Myth Buster #2 Lorazepam

Anyone who makes rounds with me know that when the topic of lorazepam (Ativan) as an anti-emetic comes up, I start to twitch.  It was during my oncology fellowship some 20 years ago that I remember the push began to add lorazepam to the various anti-emetic cocktails used as pre-treatment for emetogenic chemotherapy. The rationale was to use an anxiolytic to help reduce the incidence of anticipatory nausea--a not uncommon problem in those days when the available anti-emetics worked rather poorly.  Lo and behold, rather quickly lorazepam use metastatsized to treatment of post-chemotherapy nausea, and then, making the final evolutionary leap, to being used throughout hospitals and hospices for nausea of any etiology.  As best as I can find in the literature:  a) lorazepam is a very weak anti-emetic--the current edition of a major cancer textbook says "lorazepam has little efficacy as single agent in carefully conducted trials." (1)  b) lorazepam is effective at reducing anxiety--thus its efficacy in reducing chemotherapy-inducing anticipatory nausea or potentially for anxiety-induced nausea.  c) lorazepam is a sedative--as such, will put people to sleep and/or can induce delirium.  There just isn't the data to support the use of lorazepam as a major anti-emetic for non-anxiety nausea, and there is data on the potential harm of delirium or excessive sedation. For more on this topic, see Jim Hallenbeck's excellent Fast Fact #5 (www.eperc.mcw.edu)

1. Berger AM and Clark-Snow RA. Adverse effects of treatment. in DeVita  VT, et al. Cancer: Principles and practice of Oncology, 7th Edition. Lippincott Williams and WIlkins, 2005.