Escitalopram causes fewer seizures in human overdose than citalopram.
BACKGROUND
Seizures are a recognized complication of acute overdose with the racemic (1:1 ratio of R- and S-enantiomers) selective serotonin reuptake inhibitor antidepressant citalopram.


OBJECTIVE
We tested the hypothesis that escitalopram (the therapeutically active S-enantiomer of citalopram) causes fewer seizures in overdose than citalopram at comparable doses of the S-enantiomer.


METHODS
Multicenter retrospective review of cases with citalopram and escitalopram overdose reported to German, Austrian, and Swiss Poisons Centers between 1997 and 2006.


RESULTS
316 citalopram and 63 escitalopram cases were analyzed. Somnolence, nausea, vomiting, tachycardia, QT prolongation, and tremor occurred with similar frequency in both groups. There was a striking difference in the frequency of single and multiple seizures: 43 cases (13.5%) in the citalopram group and 1 case (1.6%) with a single seizure in the escitalopram group (p=0.0065).


CONCLUSIONS
At comparable ingested doses of the S-enantiomer, the symptom profile for citalopram and escitalopram intoxications is similar except for seizures that occur more frequently in citalopram than in escitalopram poisoning.
Yilmaz
Zeynep
Z
Swiss Toxicological Information Centre, Zurich, Switzerland.
Ceschi
Alessandro
A
Rauber-Lüthy
Christine
C
Sauer
Oliver
O
Stedtler
Uwe
U
Prasa
Dagmar
D
Seidel
Carola
C
Hackl
Elisabeth
E
Hoffmann-Walbeck
Petra
P
Gerber-Zupan
Gabriela
G
Bauer
Kathrin
K
Kupferschmidt
Hugo
H
Kullak-Ublick
Gerd-Achim
GA
Wilks
Martin
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001317:Austria; D015283:Citalopram / Q000737:chemistry / Q000506:poisoning*; D062787:Drug Overdose; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D011039:Poison Control Centers / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012640:Seizures / Q000139:chemically induced*; D017367:Selective Serotonin Reuptake Inhibitors / Q000737:chemistry / Q000506:poisoning*; D013237:Stereoisomerism; D013557:Switzerland; D055815:Young Adult
D015283:Citalopram; D017367:Selective Serotonin Reuptake Inhibitors