Brand: Alavert D-12, Claritin-D, Claritin-D 24 Hour, Leader Allergy Relief D-24, Do not use loratadine and pseudoephedrine if you have used an MAO inhibitor in the past Dilated blood vessels can cause nasal congestion (stuffy nose). mild dizziness;; dry mouth, nose, or throat;; nausea; or; sleep...