Loratadine: What It Treats and How to Use It Safely

If you have seasonal allergies, chronic hives, or just need reliable daytime relief, loratadine is one of the most common over-the-counter options. It’s an antihistamine that eases sneezing, runny nose, itchy eyes, and itching from hives without the heavy drowsiness many older antihistamines cause.

How loratadine works and when to take it

Loratadine blocks histamine, a chemical your body releases during an allergic reaction. You’ll usually feel it start to work within 1–3 hours, and one dose typically lasts about 24 hours. That makes it handy for once-a-day use—take it in the morning for daytime symptoms, or at any consistent time that fits your routine.

Common uses: seasonal allergic rhinitis (hay fever), perennial allergies, and chronic idiopathic urticaria (long-lasting hives). Don’t rely on loratadine for sudden, severe allergic reactions like anaphylaxis—seek emergency care and use an epinephrine injector if prescribed.

Practical dosing, safety tips, and interactions

Adults and kids 6 years and older: the usual dose is 10 mg once daily (tablets or syrup). For children 2–5 years, the typical dose is 5 mg once daily—follow the product label or your doctor’s advice. If you use a chewable tablet or liquid, measure carefully.

While loratadine is labeled “non-drowsy,” a minority of people still feel sleepy or dizzy. Avoid driving or heavy machinery until you know how it affects you. Also: alcohol and other sedatives can add to drowsiness, so use caution when combining them.

Loratadine is processed by the liver. Some medicines that change liver enzymes can raise loratadine levels (for example, certain antifungals or antibiotics). Tell your doctor about all prescription and over-the-counter drugs you take, especially ketoconazole, erythromycin, or strong CYP3A4 inhibitors. If you have liver or kidney problems, your doctor may suggest a lower dose or closer monitoring.

Pregnant or breastfeeding? Talk with your healthcare provider before using loratadine. Many doctors consider it safer than older sedating antihistamines, but personal medical history matters.

What to watch for: most people have no major issues. Mild side effects include headache, dry mouth, or fatigue. Stop using it and contact a doctor if you get signs of a serious allergic reaction, rapid heartbeat, or severe dizziness.

Want alternatives or comparisons? Diphenhydramine (Benadryl) acts faster but commonly causes strong drowsiness and lasts fewer hours. If loratadine doesn’t control your symptoms, a doctor may recommend a higher-strength or different antihistamine, combination therapy, or allergy testing.

Short tip: keep a small pack in your bag or medicine cabinet during allergy season, stick to the labeled dose, and check with your pharmacist or doctor if you’re taking other meds or have chronic health issues.

For more on allergy medicines and how they compare, check related guides on our site covering diphenhydramine, antihistamine choices, and safe online pharmacies.