Desloratadine: What is it? How does it work? Administration, Side Effects, Interactions and Warnings

It is an antihistamine that relieves allergy symptoms, such as watery eyes, runny nose, itchy eyes/nose, sneezing, and hives.

It works by blocking the natural nucleus ( histamine ) that your body promotes while the allergic reaction is on.

Desloratadine is a prescription medication used to treat the symptoms of:

  • Seasonal allergic rhinitis: (sneezing, stuffy nose, runny nose, and itchy nose) in people two or older.
  • In people six months of age and older, there is perennial allergic rhinitis (sneezing, stuffy nose, runny nose, and itchy nose).
  • Chronic idiopathic urticaria: (long-term itching) reduces the number and size of hives in people six months or older.

Desloratadine is not for children under six months of age.

This medicine may be prescribed for other uses. Inform the specialist to know more about the medication.

Desloratadine works by blocking histamine release from human mast cells to help relieve sneezing, itching, runny nose, and watery eyes.

It comes in the form of a tablet and oral solution. Desloratadine is also available as oral disintegration tablets. It is usually taken once a day, with or without food.



  • If you are using the fast-dissolving tablet, let the tablet dissolve on your tongue and then swallow, with or without water.
  • Do not remove the tablet from the blister until just before use.
  • If you are using the liquid form of this medication, carefully measure the dose with a special measuring device/spoon.
  • Do not use household utensils since the measure of the drug would not be exact; the dose will be prescribed depending on the patient’s age, pathology, and response to the medicine.
  • Do not increase your dose or take this medication more often than directed.
  • Tell your doctor if your condition does not improve or if it gets worse.
  • Comply with the doses prescribed by your specialist; in case of forgetting the intake, do not bend the amount of the medicine.

Side effects

Desloratadine can cause side effects such as:

  • Fatigue.
  • Headache.
  • Dry mouth or throat.
  • Drowsiness.

Consult a doctor if these or other side effects are severe. For more information about possible side effects, see the package insert.

There are no reports of severe adverse reactions to the medication; in case of presenting any symptom other than the indicated ones, contact the nearest medical attention center to be treated as soon as possible.

When not to use Desloratadine?

It is not suitable for everyone and should not be used if:

  • You are allergic to Desloratadine or any other ingredient of this medicine.
  • Seek medical advice from your doctor if you have decreased kidney function.

For more information, consult your specialist, do not consume the medication without a prescription; it can cause side effects when interacting with other medicines.


Desloratadine may affect the functioning of other medications, and other medicines may affect the functioning of Desloratadine.

In particular, tell your doctor if you take:

  • Ketoconazole (Nizoral).
  • Erythromycin.
  • Azithromycin (Zithromax, Zmax).
  • Antihistamines.
  • Fluoxetine (Prozac).
  • Cimetidine (Tagamet).

Know the medications you take. Keep a list of your drugs and show it to your doctor and pharmacist when you receive a new medication.


Desloratadine should be used with caution in:

  • People with severe renal insufficiency.
  • People with an allergy to Desloratadine or any of the medication components.
  • People with hereditary galactose intolerance, lactase insufficiency, or glucose or galactose malabsorption.
  • Children under 12 years old.

Pregnancy and breastfeeding

It is not recommended during pregnancy.

Desloratadine (Azomyr, Opulis, Allex, Aerius) is the primary metabolite of loratadine.

Although a causal relationship between hypospadias (a urogenital anomaly) and products containing Desloratadine during pregnancy could not be confirmed or excluded, the product information for Desloratadine should be reviewed as a precautionary measure to indicate that its use during pregnancy is not recommended.

A separate review of products containing Desloratadine is underway.

Remember to consult your specialist for more information, do not meditate yourself.