The Efficacy of Claritin in Healthy Subjects

Subjects will be given Claritin 10mg tablet. Subjects will be challenged with histamine via
skin prick prior to Claritin administration and at 1 and 2 hours post administration. We will
measure and record wheal and flare area 10 minutes following each challenge.

Inclusion Criteria.

1. Males and females between 18 and 65 years of age.

Exclusion Criteria.

1. Pregnant or lactating women.

2. Upper respiratory infection within 14 days of study start.

3. Women of childbearing potential not using specific contraception method(s) (i.e.,
birth control pills, depo Provera, double barrier) as well as women who are
breastfeeding.

4. Patients with severe medical condition(s) that in the view of the investigator
prohibits participation in the study (heart, lung, kidney, neurological, oncologic or
liver disease).

5. Use of any other investigational agent in the last 30 days.

6. Use of medications that may affect skin testing. Specifically, subjects are excluded
if they have used an antihistamine during the 4 days preceding their treatment visit.