What is loratadine/pseudoephedrine? How does it work (mechanism of action)?

  • Loratadine/pseudoephedrine is a combination of two drugs, an antihistamine (loratadine) and a decongestant (pseudoephedrine). Loratadine is a long-acting antihistamine that blocks the actions of histamine that causes some of the symptoms of allergic reactions. 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 are associated with allergy symptoms. 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. It is one of a few antihistamines that do not cause sedation. Pseudoephedrine decongests tissues by causing blood vessels to constrict.
  • Alavert Allergy & Sinus, Claritin-D, Claritin-D 24 hour, and many others are brand names for loratadine and pseudoephedrine.
  • The combination of loratadine and pseudoephedrine is available in generic form and is available over-the-counter (OTC) without a prescription.

What is loratadine/pseudoephedrine used for?

Loratadine/pseudoephedrine is a combination of two drugs, an antihistamine (loratadine) and a decongestant (pseudoephedrine).

What are the side effects of the combination of loratadine and pseudoephedrine?

Side effects of loratadine/pseudoephedrine include:

What is the dosage for the combination of loratadine and pseudoephedrine?

  • Loratadine/pseudoephedrine may be taken with or without food.
  • It must be used cautiously in patients with heart (coronary artery) disease and angina (because pseudoephedrine can stimulate the heart) as well as in patients with diabetes (because there is a small chance that pseudoephedrine can raise the level of blood sugar).
  • The dose for children older than 12 years and adults is 1 tablet every 12 hours of immediate release tablets or 1 tablet every 24 hours for extended release tablets.


Could I Be Allergic? Discover Your Allergy Triggers See Slideshow

Which drugs or supplements interact with the combination of loratadine and pseudoephedrine?

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Is loratadine and pseudoephedrine safe to take if you are pregnant or breastfeeding?

Pseudoephedrine is secreted in breast milk. The American Academy of Pediatrics considers pseudoephedrine to be compatible with nursing.

What else should you know about loratadine and pseudoephedrine?

What preparations of loratadine and pseudoephedrine are available?

Tablets containing 5 mg loratadine and 120 mg pseudoephedrine (12 hour formulation) and tablets containing 10 mg loratadine and 240 mg pseudoephedrine (24 hour formulation) are available.

How should I keep loratadine and pseudoephedrine stored?

Tablets should be stored at 15 C to 30 C (59 F to 86 F).


Allergies can best be described as: See Answer

Medically Reviewed on 11/14/2019


Medically reviewed by Eni Williams, PharmD, PhD.

FDA Prescribing Information.