The influence of renal impairment on the pharmacokinetics of haloperidol has not been evaluated. About one-third of a haloperidol dose is excreted in urine, mostly as metabolites. Less than 3% of administered haloperidol is eliminated unchanged in the urine. Haloperidol metabolites are not considered to make a significant contribution to its activity, although for the reduced metabolite of haloperidol, back-conversion to haloperidol cannot be fully ruled out. Even though impairment of renal function is not expected to affect haloperidol elimination to a clinically relevant extent, caution is advised in patients with renal impairment, and especially those with severe impairment, due to the long half-life of haloperidol and its reduced metabolite, and the possibility of accumulation (see section ).
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Back in the early 90s, there was a big push to use a lot of lorazepam in the ICU because it was off patent and cheap and the others were on patent and expensive. Many of the papers extoling the virtues of lorazepam in Critical Care Medicine were thinly veiled advertisements. “Gee….we used a lot of it in the ICU and it worked just swell…..lets use more!!”. then look down at the bottom of the page and see “This advertisement brought to you by a grant from Wyeth, makers of lorazepam”. Delirium occurs when pattern recognition is lost in the ICU. Elderly people start running on pattern recognition at some point in their lives. They simply get used to their shrinking environment. Like a blind dog in your house. You never know the dog is blind. He knows the house and never bumps into anything. Then they land in an ICU and all that pattern recognition evaporates. And they might as well be on mars. Mild or incipient dementia takes over and they become confused and confounded and try to escape, following which they are quickly restrained and the race is on. Giving lorazepam simply decreases their ability to discern the thin grasp of reality, paradoxically increasing the delirium. Use a sedative you can titrate to effect. Propofol or study higher incidence of delerium when benzos and inadequate pain regiemn compared to dexmed (JAMA 2009;301(5):489)industry supported study states dex may be cheaper than midaz (Critical Care Medicine Issue: Volume 38(2), February 2010, pp 497-503)