What are Antihistamines?
Antihistamines block the action of histamine, a chemical released by the body after it has been exposed to a trigger, such as pollen.
For most people antihistamines reduce the symptoms of their allergic reaction, such as sneezing or itchy, watery eyes.
Older-style sedating antihistamines, such as Piriton, are taken three to four times a day and can make you drowsy.Non-sedating antihistamines, such as loratadine (Clarityn) or cetirizine (Zirtek) are only taken once a day and do not cause drowsiness. Different brands work better for different people. Always ask your pharmacist to recommend which one is best for you. Ask for the generic brand – to get some savings for your pocket too!
How do Antihistamines work?
Histamine is kept in certain cells in the body known as ‘mast cells’. In an allergic reaction, these cells let the histamine leak into the blood and tissue, causing inflammation.
Antihistamines are chemical structures that work by blocking the action of histamine at special sites (receptors) in the skin, nose, blood vessels and airways.
Are they safe?
Older types of antihistamines, such as Piriton, are effective but can cause drowsiness. They could be dangerous if you're driving a car or working with machinery.
The newer drugs containing loratadine do not usually cause drowsiness.
Antihistamines generally have a good safety record and are available over the counter without a prescription. People with symptoms should take them regularly, not just on odd days when you feel bad. They work better if you take them right through the hay fever season.
Antihistamines come in nasal sprays and eye drops if you don't want to take tablets. These target specific parts of the body so are useful if you only get itchy eyes, for example. For children, some antihistamines are available as a liquid.