Intravenous Lorazepam versus dimenhydrinate for treatment of vertigo in the
emergency department: a randomized clinical trial.
Author(s): Marill KA, Walsh MJ, Nelson BK.
Affiliation(s): Department of Emergency Medicine, Texas Tech University Health Sciences Center,
El Paso, TX, USA. marilk01@med.nyu.edu
Publication date & source: 2000, Ann Emerg Med. , 36(4):310-9
STUDY OBJECTIVE: To determine whether lorazepam is more effective than
dimenhydrinate in relieving the symptom of vertigo in the emergency department
setting.
METHODS: A prospective, randomized, double-blind trial of intravenous lorazepam
versus dimenhydrinate therapy was conducted in the ED of a county-owned,
university-affiliated hospital. All adult patients who presented between January
24, 1998, and May 23, 1999, with the symptom of vertigo were eligible for
inclusion. The intervention was varying the intravenous treatment between
lorazepam, 2 mg, and dimenhydrinate, 50 mg. All patients received intravenous
infusion of Ringer's lactate solution at a rate of 100 mL/h. Adequacy of
randomization to the 2 treatment groups was assessed by comparing the patients'
relevant baseline history, physical examination, and symptoms. The predetermined
primary outcome measurement was the patient's sensation of "vertigo with
ambulation" 1 and 2 hours after treatment. Secondary outcome measurements
included vertigo while lying, sitting, and turning the head, ability to ambulate
as judged by the enrolling physician, and sensation of nausea and drowsiness 1
and 2 hours after treatment, and whether the patient was "ready to go home" per
patient report or physician assessment 2 hours after treatment. All patient
symptoms were reported on 10-point scales. Outcome measurements were compared
between the 2 treatment groups with a 2-way repeated-measures analysis of
variance, Student's t test, Mann-Whitney U, and chi(2) test as appropriate.
RESULTS: Ten patients refused entry into the study, 16 were excluded, and 74 were
enrolled, treated, and included in the analysis. One enrolled patient had
evidence of vertigo of central origin. The pretreatment values of vertigo with
ambulation were strongly correlated with the patient's ability to ambulate (P
<.001), suggesting good internal validity. The patients randomly assigned to the
lorazepam group were sicker based on their pretreatment symptoms and ability to
ambulate, and this may have biased the study results. The patients' symptom of
"vertigo with ambulation" decreased 1.5 units more (95% confidence interval [CI]
0 to 3.0) on average on a 10-point scale 2 hours after treatment in the
dimenhydrinate group. All other measures of vertigo also decreased more in the
dimenhydrinate group, although the differences were not statistically
significant. At 2 hours after treatment, the patients' ability to ambulate was
better in the dimenhydrinate group (P <.001), and 17% (95% CI -2 to 36) more
patients in this group were "ready to go home." Patients in the lorazepam group
experienced a 1.8-unit (95% CI 0.2 to 3.4) greater increase in drowsiness 2 hours
after treatment.
CONCLUSION: Our results suggest that dimenhydrinate was more effective in
relieving vertigo and less sedating than lorazepam at the intravenous doses
administered in this study. Dimenhydrinate appears to be the preferred medicine
for patients who present to the ED with vertigo likely to be of peripheral
origin.
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