Loratadine is an antihistamine medicine that relieves the symptoms of allergies. It's used to treat:

• hay fever
• conjunctivitis (red itchy eyes)
• eczema
• hives (urticaria)

It's also used for reactions to insect bites and stings and for some food allergies.

Loratadine is known as a non-drowsy antihistamine. It's much less likely to make you feel sleepy than some other antihistamines.

Loratadine is available on prescription. You can also buy it from pharmacies and supermarkets.

It comes as tablets or as a liquid that you swallow.

• It's usual to take loratadine once a day.
• Loratadine is classed as a non-drowsy antihistamine, but some people still find it makes them feel slightly sleepy.
• Children may also have a headache and feel tired or nervous after taking loratadine.
• It's best not to drink alcohol while you're taking loratadine as it can make you feel sleepy.
• Loratadine is also called by the brand names Clarityn Allergy and Clarityn Rapide Allergy.

Loratadine can be taken by adults and children aged 2 years and older.

Loratadine isn't suitable for some people. Tell your doctor or pharmacist if you:

• have had an allergy to loratadine or any other medicines in the past
• have severe liver failure
• have an intolerance to, or cannot absorb, some sugars such as lactose or sucrose
• have epilepsy or another illness that puts you at risk of fits
• have a rare illness called porphyria
• are booked to have an allergy test – taking loratadine may affect the results so you might need to stop taking it a few days before the test

If you or your child have been prescribed loratadine, follow your doctor's instructions about how and when to take it. If you've bought loratadine from a pharmacy or shop, follow the instructions that come with the packet.

How much to take

Loratadine comes as 10mg tablets and as a liquid medicine (labelled either 5mg/5ml or 1mg/1ml). You can take loratadine with or without food.

The usual dose in adults is 10mg once a day.

Doses are usually lower for people with liver problems.

For children, your doctor will use your child's weight or age to work out the right dose.

How to take it

Loratadine comes as 2 different types of tablet – ordinary and melt-in-the-mouth tablets.

Swallow ordinary loratadine tablets with a drink of water, milk or juice. If the tablet has a score line, you can break it in half if you find it hard to swallow it whole. Do not chew it.

Melt-in-the-mouth tablets dissolve instantly on your tongue without needing a drink. Be careful not to crush them when you take them out of the packet.

Loratadine liquid may be easier for children to take than tablets. The medicine will come with a plastic syringe or spoon to help you measure out the right dose. If you don't have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not give the right amount.

Loratadine tablets and melt-in-the-mouth tablets must only be taken by children aged between 2 and 12 years if they weigh 30kg or more. Give children loratadine liquid if they weigh less than 30kg.

When to take it

You may only need to take loratadine on a day you have symptoms, for instance if you've been exposed to a trigger such as animal hair. Or you may need to take it regularly to prevent symptoms, such as hay fever during spring and summer.

What if I forget to take it?

Take your forgotten dose as soon as you remember, unless it is nearly time for your next dose. Do not take a double dose to make up for a forgotten dose.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

Loratadine is generally very safe. Taking too much is unlikely to harm you or your child.

If you take an extra dose by mistake, you might get a headache, have a rapid heartbeat or feel sleepy. If this happens or you're concerned, contact your doctor.

Like all medicines, loratadine can cause side effects although not everyone gets them.

Common side effects

The most common side effect of loratadine is feeling sleepy. This happens in more than 1 in 100 people.

Side effects in children may include:

• headaches
• feeling tired
• feeling nervous

Serious allergic reaction

In rare cases, loratadine may cause a serious allergic reaction (anaphylaxis).

These are not all the side effects of loratadine. For a full list see the leaflet inside your medicines packet.

What to do about:

• Feeling sleepy – try a different non-drowsy antihistamine. If this doesn't help, talk to your doctor.
• Headaches – rest and drink plenty of fluids. Ask your pharmacist to recommend a painkiller. Headaches should normally go away after the first week of taking loratadine. Talk to your doctor if they last longer or are more severe.
• Feeling tired or nervous – talk to your doctor or pharmacist if these side effects don't go away as they may be able to offer you a different antihistamine.

It's generally safe to take loratadine during pregnancy and while breastfeeding.

For more information about how loratadine can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.

Loratadine and breastfeeding

It's usually safe to take loratadine if you're breastfeeding as only small amounts get into breast milk.

If you're breastfeeding and your baby was premature or has other health problems, talk to your doctor before taking loratadine.

Some medicines and loratadine interfere with each other and increase the chances of you having side effects.

Tell your doctor if you're taking:

• amiodarone, a medicine used to treat an irregular heartbeat
• cimetidine, an indigestion medicine
• erythromycin, an antibiotic
• ketoconazole, a medicine to treat fungal infections
• midodrine, a medicine used to treat low blood pressure
• ritonavir, a medicine used to treat HIV infection
• any medicine that makes you feel sleepy, gives you a dry mouth or makes it difficult for you to pee. Taking loratadine might make these side effects worse

Mixing loratadine with herbal remedies and supplements

There might be a problem taking some herbal remedies and supplements alongside loratadine – especially ones that cause sleepiness, a dry mouth or make it difficult to pee.