Antihistamines are medications that disrupt the receptor for histamine, thus putting a stop to the symptoms that is triggered by histamine. These medications are commonly used to manage allergic rhinitis.
It is important to note that histamine is the chemical released by allergic cells in the body, typically as a response to an allergen such as pollen or cat dander. Once histamine is release by the allergic cells in the eyes and nose, it results to symptoms such as runny nose, sneezing, nasal congestion, postnasal drop and itchy nose, eyes and throat. These are the indications of hay fever or allergic rhinitis.
Types of antihistamines
The older variants or first-generation antihistamines include chlorpheniramine, diphenhydramine and hydroxyzine. These medications can cause detrimental side effects called anticholinergic that includes sleepiness, dry mouth and urinary retention. Due to the side effects, they are considered highly sedating for daytime use.
The newer versions known as second-generation antihistamines include loratidine, cetirizine, desloratidine and fexofenadine. These newer variants usually have reduced anticholinergic side effects and labelled as “non-sedation” or “low-sedating”.
What are the hay fever symptoms treated?
Since antihistamines work by blocking the action of histamine, most of the histamine-causing symptoms are managed by the medications such as runny nose, sneezing, itchy eyes, ears, nose and throat.
The other symptoms including cough, postnasal drip and nasal congestion can also be triggered by histamine and managed with antihistamines. Nevertheless, the medications are essentially less effective in managing postnasal drip and nasal congestion since other chemicals other than histamine are involved.
Which causes the least sedation?
When it comes to sedation, it is a vital factor when it comes to antihistamines. Sedation refers to a tired feeling which is different from impairment in which the ability of an individual to perform physical and mental tasks is affected.
The only non-sedating antihistamine available in the market is Allegra. As for Zyrtec, it can cause sedation more often. Remember that none of these second-generation antihistamines when used in the recommended dose for allergic rhinitis can trigger impairment. This is in comparison to the older variants such as Benadryl which can lead to impairment of both physical and mental tasks.