Cyproheptadine is an antihistamine and antiserotonergic medication that works by blocking the action of histamine and serotonin. It acts as an H1 receptor antagonist, which is a key mechanism for its antihistamine effects, and also as a serotonin (5-HT2) receptor antagonist [1].
How does cyproheptadine relieve allergy symptoms?
By blocking histamine receptors, cyproheptadine prevents histamine, a substance released during allergic reactions, from binding to these receptors. This action reduces common allergy symptoms such as itching, sneezing, runny nose, and watery eyes [1].
What is cyproheptadine used for besides allergies?
In addition to allergic conditions like rhinitis and urticaria, cyproheptadine is sometimes prescribed off-label to stimulate appetite and promote weight gain in individuals with poor appetite or failure to thrive [2]. Its antiserotonergic properties are thought to play a role in this effect [1].
Does cyproheptadine have any other effects?
Cyproheptadine possesses anticholinergic properties, which can lead to side effects such as dry mouth, blurred vision, and urinary retention. It also has central nervous system effects, including drowsiness and dizziness [1].
What is the difference between cyproheptadine and other antihistamines?
Unlike many second-generation antihistamines that are more selective for peripheral H1 receptors and cause less drowsiness, cyproheptadine is a first-generation antihistamine. This means it readily crosses the blood-brain barrier and can cause significant sedation due to its central H1 receptor antagonism and antiserotonergic activity [1].
Are there any specific populations who should avoid cyproheptadine?
Cyproheptadine is generally not recommended for newborns and premature infants. Caution is advised in elderly patients due to an increased risk of anticholinergic side effects and central nervous system depression. It should also be used with care in individuals with glaucoma, peptic ulcers, or bladder neck obstruction [1].
Sources:
1. DrugPatentWatch.com
2. National Library of Medicine