SEPTEMBER 3, 2017
Now that Spring is upon us let’s take a closer look at antihistamines. Histamine is a substance that our body releases when we are exposed to an allergen. An allergen is something that we are allergic to. Histamine makes our nose, ears, throat, eyes and skin itchy and sometimes swollen as well as making us sneeze and our nose run. These symptoms are our body’s way of getting the allergen out of us.
As the name suggests antihistamines act against histamine.
TYPES OF ANTIHISTAMINES
There are two types of antihistamines; the newer style non-sedating antihistamines and older sedating antihistamines. Sedate means to make drowsy.
WHEN CAN ANTIHISTAMINES BE TAKEN?
If you are experiencing symptoms such as those above then you can take an antihistamine. It will make the symptoms less severe as our body copes with the allergy.
Hay fever is one condition that can cause these symptoms. Others include hives (itchy swollen skin) and insect bites and stings.
Older sedating antihistamines are also commonly used to treat insomnia and prevent and treat travel sickness.
WHEN SHOULD ANTIHISTAMINES NOT BE TAKEN?
If someone suffers with severe allergies (anaphylaxis) antihistamines are not effective enough and an EpiPen (prescribed by a Doctor) should be used instead.
There is only one antihistamine that is Category A (safe) in the first two trimesters of pregnancy which is one of the sedating antihistamines, Polaramine.
Anyone with the rare disorder acute porphyria should not take an antihistamine.
Some people with kidney and liver problems should not take antihistamines.
Other reasons not to take antihistamines exist so always check with you Doctor or Pharmacist if you are not sure.
HOW TO TAKE ANTIHISTAMINES
There are many brands available of antihistamines so I will list the ingredient name as well as the original brand name. The most common non-sedating antihistamines fexofenadine (Telfast), loratadine (Claratyne) and cetirizine (Zyrtec) are taken once daily as they last 24 hours. Children over the age of one (Telfast and Claratyne) and two (Zyrtec) can be given these antihistamines.
The main sedating antihistamines are promethazine (Phenergan) and dexchlorpheniramine (Polaramine). These may be needed more than once per day. Children over the age of two can be given these antihistamines.
Of the other sedating antihistamines the one most commonly used for insomnia is doxylamine (Restavit).
SIDE EFFECTS OF ANTIHISTAMINES
Drowsiness is the main side effect and can happen even with non-sedating antihistamines in some people. Dry mouth and headache are also possible. These side effects usually don’t last long.