Loratadine is an antihistamine used to treat hay fever as well as skin conditions such as atopic dermatitis and hives. Taking it relieves symptoms such as sneezing, burning eyes, or itching. Compared to older antihistamines, loratadine has significantly fewer side effects because it is not sedating. In this respect, it is comparable to the active ingredient cetirizine, which is also used to treat hay fever.
Effect of the antihistamine
Loratadine – just like cetirizine – is a second-generation H1 antihistamine. Unlike first-generation antihistamines, loratadine and cetirizine do not affect the central nervous system (CNS) and thus do not have sedating properties. As a result, they cause fewer side effects than first-generation antihistamines. Loratadine blocks the histamine H1 receptors in the body and thus ensures that the neurotransmitter histamine can no longer bind to them. As a result, histamine cannot exert its effect, or at least not fully, and unpleasant symptoms such as reddening of the skin, burning of the eyes or itching do not occur.
Loratadine for hay fever and atopic dermatitis
In allergic rhinitis (hay fever), loratadine relieves typical symptoms such as sneezing, nasal flow, eye itching, and eye burning. It also has a decongestant effect on the nasal mucosa and is therefore also used for sinusitis. The active ingredient is also used more frequently for neurodermatitis. It reduces itching and ensures that the redness of the skin recedes. Similarly, the active ingredient can also relieve discomfort in other skin conditions such as hives, which are characterized by severe wheal formation on the skin.
Side effects of loratadine
When taking loratadine, relatively few side effects occur – compared to other antihistamines. This is because, unlike first-generation antihistamines, which often had a sedating effect due to their CNS-passivity, loratadine, like cetirizine, is not CNS-passive. Nevertheless, side effects can still occur as a result of taking both agents. Side effects that may become more common as a result of taking loratadine include headache, fatigue, nervousness, and an increase in appetite. Very rarely, allergic reactions, dry mouth, dizziness, nausea, gastritis, insomnia, hair loss, liver dysfunction, and cardiac arrhythmias have also been observed.
Dosage of Loratadine
Medications containing loratadine are available over the counter at pharmacies. They come in various dosage forms, including tablets and effervescent tablets. You should always discuss the exact dosage of the medicine with a doctor or pharmacist. Generally, the recommended dose for adults is ten milligrams once daily. Children can also be given ten milligrams, provided they weigh more than 30 kilograms. For children weighing less, five milligrams is recommended. Patients with liver damage should take each dose only once every two days. If you forget to take a dose, you can make up for it promptly. For example, if you usually take the active substance in the morning, it is also possible to take it in the afternoon or evening. If, on the other hand, the next intake time is imminent, you should not make up for the missed dose. Under no circumstances should you take two tablets at once.
Drug interactions and contraindications
Loratadine is broken down in the body by the enzyme CYP3A4. If substances that inhibit the activity of the enzyme are taken at the same time, this may increase the effect and side effects of the antihistamine. Interactions may occur with the following agents, among others:
- Ketoconazole (antifungal agents).
- Erythromycin (macrolide antibiotic).
- Cimetidine (H2 antihistamine)
- HIV protease inhibitors
- Propafenone
- Grapefruit juice
Loratadine must not be used if there is hypersensitivity to the active substance. In case of liver dysfunction, the active substance should be taken only under strict medical supervision, if at all. If you plan to have a skin test, the active ingredient should not be taken for at least two days before the test is performed. Otherwise, the results of the test may be falsified.
Pregnancy and lactation
If possible, loratadine should not be taken during pregnancy. So far, there are no reliable findings about whether the active ingredient can cause damage to the unborn child under certain circumstances. However, it is certain that it passes into breast milk during breastfeeding. The active ingredient should therefore only be taken during this period after a careful cost-benefit analysis by the attending physician. The decisive factor is that the benefit to the mother outweighs the possible harm to the child.
