Loratadine works by selectively blocking histamine H1 receptors. Histamine, a chemical released by your body during an allergic reaction, causes symptoms like sneezing, itching, and runny nose. By preventing histamine from binding to these receptors, loratadine effectively reduces these allergic responses.
Peripheral Action
This action is primarily peripheral, meaning it focuses on the histamine receptors in your tissues, rather than in the central nervous system. This selectivity contributes to loratadine’s generally non-sedating profile compared to some older antihistamines.
Specific Receptor Interaction
Loratadine’s affinity for H1 receptors is high, ensuring strong competitive inhibition of histamine binding. This means it outcompetes histamine for receptor binding, effectively silencing its allergic effects. The precise molecular interactions are complex, but the result is a clear reduction in allergic symptoms.
Therapeutic Consequences
The resulting therapeutic effect is a decrease in allergy symptoms such as nasal congestion, sneezing, itching, and watery eyes. This makes loratadine a useful treatment option for various allergic conditions.
