For release: Wednesday, August 29, 2001
A new study shows that paramedics can safely and effectively treat patients who are suffering from acute and prolonged seizures with injections of benzodiazepines, a mild form of tranquilizers. In 59 percent of patients who received lorazepam, and in 43 percent of patients treated with diazepam, the seizures stopped before they arrived at the emergency department. Conversely, only 21 percent of patients in the placebo group arrived at the hospital seizure free.
The study is reported in the August 30, 2001 issue of The New England Journal of Medicine * by Daniel H. Lowenstein, M.D., now at Harvard Medical School in Boston, and formerly with the University of California at San Francisco, where the study took place. The lead author is Brian Alldredge, PharmD, UCSF professor of clinical pharmacy and clinical professor of neurology. The National Institute of Neurological Disorders and Stroke (NINDS) funded the research.
The study included 205 patients diagnosed with "status epilepticus," continuous or repeated seizures lasting 5 minutes or more without recovery of consciousness. Benzodiazepines are the drugs of choice for initial control of the prolonged type of seizures once the patients are in the hospital, but until now there has been no research evaluating the drugs' safety when they are delivered outside of the hospital.
The NEJM study reports that the odds that the patient's seizure would terminate by the time of admission to an emergency department were 4.8 times higher in the lorazepam group compared to the placebo group; 2.3 times higher in the diazepam group versus the placebo group; and 1.9 times higher in the lorazepam group compared to the diazepam group. Patients who received lorazepam also experienced shorter seizures than did the patients receiving diazepam or placebo.
The researchers also closely monitored respiratory and cardiovascular complications, which are common side effects of benzodiazepines. They reported complications in 11 percent of the lorazepam group, 10 percent of the diazepam group, but even higher, 23 percent, of the placebo group. The authors suggest that respiratory complications associated with prolonged seizures may be more pronounced than those caused by injection of the study drugs.
Although the differences between the two drugs were not statistically significant, the authors recommend lorazepam as the best prehospital treatment for patients in status epilepticus. However, they caution that lorazepam must be refrigerated, unlike diazepam.
"A patient who is in status epilepticus needs to be treated as quickly as possible in order to prevent serious neurological damage," said Audrey S. Penn, M.D., acting director of NINDS. "This study demonstrates that there is a safe and early treatment for a serious condition."
Despite the positive outcome of the study, the authors note that between 41 and 57 percent of patients were still in status epilepticus at the time of arrival at the emergency department and were twice as likely to require intensive care as those patients whose seizures ended earlier. Because of this, they recommend conducting future research with higher doses of lorazepam and diazepam to find the optimal therapy for these patients.
The NINDS is a component of the National Institutes of Health in Bethesda., Maryland and is the nation's primary supporter of biomedical research institute on the brain and nervous system. The Institute is celebrating its 50th anniversary this year.
*Alldredge, B.; Gelb, A.; Isaacs, S.M.; Corry, M; Allen, F.; Ulrich, SK; Gottwald, M.; O'Neil, N.; Neuhaus, J.; Segal, M.; Lowenstein, D. "A Comparison of Lorazepam, Diazepam and Placebo for Treatment of Out-of-Hospital Status Epilepticus." The New England Journal of Medicine , Volume 345, Issue 9, Aug. 30, 2001.
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Last Modified April 8, 2013