Antihistamines

Most people are able to take antihistamines.

However, antihistamines are not recommended for certain groups of people in some circumstances.

Health conditions and antihistamines

Certain conditions can be made worse by taking antihistamines, or they can cause the antihistamines to react unpredictably. These include:

• Asthma
• diabetes ( type 1 diabetes and type 2 diabetes )
• high blood pressure
• epilepsy
• heart disease
• liver disease
• kidney disease
• an overactive thyroid gland

Before taking antihistamines, seek advice from your GP or pharmacist if you haveahealthcondition.

Antihistamines in pregnancy

As a general rule, avoid taking any medication during pregnancy unless there's a clear clinical need. Always check with your GP, pharmacist or midwife first.

If you're pregnant and feel you need antihistamines, nasal sprays, nose drops or eye drops will at firstbe recommended. If these don't work, an oral antihistamine, usuallyloratadine orcetirizineis likely to be recommended.

Chlorphenamine is also considered safe to use during pregnancy,but should be avoided close to labour and childbirth as it can cause problems in the baby, such as irritability or tremor (shaking).

You should seek advice from your GP if your child is under two years old and you think they require treatment with antihistamines.

Some antihistamines are not recommended for children with certain conditions. For example, the National Institutefor Health and Care Excellence (NICE) recommends oral antihistamines aren't used routinely to treat children with atopic eczema .

Before giving your child any form of medication, read the patient information leaflet for advice about whether the medication is suitable for them.