I had a severe TBI Aug. 18th 2014. I have frontal lobe, and vestibular nerve damage. My neurologist has me on 1mg Clonazepam for anxiety and vertigo. Ever since my tbi my body gets use to or medications do not seem to work right. I do have elevated liver enzymes, high cholesterol and hypothyroidism. I am 5' 4" and weigh 186ibs. I have searched for a year now as to what causes a medication to either not work or don't get the full effect of it. Nothing in the medical text books give me any information. My family physician is still researching. I had lab run off to test for hep. but it came back negative. I don't understand how a medication just stops working.