The need-to-know information for Loratadine


Pearls and Fun Nuggets

1. Loratadine won’t usually make you drowsy ūüėī As a “non-sedating” antihistamine, loratadine causes less (but still significant, in some cases) sedation¬†and¬†psychomotor retardation¬†than the older antihistamines because it penetrates the¬†blood/brain barrier¬†to a smaller extent.[14]

2. It’s one of the weakest antihistaminesūüĎ∂ The potency of second generation histamine antagonists is (from strongest to weakest) desloratadine¬†(Ki¬†0.4¬†nM) >¬†levocetirizine¬†(Ki¬†3¬†nM) >¬†cetirizine¬†(Ki¬†6¬†nM) >¬†fexofenadine¬†(Ki¬†10¬†nM) > terfenadine > loratadine. However, the onset of action varies significantly and clinical efficacy is not always directly related to only the H1¬†receptor potency, as concentration of free drug at the receptor must also be considered.[17][16]

3. It almost became the first of it’s kind ūüéČ Schering-Plough¬†developed loratadine as part of a quest for a potential¬†blockbuster drug: a¬†nonsedating¬†antihistamine. However, by the time Schering submitted the drug to the¬†U.S. Food and Drug Administration¬†(FDA) for approval, the agency had already approved a competitor’s nonsedating antihistamine,¬†terfenadine¬†(trade name Seldane), and, therefore, put loratadine on a lower priority.[22]

4. The first Loratadine advertising commericials were very controversial ūüďį In the mid-1990s, the marketing team for Claritin at Schering-Plough found a way around the strict advertising regulations set by the FD. They created brand awareness¬†commercials that never actually said what the drug was for, but instead showed sunny images, and the¬†voiceover¬†said things like “At last, a clear day is here” and “It’s time for Claritin” and repeatedly told viewers to “ask your doctor” about Claritin.[27][28]

Patient Perspectives

“Cuts through a lot of my allergy symptoms (seasonal and cat dander). Once in a while, when the season is at its worst, I will feel a bit of stuffiness, but overall it has worked well for me.”


“Claritin Rapid Dissolve 1 tablet daily. Completely resolved sneezing, acute runny nose and watery eyes with no side effects. Benadryl didn‚Äôt touch them. Best second generation allergy medication I have ever tried.”


“Taken for itchy legs, but didn’t relieve itching at all, made me drowsy and lethargic, and gave me a headache! Rest of the pack is going in the bin.”

Brandon Simpson, PA-C
Follow me
Latest posts by Brandon Simpson, PA-C (see all)