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If you’re prone to allergies then you already know what an antihistamine is. Antihistamines are medicines used to treat allergies and their symptoms. We sometimes dismiss allergies and think of them as something that only overly sensitive people have. The truth is that allergies can be fatal. That’s why it is important to know more about this medicine that can potentially save your life.

What are allergies?

Allergies are a number of conditions caused by the reaction of our immune system to typically harmless substances in our surroundings. Some of the most common types of allergies include hay fever, food allergies, allergic asthma, and anaphylaxis.

When someone experiences an allergic reaction, you often see them sneezing and coughing constantly even though they don’t have a cold. Some will have red eyes or itchy rashes. In extreme cases, allergic reactions can result in shortness of breath or swelling.

Based on data released by the American College of Allergy, Asthma, and Immunology; around 50 million people in the United States suffer from nasal allergies.

How do antihistamines fight allergies?

Your body produces chemicals called histamines. This happens when your body comes into contact with allergens, which are substances that trigger an allergic reaction. It can be pollen, pet dander, or dust mites. When your body produces histamine the tissue in your nose can begin to swell. This is when you feel your eyes and nose become runny. You will sometimes feel an itchy sensation in your mouth or rashes may appear on your skin.

If you think that only people prone to allergies have histamine then you’re wrong. We all have histamine in our bodies. Histamine is stored in cells called mast cells. The stored histamine gets released when your body reacts to a foreign substance or allergen.

Histamine binds itself to H-1 receptors when released. This binding sets off a chain reaction. This includes an increase in the blood flow to the affected area. Other chemicals also get released as an allergic response.

Antihistamines stop allergies by reducing or blocking histamine.

What are the different types of antihistamines?


Doxylamine is a type of antihistamine used to combat colds and allergies. It is also used as a sleeping aid. When used with Vitamin B6, it can be effective as a medication against morning sickness during pregnancy. This over-the-counter drug is one of the most powerful sedatives in the US.


Hydroxyzine works by reducing activity in the nervous system. You can use this if you need immediate relief for skin reactions like hives or contact dermatitis. It also works as a sedative to treat anxiety and tension.


These OTC antihistamines have anticholinergic properties. You can even combine it with other cold medications to provide relief for flu-like symptoms.


This is a sedative-hypnotic drug belonging to the phenylpiperazine group. Although this is an antihistamine, it is more popular as a sedative. Patients use this as a treatment for sleep disturbances. What makes this sedative unique is it is safe to use with children and adolescents. It has a favorable safety and tolerability profile. There is also no potential of abusing Niaprazine.


Pyribenzamine is a first-generation antihistamine. You can use this to treat asthma, hay fever, allergic rhinitis, and chronic urticaria. It is now less common because of newer types of antihistamines.

What are the side effects of antihistamines?

Aside from drowsiness, there are other side effects of antihistamines that you should be aware of. The most common side effects of antihistamines include:

  • Dry mouth
  • Dizziness
  • Nausea and Vomiting
  • Restlessness or moodiness
  • Confusion
  • Blurred vision

Can I use antihistamines as a sleeping aid?

Yes, people use antihistamines to help them fall asleep. If you’ve taken antihistamines before, you already know that it can cause drowsiness. This is one of the most common side effects of antihistamines.

If you check the labels of most over-the-counter sleep aids, you’ll find that they contain antihistamines. Keep in mind though that you should only use these sleep aids for around two to three nights at a time. You can safely use them when stress prevents you from sleeping. You can also use them when you’re traveling and having trouble sleeping in a new environment.

It is easy to develop a tolerance to the sedative effects of antihistamines. Their effects diminish when you take them frequently. Use them only as prescribed or when needed.

What can I expect when I use antihistamines as a sleeping aid?

Just like any other sleep medication, antihistamines can cause changes in a person’s Circadian Rhythm. This is your body’s natural sleep-wake cycle. You might feel a bit groggy the following day. Some say that the quality of antihistamine-induced sleep is not as good as that of natural sleep. However, these side effects might be a small price to pay for a good night’s sleep.

Get the advice of your doctor if you do decide to use antihistamines as a sleeping aid.. Although you can get over-the-counter antihistamines, your doctor can help you determine which one works best for you. You can then get a good night’s rest without any of the awful side effects.

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