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Original Research Expression of Depressive Symptoms in a Nonclinical Brazilian Adolescent Sample
Clarice Gorenstein, PhD, Laura Andrade, MD, PhD, Elaine Zanolo, Rinaldo Artes, PhD
(PDF)

Posttraumatic Stress Disorder and General Psychopathology in Children and Adolescents Following a Wildfire Disaster
Brett M McDermott, MBBS, Cert Child Psych, FRANZCP, Erica M Lee, BA, Dip Psych, Marianne Judd, BSc Psych, MEd, Peter Gibbon, PhD
(PDF)

Individual Change in Methylphenidate Use in a National Sample of Children Aged 2 to 11 Years
Elisa Romano, PhD, Raymond H Baillargeon, PhD, Isabel Fortier, PhD, Hong-Xing Wu, MSc4, Philippe Robaey, MD, Mark Zoccolillo, MD, Richard E Tremblay, PhD
(PDF)

An Introduction to Economic Evaluation: What’s in a Name?
Jeffrey S Hoch, MA, PhD, Carolyn S Dewa, MPH, PhD
(PDF)

Recherche Originale *Méthadone et Syndrome d’Apnées du Sommeil
Philippe Durst, MD, Jérôme Palazzolo, MD, PhD, Jean-Pierre Peyrelong, MD, Michel Berger, MD, Michel Chalabreysse, MD, Michel Billiard, PhD, André Vialle, MD
(PDF)

Review Paper
Using Metaanalysis to Evaluate Evidence: Practical Tips and Traps
Raymond W Lam, MD, FRCPC, Sidney H Kennedy, MD, FRCPC
(PDF)

Brief Communication
Experimental Affective Symptoms in Panic Disorder Patients
Thea Overbeek, MD, PhD, Koen Schruers, MD, PhD, Ine Docters van Leeuwen, BSc, Tineke Klaassen, MD, PhD, Eric Griez, MA, MD, PhD
(PDF)

Book Reviews
(PDF)

The Treatment of Drinking
Problems: A Guide for the Helping Professions.
Review by
Nady el-Guebaly, MD, FRCPC

Bipolar Disorder: A Clinician’s Guide to Biological Treatments.
Review by
Review by: Rakesh Jain MD, MPH
Shailesh Jain, MD, MPH


Handbook of Female Psychopharmacology
Review by
Laura Calhoun, FRCPC

Sleep and Dreaming: Scientific Advances and Reconsiderations.
Review by
Alan Douglass, MD

Cognitive-Behavioral Treatment of Obesity. A Clinician’s Guide.
Review by
Hany Bissada, MD, FRCPC

Cognitive Therapy of Personality Disorders. Second Edition.
Review by
W John Livesley

Letters to the Editor
(PDF)

Hemorrhages During Escitalopram–Venlafaxine– Mirtazapine Combination Treatment of Depression

Re: Lorazepam-Induced Prolongation of the QT Interval in a Patient With Schizoaffective Disorder and Complete AV Block

Reply: Lorazepam-Induced Prolongation of the QT Interval in a Patient With Schizoaffective Disorder and Complete AV Block

Lithium-Associated Anencephaly

Aripiprazole-Induced Seizure

Prevalence of Bipolar Disorder and Major Depression Among Patients Seen in Primary and Secondary Care in Finland

The Need for More Community Nursing for Adults With Intellectual Disabilities and Mental Health Problems

Improvement in Tardive Dyskinesia With Aripiprazole Use

Letters to the Editor

Re: Lorazepam-Induced Prolongation of the QT Interval in a Patient With Schizoaffective Disorder and Complete AV Block

Dear Editor:

Dr Ziegenbein and Dr Kropp reported the case of a woman, aged 40 years, with schizoaffective disorder and a complete AV heart block, concluding that 3 dosages of lorazepam induced QT prolongation (1). The basis of their conclusion appears inexplicable.

The only argument for lorazepam as the putative agent appears to be that its use coincided with recognition of the QT abnormality. Electrolyte status was not reported. The QT prolongation persisted for 7 days after the discontinuation of lorazepam and all other psychotropic agents and required pacemaker placement. Even with the patient’s reported liver dysfunction (extent unknown), the lorazepam should have been cleared long before 7 days, owing to its half-life of 14 hours and lack of active metabolites (2). If lorazepam was responsible, the QT prolongation should have reversed. In addition, the patient was also receiving another benzodiazepine, diazepam. If lorazepam was responsible, it would need to have a unique mechanism of action—one that is distinct from the other benzodiazepines, which is not the case (2).

The more likely cause of this patient’s QT prolongation and, hence, her need for a pacemaker was her cardiovascular disease and complete AV block at admission. The patient’s liver dysfunction and diazepam prescription may also have potentiated the effects of the prescribed 2 antipsychotics (quetiapine and pipamperone) and tricyclic antidepressant (trimipramine) (2). The authors cite a study involving 495 psychiatric patients that found antipsychotics and tricyclic antidepressants, but not benzodiazepines, to be associated with QT prolongation (3). It is curious then that the authors would reach the conclusion they did, because it stands in opposition to the literature.

Therefore, to suggest that lorazepam-induced QT prolongation in the face of multiple confounding factors, lack of an expected time course, no obvious mechanism of action for the effect, and literature stating otherwise seems curious. Instead, the case should serve as an example of how, in complicated presentations, the coincidental timing of the onset of events can lead to misinterpreted causal associations. Clinicians should not change their practice with respect to lorazepam because of the cited case; this could potentially limit the drug’s appropriate use.

References

1. Ziegenbein M, Kropp S. Lorazepam-induced prolongation of the QT interval in a patient with schizoaffective disorder and complete AV block. Can J Psychiatry 2004;49:414.

2. Hardman JG, Limbird LE, Goodman Gilman A, editors. Goodman and Gilman’s the pharmacological basis of therapeutics. 10th ed. New York: McGraw-Hill; 2001.

3. Reilly JG, Ayis SA, Ferrier IN, Jones SJ, Thomas SHL. QTc-interval abnormalities and psychotropic drug therapy in psychiatric patients. Lancet 2000;355:1048–52.

David Crockford, MD, FRCPC
Calgary, Alberta