tricyclic antidepressant-li”>374 Correspondence

References

1. Wu SH, Lynn JJ, Chan YL, Chiu TF, Chen JC, Chang YC. Acute Urinary retention as the initial manifestation of Guillain-Barre syndrome. Am J Emerg Med 2011;29(6):696.
2. Zochodne DW. Autonomic involvement in Guillain-Barre syndrome: a review. Muscle Nerve 1994;17:1145.
3. Hahn AF. Guillain-Barre syndrome. Lancet 1998;352(9128):635-41.
4. Ropper AH. The Guillain-Barre syndrome. N Engl J Med 1992;326 (17):1130-6.
5. Kono Y, Nishitarumizu K, Higashi T, Funakoshi K, Odaka M. Rapidly progressive Guillain-Barre syndrome following Escherichia coli infection. Intern Med 2007;46(9):589-91.

Incidence of tricyclic antidepressant-like complications after cyclobenzaprine overdose^?,??

To the Editor,

We thank the authors for their comments of our study. We agree that an ideal study of acute cyclobenzaprine toxicity would be prospective with blood levels, review of electro- cardiograms by 2 reviewers, and prospective collection of data from hospital records. Because this type of study is both expensive and it is difficult to find centers with sufficient cases, it is rarely performed. In lieu of this ideal study, we used a retrospective data set to evaluate a large volume of short-term cases as reported to several poison centers, a source of cases used to develop clinical guidelines [1].

We evaluated almost 4000 cases but focused on the most thoroughly documented 209 cases that had follow-up, had near certain ingestion by the specialist in poison information, and had therapies documented. We aimed to maintain rigorous methods for a retrospective study, and we listed several limitations including sample size and use of only poison center records [2]. In addition, our conclusion in the article qualified that this study includes only cases “reported to poison centers.” Finally, 2 cases received bicarbonate, but as we reported, no dysrhythmia or seizure was noted in the record. We may have missed serious effects from cyclobenzapr- ine; however, we detected several severe effects after tricyclic antidepressant ingestion (wide QRS, seizure, comma, hypotension, and death), which suggests that our approach

to recording clinical effects and treatments may be valid.

Although we did not detect a serious dysrhythmia in our study of 4000 cyclobenzaprine cases, it could occur. However, our results are congruent with a previous study of 402 cases over 5 years [3]. In addition, a credible case of wide complex dysrhythmia associated with cyclobenzaprine

^? Oral presentation at the Mediterranean Emergency Medicine Conference, March 2007.

has not been reported. Nonetheless, we welcome a prospective, multicenter study evaluating the clinical effects of acute cyclobenzaprine toxicity.

Vikhyat S. Bebarta MD Department of Emergency Medicine Wilford Hall Medical Center

San Antonio, TX 78261, USA E-mail address: [email protected]

Joseph Maddry MD San Antonio Uniformed Services Health Education Consortium Wilford Hall Medical Center San Antonio, TX, USA

E-mail address: [email protected]

Doug J. Borys RPh

Central Texas Poison Center

Temple, TX, USA E-mail address: [email protected]

David L. Morgan MD

Texas A & M University Health Science Center

College of Medicine Scott and White Hospital

Temple, TX, USA E-mail address: [email protected]

doi:10.1016/j.ajem.2011.09.005

References

1. Woolf AD, Erdman AR, Nelson LS, et al. Tricyclic antidepressant poisoning: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila) 2007;45(3):203-33.
2. Gilbert EH, Lowenstein SR, Koziol-McLain J, Barta DC, Steiner J. Chart reviews in emergency medicine research: where are the methods? Ann Emerg Med 1996;27(3):305-8.
3. Spiller HA, Winter ML, Mann KV, Borys DJ, Muir S, Krenzelok EP. Five-year multicenter retrospective review of cyclobenzaprine toxicity. J Emerg Med 1995;13(6):781-5.

Incidence of tricyclic antidepressant-like complications after cyclobenzaprine overdose^?

To the Editor,

Bebarta et al [1] commendably set out to determine whether patients who overdose on cyclobenzaprine are at risk for developing Tricyclic antidepressant (TCA)-like

^?? The authors have no financial support or financial interest in the

subject matter discussed. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the US Air Force, Department of Defense, or the US government.

^? Letter in response to Bebarta et al Incidence of tricyclic antidepres- sant-like complications after cyclobenzaprine overdose. American Journal of Emergency Medicine (2011) 29; 645-649.