Medically Reviewed on 12/7/2022

Generic Name: loratadine

Brand Names: Claritin, Alavert, Claritin RediTabs, QlearQuil All Day & All Night 24 Hour Allergy Relief

Drug Class: Antihistamines, 2nd Generation

What is loratadine, and what is it used for?

Loratadine is a second-generation antihistamine drug used to relieve nasal and non-nasal symptoms of hay fever (seasonal allergic rhinitis) and to treat chronic itching from hives (chronic idiopathic urticaria).

Antihistamines work by blocking the activity of histamine, a natural chemical irritant in the body that causes allergy symptoms. Loratadine is available over the counter (OTC) in the U.S.

Histamine is a chemical released by mast cells and basophils, types of immune cells, in response to allergen exposure. Histamine binds to histamine H1 receptors, protein molecules located on cell membranes, and activates the immune response that results in inflammation and allergy symptoms. Loratadine binds to histamine H1 receptors, preventing their activation by histamine and the resultant allergic reactions.

Like other second-generation antihistamines, loratadine selectively binds to histamine H1 receptors primarily located on respiratory smooth muscle cells, cells lining blood vessel walls, the gastrointestinal tract, and immune cells. Loratadine does not cross the blood-brain barrier and has no central nervous system (CNS) effects, hence, it does not cause drowsiness, sedation, and impairment of psychomotor functions like first-generation antihistamines do.

Loratadine is approved for use in adults and pediatric patients of age 2 years and older, for the relief of nasal and non-nasal symptoms from:

Who should not take loratadine?

  • Do not use loratadine if you are hypersensitive to any of the components in the formulation.
  • Do not administer OTC cough medicines containing loratadine to children below 2 years of age and use with caution in children over 2 years.
  • Use with caution in elderly patients.
  • Use with caution in patients with impaired kidney or liver function.
  • Loratadine may potentiate the sedative effect of sedative drugs and alcohol if taken concurrently.
  • Some formulations contain benzyl alcohol which has been associated with a potentially fatal “gasping syndrome” in newborns. Use with caution.
  • Some formulations may contain phenylalanine, an amino acid. Take with caution if you have phenylketonuria, an inherited disorder with inability to metabolize phenylalanine.

What are the side effects of loratadine?

Common side effects of loratadine include:

Less common side effects of loratadine include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

  • Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
  • Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
  • Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
  • Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.


Allergies can best be described as: See Answer

What are the dosages of loratadine?


  • 5 mg/5 mL


  • 10 mg

Tablet, Chewable

  • 5 mg

Tablet, Disintegrating

  • 5 mg
  • 10 mg


  • 10 mg


Allergic Rhinitis

  • 10 mg orally once daily or 5 mg twice daily; not to exceed 10 mg/day


  • 10 mg orally once daily; not to exceed 10 mg/day

Dosing Considerations

  • Renal impairment (GFR below 30 mL/minute): 10 mg orally every other day
  • Hepatic impairment: 10 mg orally every other day


  • Children below 2 years: Safety and efficacy not established

Allergic Rhinitis

  • Children 2-6 years: 5 mg orally once daily
  • Children above 6 years: 10 mg orally once daily; not to exceed 10 mg/day


Children above 6 years: 10 mg orally once daily

Dosing Modifications

Renal impairment (GFR below 30 mL/minute)

  • Children 2-6 years: 5 mg orally every other day
  • Children 6 years: 10 mg orally every other day

Hepatic impairment

  • Children 2-6 years: 5 mg orally every other day
  • Children 6 years: 10 mg orally every other day


Claritin RediTabs: Dissolve on the tongue


  • Loratadine overdose can cause drowsiness (somnolence), rapid heart rate (tachycardia), and headache in adults, and palpitations and drug-related movement disorders (extrapyramidal symptoms) in children.
  • Overdose treatment is symptomatic and supportive care, which may include inducing vomiting or performing gastric lavage and administration of activated charcoal to eliminate any undigested drug and other measures as deemed necessary.

What drugs interact with loratadine?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe Interactions of Loratadine include:
    • mavacamten
  • Serious Interactions of Loratadine include:
  • Loratadine has moderate interactions with at least 133 different drugs.
  • Loratadine has mild interactions with at least 53 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • Animal reproductive studies show no fetal harm, however, there are no adequate and well-controlled studies on loratadine use in pregnant women. Use the lowest effective dose of loratadine during pregnancy, only if clearly needed.
  • Loratadine is present in breast milk. Make a decision to discontinue nursing or loratadine, taking into account the importance of the drug to the mother. If a breastfeeding infant is exposed to loratadine in breast milk, monitor the baby for drowsiness, jitteriness, and irritability.
  • Antihistamines may reduce milk production if administered before the establishment of lactation. 

What else should I know about loratadine?

  • Take loratadine exactly as prescribed, or as per label instructions if self-medicating with OTC drug.
  • Avoid concurrent use of alcohol and other sedative drugs with loratadine, it may potentiate their sedative effects.
  • Although second-generation antihistamines are generally non-sedating, loratadine may cause drowsiness. Exercise caution and avoid driving and other hazardous activities until the drug’s effects can be determined.
  • Store safely out of reach of children.
  • In case of overdose, seek medical help or contact Poison Control.

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Loratadine is a second-generation antihistamine drug used to relieve nasal and non-nasal symptoms of hay fever (seasonal allergic rhinitis) and to treat chronic itching from hives (chronic idiopathic urticaria). Common side effects of loratadine include headache, drowsiness (somnolence), fatigue, dry mouth (xerostomia), oral inflammation (stomatitis), abdominal pain, altered salivation, taste perversion (dysgeusia), loss of appetite (anorexia), gas (flatulence), indigestion (dyspepsia), constipation, diarrhea, and others. Do not take with alcohol or other sedative drugs. Consult your doctor if pregnant or breastfeeding.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 12/7/2022