QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Résumé Extracto Full Text PDF Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Articles Ahead of Print [Order Reprint] Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sattar, S P. Articles by Petty, F. Search for Related Content PubMed PubMed Citation Articles by Sattar, S P. Articles by Petty, F.

Somnambulism Due to Probable Interaction of Valproic Acid and Zolpidem

Assistant Professor of Psychiatry, Department of Psychiatry, School of Medicine, Creighton University; Associate Director of Residency Training, Omaha Veterans Affairs Medical Center, Omaha, NE

Sriram Ramaswamy, MD

PGYIII Psychiatry Resident, Creighton University/University of Nebraska, Omaha

Subhash C Bhatia, MD

Professor of Psychiatry and Vice Chair, School of Medicine, Creighton University; Chief, Department of Mental Health and Behavioral Science, Omaha Veterans Affairs Medical Center

Frederick Petty, PhD MD

Professor of Psychiatry and Vice Chair for Research, School of Medicine, Creighton University; Associate Chief, Department of Mental Health and Behavioral Science, Omaha Veterans Affairs Medical Center

Reprints: S Pirzada Sattar MD, Omaha Veterans Affairs Medical Center, 4101 Woolworth Ave., 116A, Omaha, NE 68105-1850, FAX 402/943-5540, syed.sattar{at}med.va.gov

OBJECTIVE: To report a case of somnambulism due to a probable interaction between valproic acid and zolpidem in a patient with no prior personal or family history of somnambulism.

CASE SUMMARY: A 47-year-old white man with a history of bipolar disorder was being maintained on citalopram 40 mg once daily and zolpidem 5 mg at bedtime. During treatment, he developed manic symptoms and was started on adjunctive valproic acid therapy. Soon after this, he developed episodes of somnambulism, which stopped when valproic acid was discontinued. On rechallenge with valproic acid, somnambulism returned.

DISCUSSION: To our knowledge, this is the first report in the literature describing a probable interaction between valproic acid and zolpidem leading to somnambulism. Even though valproic acid has been associated with sleep changes, there are no published reports of somnambulism with this agent. Zolpidem has been associated with somnambulism, but our patient did not experience this when he was on zolpidem monotherapy. However, within 2 days of starting adjunctive valproic acid, sleepwalking occurred. It stopped after valproic acid was withdrawn. On rechallenge with valproic acid, sleepwalking recurred. However, when zolpidem was discontinued and valproic acid was continued, somnambulism did not occur. An assessment on the Naranjo probability scale suggests probable pharmacokinetic or pharmacodynamic interactions between the 2 medications.

CONCLUSIONS: Valproic acid and zolpidem are generally safe medications that are commonly prescribed and often used together. No interactions have been previously reported with combined use of valproic acid and zolpidem. This case suggests a probable interaction between these 2 agents that can have a serious consequence, somnambulism. This could be frightening to patients and put them in danger. Recognition of such interactions that place patients at risk for potentially serious adverse events is imperative for appropriate care.

Key Words: somnambulism, valproic acid, zolpidem

Published Online, August 15, 2003. www.theannals.com, DOI 10.1345/aph.1C500