Your Antihistamine Questions Answered

Here we answer all of your questions about antihistamines ranging from ‘can you take antihistamines every day?’ to ‘which is the best?’

Antihistamines, such as cetirizine, are medications which are most commonly used to alleviate and combat the symptoms of allergies, such as hay fever. They may also be used in other situations, such as to treat insomnia or to prevent motion sickness.

There are some antihistamines available over the counter in pharmacies, but some doses and some antihistamines are only available on prescription.

What are the different types of antihistamine?

Antihistamines are some of the oldest medications available and most commonly used. As such, there are many different types of antihistamine. It’s helpful to understand these different types so that you can choose the best one for what you need.

Predominantly, antihistamines are broken down into two main groups:

·Drowsy-making antihistamines

These are ‘old-school’ antihistamines which can make you feel sleepy (which indeed may be a desirable effect). Examples of these include promethazine (sometimes under the brand name Phenergan).

·Non-drowsy antihistamines

These newer antihistamines are better for some instances because they are far less likely to cause drowsiness. Examples of these include cetirizine, fexofenadine and loratidine.

How do antihistamines work?

When your body detects something coming in as harmful then it releases a substance called histamine. This is part of your immune response because the body is usually detecting something as a threat e.g. an infection. Histamine protects the body.

However, this system isn’t perfect for everyone! If you have allergies then your body mistakenly perceives something, such as pollen, as being harmful and releases histamine. This causes an allergic reaction as the blood vessels expand and you experience, potentially, itching, swelling, watery eyes, blocked or runny nose and rashes.

Antihistamines block what the histamine is doing, stopping the allergic reaction in its tracks. They can both stop the reaction happening in the first place (prevention) and reduce the effects (treatment).

What forms do antihistamines come in?

Antihistamines come in lots of different forms. You can usually take them as tablets or capsules; however, they are also often available as nasal sprays, eye drops, liquids, lotions and creams.

Which type of antihistamine is best?

There is no definitive answer to this question and it’s often a case of finding which antihistamine works best for your condition alongside anything else that’s unique to you (such as other medications you take and your lifestyle). It may be a case of trial and error to see which types work best for you.

Most people opt for non-drowsy antihistamines unless difficulty sleeping is one of your main symptoms. Pharmacists are usually excellent at giving useful advice about different antihistamines.

How do you take antihistamines?

Your antihistamines will come with a patient information leaflet and you should follow the instructions in it, or the advice of your doctor. Because there are so many different types of antihistamine, we cannot cover instructions for all. However, you should be clear from the instructions about:

• How to take this particular medication e.g. how to use the nasal spray or how many pills to take.
• When you should take the medication e.g. some should be taken at night or with food.
• How long you should take it for e.g. some are only designed for
  short-term use whereas others can be taken regularly or in the
  long-term.
• What you should do in the event you miss a dose or take too much.

Can you take antihistamines every day?

If you struggle with long-term symptoms, it is understandable that you may want to take antihistamines every day, either for a period of weeks or months, or indefinitely. It’s important to consider the different types of antihistamine because there are differences in how often they should be taken. Typically, you may consider:

• Taking them every day to manage your symptoms in the long term.
• Taking them only when your symptoms are difficult or disruptive.
• Taking them prior to being exposed to allergy triggers e.g. spending time with a particular animal.

Most experts agree that for most people with long-term allergy problems, taking an antihistamine every day can be safe. However, the biggest factor is to consider their side effects and ensure that they do not interact with other medications.

What are the side effects of antihistamines?

It’s usual for all medications to cause side effects. You’ll need to weigh up whether the side effects are tolerable for the symptom relief that they bring.

Side effects of drowsy-making antihistamines include:

• Drowsiness
• Poor coordination
• Reduced reaction speeds
• Difficulty with judgment
• Blurred vision
• Dry mouth
• Difficulty with urination

It is usually advised that you mustn’t drive or operate heavy machinery whilst taking this type of antihistamine. However, if you struggle to sleep because of your allergy symptoms, or your symptoms are worse in the early morning around 4 am – 6 am (as is common during allergy season), then taking one of these types of antihistamines at night can be beneficial.

Side effects of non-drowsy antihistamines include:

• Dry mouth
• Headache
• Nausea
• Drowsiness (although this is more unusual and usually less severe)

The patient information leaflet of the particular antihistamine will give a full list of potential side effects.

Can I take antihistamines with alcohol?

You shouldn’t drink alcohol when taking an antihistamine. This is particularly true if it is the type that makes you feel drowsy. Some antihistamines are dangerous if you take them and drink alcohol.

Can I eat and drink normally when taking antihistamines?

Apart from avoiding alcohol, you can usually eat and drink normally when taking antihistamines. Many antihistamines increase your thirst so keeping hydrated is helpful.

Can I take antihistamines with other medications?

There are some medications which don’t work well with antihistamines. This may be because together the medications can cause unwanted side effects, or because one medication may stop the other one from working effectively.

Common medications which need to be considered if you are taking antihistamines include antidepressants, cough and cold medications (which may also include antihistamine), and indigestion and stomach ulcer medications.

If you are taking other medications and want to take antihistamines, discuss what the best options are with your doctor or pharmacist.

Can everyone take antihistamines?

The vast majority of people can take antihistamines to alleviate symptoms. However, there are some instances when you’ll need to take extra care and should discuss your medication with your doctor:

• If you are pregnant or breastfeeding.
• If you want to give antihistamines to a young child, or to an older child in the longer term.
• If you are taking other medications.
• If you have a condition such as heart disease, kidney disease, liver disease or epilepsy.

It’s not usually the case that you won’t be able to take antihistamines at all, but extra care and guidance is needed.

Where can I get antihistamines from?

Various different antihistamines are available over the counter in weaker doses. You may need a prescription for some. At International Pharmacy we stock a range of different antihistamines and dispatch globally.

Please remember that all of our information is for guidance only and not a substitute for medical advice. Do ask your doctor or pharmacist if you need advice.