Pharmacy Author: Omudhome Ogbru, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD

GENERIC NAME: loratadine

BRAND NAME: Claritin, Claritin RediTabs, Alavert, others

DRUG CLASS AND MECHANISM: Loratadine is a long-acting antihistamine that is used for the treatment of allergy. Histamine is a chemical that causes many signs and symptoms of allergy. Histamine is released from histamine-storing cells (mast cells) and attaches to other cells that have receptors for histamine on their surfaces. Histamine stimulates the cells to release chemicals that produce effects that we associate with allergy. Loratadine blocks one type of histamine receptor (the H1 receptor) and thus prevents activation of cells with H1 receptors by histamine. Unlike some antihistamines, loratadine does not enter the brain from the blood and, therefore, does not cause drowsiness when taken at recommended doses. The FDA approved loratadine in April 1993.

PRESCRIPTION: No

GENERIC AVAILABLE: Yes

PREPARATIONS: Tablets: 10 mg. Tablets, disintegrating: 5 and 10 mg. Tablets, chewable: 10 mg. Syrup: 5 mg/5 ml.

STORAGE: Tablets should be stored between 2°-30°C (36°-86°F), and syrup should be stored between 2°-25°C (36°-77°F).

PRESCRIBED FOR: Loratadine is used for the relief of nasal and non-nasal symptoms of seasonal allergic rhinitis. It is also used to treat patients with chronic urticaria, a type of allergic skin rash.

DOSING: The usual dose of loratadine is 10 mg daily for adults and children older than six years of age.

DRUG INTERACTIONS: Erythromycin, cimetidine (Tagamet), and ketoconazole (Nizoral) increase the blood concentration of loratadine by inhibiting the elimination of loratadine. This may result in increased adverse events from loratadine.

PREGNANCY: There are no adequate studies of loratadine in pregnant women. Loratidine should be used during pregnancy only if it is clearly needed.

NURSING MOTHERS: Loratadine is secreted in breast milk at levels similar to blood levels. Nursing mothers should decide whether to stop breastfeeding or discontinue loratadine.

SIDE EFFECTS: The most common adverse events with loratadine are headache, drowsiness, fatigue and dry mouth.

Reference: FDA Prescribing Information