Loratadine is a drug used to treat allergies, and marketed for its non-sedating properties. It is marketed by Schering-Plough and Shionogi in Japan under several trade names such as Claritin, Claritin-D, Claritine, Clarityn, Clarityne or Fristamin depending on the market; by Cadila as Lorfast; by Lek as Lomilan or Flonidan; by Sandoz as Symphoral; by Ranbaxy as Roletra; by Pliva as Rinolan; by Teva as AllergyX; by Wyeth as Alavert; and by Pharma International as Tidilor. It is also available as a generic. In a version marketed as Claritin-D or Clarinase, loratadine is combined with pseudoephedrine, a decongestant; this makes it somewhat useful for colds as well as allergies, but adds potential side-effects of insomnia, nervousness and anxiety.

XL sells the Loratadine under the brand name ALLOR 10 in Vietnam

It is considered a second generation agent.

Regulation and clinical trials

Schering-Plough developed Loratadine as part of a quest for a 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, Seldane (terfenadine), and therefore put Loratadine on a lower priority as a "me too" drug.[http://query.nytimes.com/gst/fullpage.html?res=9C07E0D7103BF932A25750C0A9679C8B63&sec=health&spon=&partner=permalink&exprod=permalink The Claritin Effect; Prescription for Profit - New York Times ] Trials also raised questions about whether there was any dose at which Loratadine was simultaneously nonsedating and highly effective. Reviewing a randomized, double-blind trial, Dr. Sherwin D. Straus of the FDA argued at one point that "10 milligrams is not very different than placebo clinically," and that the reason for making the dose so low was that at higher, more effective doses, it became sedating. Schering counters that "The innovation of Claritin and the basis for its success are not only that it works, but also that it was the first antihistamine to provide effective relief of allergy symptoms without sedation and with an impeccable safety profile."

Loratadine was eventually approved by the FDA, and in 2001, its last year on patent, it accounted for 28% of Schering's total sales. Although an FDA advisory panel ruled that Loratadine was safe enough to be sold over the counter, Schering opposed such a decision on the grounds that it would reduce the price that could be charged for the drug. The drug continued to be available only by prescription in the U.S. until it went off patent in 2002. It was then immediately approved for over-the-counter sales. Once it became an unpatented over-the-counter drug, the price dropped precipitously, and insurance companies no longer paid for it. In response, Schering launched an expensive advertising campaign to convince users to switch to Clarinex (Desloratadine), which is a metabolized form of Loratadine. A 2003 study comparing the two drugs found that "There is no clinical advantage to switching a patient from loratadine to desloratadine. However, it may be an option for patients whose medical insurance no longer covers loratadine if the co-pay is less than the cost of the over-the-counter product."