Hello, I have been taking lisinopril-HCTZ 10 12.5 for 4 days and I feel kind of crummy. Very tired and like I m getting the flu. I don t have fever, nausea, headache, etc. and I don t feel weak. Just very, very tired and the way I feel just before I get full blown flu. About how long does it take on average for a body to adjust to the medication? Thank you!