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Antihistamines have become a household name for those seeking relief from allergy symptoms. From sneezing and itching to a runny nose, these medications play a pivotal role in managing allergic reactions.
What are antihistamines?
Antihistamines are medications that are used to treat allergy symptoms by inhibiting histamines. Histamines are responsible for symptoms such as sneezing and itching when exposed to common allergy triggers such as pollen, dust, pollution, and others.
When it comes to antihistamines, there are a few over-the-counter (OTC) choices available. Your doctor will prescribe what is right for your condition. The prevalent idea about allergy drugs is that they make you sleepy and tired, so it is critical to understand how they can affect your general health and avoid any negative consequences.
How Antihistamines Work?
Antihistamines are designed to counteract the effects of histamine. It works by blocking histamine receptors, thus, providing relief from allergy symptoms like:
· Itching
· Sneezing
· Running nose
First-generation antihistamines, like diphenhydramine, tend to cause drowsiness and are often used for nighttime relief.
Second-generation antihistamines, such as cetirizine and loratadine, are non-drowsy and suitable for daytime use.
Types of Antihistamines
First-generation antihistamines: They tend to cause drowsiness and are often used for nighttime relief. Diphenhydramine, chlorphenamine, and hydroxyzine.
Second-generation antihistamines: They are non-drowsy and suitable for daytime use.
· Cetirizine– Often used to treat the following:
o hay fever
o food allergies
o hives (urticaria)
o seasonal rhinitis
o permanent allergic rhinitis
o other allergy problems
It’s a non-drowsy option when compared to other allergy medications. Headaches, sleepiness, dry mouth, sore throat, coughing, and other side effects are possible.
· Loratadine- Like cetirizine, this is a non-drowsy medication. It helps reduce hay fever symptoms such as:
o Sneezing
o Coughing
o runny nose
o itchy/watery eyes
It is also prescribed for people suffering from:
o allergic rhinitis
o eczema
o chronic urticaria
Headaches, sleepiness, and other side effects are common.
· Fexofenadine– Helps relieve allergy symptoms such as watery eyes, sneezing, itching, and hives. It works by blocking the histamines that your body makes.
Combination antihistamine/decongestant: These formulations may include pseudoephedrine to address nasal congestion.
Do all OTC antihistamines work the same way?
Antihistamines function by preventing histamine from acting. Histamine is a naturally occurring substance in your body that is released in a variety of scenarios. One of these scenarios is when you have inflammation, such as when you have allergies. Itching, sneezing, and congestion can be caused by histamine release.
However, first-generation are not the same as second- and third-generation. First-generation can enter the brain. This is why they make you sleepy. However, second and third-generation antihistamines do not penetrate the brain as deeply.
Different OTC antihistamines are taken in different ways
There are several significant distinctions between the various classes of OTC antihistamines. Some of these main differences are as follows:
| First-generation | Second- and third-generation | |
| How long do they last | Generally 4-6 hours | 12-24 hours |
| Dosing | If used for allergies, it may be necessary to take it up to 4-6 times a day. | Taken 1-2 times daily for allergies |
| The best time to take them | If taken once a day, take it before bedtime. | Any time of day |
