I have all the symptoms of seasonal allergy, itchy watery eyes, scratchy voice, sneezing multiple times, clear runny nose, some coughing. I took one Claritin 10mg 24 hr non drowsy tablet and became so exhausted all I could do was come home and go to sleep for 5 hrs. The exhaustion was far more than I expected from a non drowsy tablet. Should I take another tablet tomorrow or just take it when the symptoms appear or should I just take a half of this tiny tablet or try something else. I had a TJR of my knee over a month ago and have been taking some Percocet and Tramadol but haven't needed any for over 24 hrs so doubt this is interacting but maybe you have a better suggestion. I am generally a healthy 71 yr old who has no other drugs that I take but I do take vitamins and make protein shakes daily with lots of probiotics daily.