Claritin

Now, I understand the concept of "tolerance," where the body becomes accustomed to a certain medication and requires more of it to produce the same effect. I seem to have "reverse tolerance," if there is such a thing. I'm needing less Claritin to take care of my allergies. I tried a half-dose today... next time I need one, I think I'm going to try a quarter-dose.

Unlike Zyrtec, the physical side effects are fairly minor. I do get some itching with it, but it lasts less than 20 minutes, and is useful because it tells me that the Claritin is just wearing off. No heartburn. More of a dry mouth than with Zyrtec.

The mental side effects are starting to irritate me, though. The last time I took a full dose, I felt restless and anxious for most of the day. The restlessness I'd had before, but the anxiety was new. This last time I took a half-dose, and felt unsettled rather than anxious. Once I realize it was the medicine causing it, I settled down a bit, but it's still irritating. The half-dose was plenty for my symptoms, so maybe a quarter dose will knock it back down to just restless and still be enough for the allergies.

I just don't get why the effects have suddenly gotten worse when I've been taking the stuff all summer. I've been more careful with the Claritin than I was with Zyrtec, in that I never take a second dose until I'm sure the first has worn off. Generally, this is about two days later, despite the bottle saying it lasts "24 hours." I can tell due to the aforementioned minor itchiness. I also give any allergy symptoms about half an hour to go away on their own before taking it; any longer, and the Claritin won't work at all if I take it.

So... is there such a thing as reverse tolerance? I have no idea, but it sure doesn't sound right.