Loratadine (Claritin): uses, dosage & side effects

Follow the directions on the package for the dosing in adults and children. Use the dosing cup provided with the liquid formulation for children.

During an allergic reaction, your immune system releases a chemical called histamine, which is responsible for the symptoms of an allergy. Antihistamines work by opposing the actions of histamine, by stopping histamine from binding to its target sites in the body.

The chemical structure of non-drowsy antihistamines makes them less likely to enter the brain through what is known as the blood-brain barrier. This makes them less likely to cause drowsiness compared to other antihistamines.

Loratadine is not suitable for everyone. You should not take loratadine if you have previously had an allergic reaction to loratadine, desloratadine (a similar medicine), or another ingredient listed in the medicine. Loratadine should not be given to children under 2 years of age.

You should speak with your doctor before taking loratadine if you have liver or kidney problems, are pregnant or breastfeeding, have epilepsy or are at risk of having convulsions, have a metabolic disorder called porphyria, are due to have an allergy skin test or have problems absorbing or are intolerant to lactose or other sugars, as it may not be suitable for you. If you are pregnant or breastfeeding, we have a guide on taking antihistamines in pregnancy and breastfeeding.

Diabetics or people with phenylketonuria need to be careful when taking liquid and reditab forms of loratadine as they may contain sugar or aspartame. It may be best for them to avoid these formulations.

Loratadine can interact with other medicines, such as monoamine oxidase inhibitors, dalteparin, and ritonavir. If you take any prescription, over-the-counter or herbal medicines, we recommend you speak with your doctor or pharmacist to check if they are safe to take alongside loratadine.

Not everyone will experience side effects, but common ones include - nervousness (particularly in children), headache, drowsiness, increased appetite, and insomnia.

As with all medications, there is the potential for serious side effects, such as an allergic reaction. You should stop taking loratadine and seek urgent medical attention if you develop a skin rash, shortness of breath, wheezing, tightness in your chest or throat, or swelling of your tongue, mouth, lips, face, or throat.