antiserotonergic properties, making it useful in treating conditions involving serotonin excess, such as serotonin syndrome. Commonly prescribed to stimulate appetite in patients with weight loss due to illness or medical treatments. Used off-label to manage insomnia and certain types of migraines. Has been applied in pediatric cases to counteract side effects of antipsychotic medications, such as drug-induced tremors. Also utilized in veterinary medicine for appetite stimulation in cats and dogs.