Antihistamines are commonly used to treat allergic reactions and some types of antihistamines help relieve the symptoms of sickness, vertigo and insomnia.
Allergic reactions include:
There are two main types of antihistamines:
These can affect your brain, causing you to become drowsy. An example of a sedating antihistamine is chlorphenamine maleate (eg Piriton).
The newer types of antihistamines have less of an effect on your brain and wont make you so drowsy. Acrivastine (eg Benadryl) is an example of a non-sedating antihistamine.
Your immune system protects you from harmful substances like bacteria and viruses by producing antibodies which help to remove these. In an allergic reaction, your immune system reacts to a harmless substance such as pollen, because it mistakes it as harmful and histamine is released. Histamine helps damaged tissue to heal, however it can also cause symptoms such as: a runny nose - itchy eyes, nose, throat and skin sneezing urticaria. Antihistamines work by blocking the effect of histamine in your body. This helps to prevent inflammation and eases allergic reactions.
If you have a severe allergic reaction, its important that you get medical help immediately as it can be very serious. You may then be given an injection of adrenaline, sometimes an injection of an antihistamine is used in addition to adrenaline.
Some antihistamines are available without a prescription (eg: chlorphenamine maleate (eg Piriton), loratadine (eg Clarityn) and cetirizine (eg Zirtek). Others are only available on prescription as they could have side-effects or interactions with other medicines you might be taking.
Depending on what you need antihistamines for; you can take them as tablets, liquids, nasal sprays or a cream. Only use creams for a short amount of time to avoid an allergic reaction and dont use creams on broken skin, unless your GP has said that you can do so.