Can you take loratadine 20mg?

Yes, but why ?: Studies of loritadine show the medication is well tolerated at twice the recommended 10 mg dose. However, the same studies show no added benefit of the double dose in symptom relief over the regular dose schedule.

Not a problem: Yes, for most drugs the approved dose is the most effective. Loratadine is an exception. 10 mg is the approved dose in the USA, although the adult dose of Loratadine in other parts of the world is 20 mg. The 20 mg dose was the most effective dose but it caused 14% drowsiness. For marketing reasons, only 10 mg (european pediatric dose) was tested in the US in adults without drowsiness.