Loratadine

Generic name

Loratadine

Active ingredient

Loratadine

Product type

Small-molecule medicine

Drug class

Antihistamines

Brand names

UK Clarityn · US Claritin

Routes

Oral

Dosage forms

Tablet, Solution

Also known as

Clarityn, Claritin

Usual preparations

Tablets and a liquid medicine. (summary of the cited reference, not a prescription)

Onset and duration

The NHS says people may start to feel better within 1 to 3 hours of taking it.

Monitoring

The NHS and emc pages reviewed describe no routine tests or monitoring for loratadine.

Availability by country

Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.

What it is used for

• Symptomatic treatment of allergic rhinitis, the nose and eye symptoms of allergies such as hay fever
• Symptomatic treatment of chronic idiopathic urticaria (long-lasting hives with no identified cause)
• Relief of allergy symptoms in general, as the NHS describes it

How it works in the body

The NHS says loratadine blocks the effects of histamine, a chemical the body releases during an allergic reaction. It is described as non-drowsy because the NHS says it is much less likely to cause sleepiness than some other antihistamines, although some people still feel slightly sleepy. It eases the symptoms of an allergy rather than removing the allergy itself.

Cautions and interactions

• Pregnancy: the NHS says loratadine can be taken in pregnancy and advises checking with a pharmacist or doctor, and its antihistamines page says loratadine is usually recommended if an antihistamine is needed. The UK SmPC reports more than 1000 exposed outcomes showing no malformation or foetal toxicity, yet says it is preferable as a precaution to avoid loratadine in pregnancy.
• Breastfeeding: the NHS says only very small amounts of loratadine get into breast milk, while the UK SmPC says loratadine is excreted in breast milk and does not recommend its use in breastfeeding women.
• The UK SmPC says all known inhibitors of the liver enzymes CYP3A4 or CYP2D6 could raise loratadine levels. The NHS says to tell a pharmacist or doctor about other medicines, including amiodarone, cimetidine, erythromycin and any medicine that causes drowsiness, dry mouth or difficulty peeing.
• The UK patient leaflet advises that people with rare hereditary galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take the tablets.
• The UK leaflet says the tablets have not been shown to add to the effects of an alcoholic drink, but the NHS says it is best not to drink alcohol because it can make a person sleepy.
• The NHS says loratadine is unlikely to do harm if taken for a long time, but it is best taken only for as long as needed.
• The NHS says loratadine does not affect any type of contraception, including the combined pill and emergency contraception.

Interactions

Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.

No pair records for this medicine are in the sources currently represented by Anatomy Nexus. Absence from this list does not mean no interaction exists.

Same-class and related medicines

Same class: Antihistamines

Medicines that share the class of Loratadine. They are separate medicines with their own licences, doses and interactions, not alternative names for Loratadine.

Related medicines

Medicines often discussed alongside Loratadine: used together, compared with it, or acting on the same problem by a different route.

Key facts

What is loratadine used for?

Loratadine is an antihistamine that the NHS describes as non-drowsy and as relieving allergy symptoms. In the UK its licensed uses, according to the summary of product characteristics (SmPC), are the symptomatic treatment of allergic rhinitis and of chronic idiopathic urticaria. Allergic rhinitis is the medical name for hay fever and similar allergies that affect the nose, and urticaria is the medical name for hives. Chronic idiopathic urticaria means hives that last a long time without an identified cause. The NHS says loratadine can be bought from pharmacies and shops and can also be prescribed. It comes as tablets and as a liquid medicine, and the NHS gives Clarityn as the brand name. The UK medicines database (emc) holds product information for the tablets and for the syrup, both under the Clarityn Allergy name. MedlinePlus, a US source, lists loratadine (Claritin) among antihistamines that cause less sleepiness than others.

How does loratadine work?

When someone meets something they are allergic to, the body releases histamine, a chemical involved in the allergic reaction. The NHS says loratadine works by blocking the effects of histamine, which reduces allergy symptoms. It eases the symptoms of an allergy rather than removing the allergy itself. The NHS says loratadine is much less likely to make people sleepy than some other antihistamines, although some people still feel slightly sleepy. Even so, the NHS lists drowsiness as the most common side effect. The NHS says people may begin to feel better within 1 to 3 hours of taking it.

What are the side effects of loratadine?

Drowsiness is the most common side effect, and the NHS says trying a different non-drowsy antihistamine may help if it happens. The NHS says drowsiness happens in more than 1 in 100 people. If drowsy, the NHS advises not driving, riding a bike or using tools or machinery until fully alert and awake. The NHS says children may also get headaches. The UK patient leaflet lists headache, increased appetite and difficulty sleeping as common effects in adults and children over 12. Rarely, a person can have a serious allergic reaction (anaphylaxis) to loratadine itself. The NHS says to call 999 for sudden swelling of the lips, mouth, throat or tongue, very fast or struggling breathing, a tight throat or trouble swallowing, skin, lips or tongue turning blue, grey or pale, sudden confusion or drowsiness, or fainting. It also says not to drive yourself to A&E in that situation. MedlinePlus, a US source, lists rash, hives, itching, trouble breathing or swallowing, or swelling of the face, lips or throat as reasons to call a doctor right away. In the UK, NHS 111 or the GP the same day is the route for urgent advice that is not an emergency. One UK patient leaflet describes dizziness and nausea as very rare effects and advises contacting a doctor if fits occur.

Pregnancy, breastfeeding, other medicines and alcohol

The NHS says loratadine can be taken in pregnancy and advises checking with a pharmacist or doctor. Its antihistamines page says loratadine is usually recommended if an antihistamine is needed in pregnancy. The UK SmPC reports more than 1000 exposed outcomes showing no malformation or foetal toxicity, yet says it is preferable as a precaution to avoid loratadine in pregnancy. For breastfeeding, the NHS says only very small amounts of loratadine get into breast milk. The UK SmPC takes a more cautious line, saying loratadine is excreted in breast milk and that its use in breastfeeding women is not recommended. The NHS Specialist Pharmacy Service reports that occasional cases of reduced milk supply have been described with loratadine. According to the NHS, loratadine does not affect any type of contraception, including the combined pill and emergency contraception. The SmPC notes that inhibitors of the liver enzymes CYP3A4 or CYP2D6 could raise loratadine levels. The NHS says to tell a pharmacist or doctor about other medicines, including ones bought without a prescription, and names amiodarone, cimetidine, erythromycin and any medicine that causes drowsiness, dry mouth or difficulty peeing. The leaflet advises that people with rare hereditary galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take the tablets. The leaflet says the tablets have not been shown to add to the effects of an alcoholic drink, but the NHS says it is best not to drink alcohol because it can make a person sleepy. On long-term use, the NHS says loratadine is unlikely to do harm but is best taken only for as long as needed.

Frequently asked questions