Heidi's Claritin

Last April, Heidi started coughing a lot and having a lot of post nasal drip (that I could often hear her making gulping noises to try to get rid of). I finally took her to see a doctor (I think at the end of May) because it just wasn't going away. The doctor said that she probably has allergies and that I should give her some Claritin. I only give her 1/2 tsp at night before she goes to bed (which is when her coughing is the worst). After using the Claritin for a couple/few weeks, her coughing seemed to pretty much go away, so I stopped giving it to her. Then, her coughing and post nasal drip came back again. Sometimes she coughs so much that it sounds like she is going to vomit (from all of the post nasal drip, I guess). Anyway, I had to start her back on the Claritin again. I didn't want to keep giving it to her if I didn't have to. We just ran out of the small bottle that I bought, so I'm going to buy some more today. Poor Heidi. I was hoping that whatever was causing her allergies had maybe gone away since it was now summer, but I guess not.