Dilated blood vessels can cause nasal congestion (stuffy nose). Claritin-D is used to treat sneezing, runny or stuffy nose, itchy or watery eyes, hives, skin rash, itching, and other symptoms of allergies and the common cold.

“Claritin-D treats similar symptoms as Claritin,” Wozniak explains. “Both are used for the temporary relief of symptoms like sinus and nasal congestion and itching of the nose or throat. But because of the pseudoephedrine, Claritin-D also targets nasal congestion.”

Answer: Yes, it is ok to take the medication for an extended period of time. However, the "D" formulation has a decongestant (which is what the 'D' represents in the name) and this can raise your blood pressure. I would recommend discussing with your doctor if this will be a possible problem for you.

To prevent Claritin-D from keeping you awake, don't take it close to bedtime, recommends Mayo Clinic. Or, you can try switching to just Claritin (without the decongestant). “Unless you have a stuffy nose every single day, you might not need the pseudoephedrine,” Hill says.

Common Claritin side effects include headache, sleepiness, and fatigue. Less commonly, some people may experience dry mouth, dizziness, or an upset stomach. Claritin side effects are typically mild and can be managed at home. If they become too bothersome, stop taking Claritin and talk to your healthcare provider.

Take this medication by mouth as directed by your doctor, usually twice daily (every 12 hours) with a full glass of water.

Drug Label Information

The adult Claritin 24 Hour dosage is 10 mg (1 pill) by mouth once a day. Don't take more than 1 pill in a 24-hour period. If swallowing pills is tough, there are chewable tablets for adults that have the same directions, as well as ODTs. You can also take Claritin solution if you prefer.

Claritin® products are non-drowsy and can be taken at any time. Do not take more than one dose every 12 hours if you are using a 12-hour product, or one dose every 24 hours if you are using a 24-hour product. Always follow the label directions. See individual product pages for label directions.

Key Takeaways. Newer antihistamines like Allegra and Claritin are generally safe for daily use.

Cetirizine (brand Zyrtec) may cause drowsiness, so it may be better to take it before you sleep rather than during the day. Loratadine (brand Claritin) and fexofenadine (brand Allegra) are non-drowsy antihistamines that can be taken during the day.

Claritin® products are non-drowsy and can be taken at any time. Do not take more than one dose every 12 hours if you are using a 12-hour product, or one dose every 24 hours if you are using a 24-hour product. Always follow the label directions. See individual product pages for label directions.