Letters to the Editor
Quetiapine and Neuroleptic Malignant Syndrome
Dear Editor:
Neuroleptic malignant syndrome (NMS) is a reported complication of treatment
with the atypical neuroleptics clozapine, risperidone, and olanzapine (1,2).
I report a case of NMS associated with quetiapine as the sole neuroleptic.
Case Report
Mr AB is a reclusive, single, white man aged 44 years. His initial paranoid
psychotic symptoms began 19 years previously, during multimodal therapy
for stage 3A Hodgkin’s disease. For 3 years, he had been stable in the
community on risperidone 4 mg daily, followed by olanzapine 20 mg daily
for over 1 year prior to this episode. Six months before this admission,
his olanzapine 20 mg daily was gradually tapered, with a view to his entering
a ziprasidone trial. At 10 mg olanzapine his psychosis relapsed, and he
was restabilized in hospital on quetiapine 400 mg and clonazepam 2.5 mg
daily. Eight weeks after starting quetiapine, he suddenly and rapidly decompensated,
displaying increased paranoia, loosened associations, and disorganized
thinking and behaviour. On return to hospital, he had a temperature of
38.4ºC, a fluctuating blood pressure as high as 160/110, and a rapid, regular
pulse rate of up to 140 beats per minute. He maintained postures, his muscle
tone was only minimally increased, and his creatine phosphokinase (CPK)
was elevated to 1613 IU/litre. His attention was impaired, and his sparse
verbal output was grossly disordered, exhibiting grandiose and paranoid
themes. He was extensively investigated for a fever of unknown origin.
Aside from an elevated white cell count of 15.9 x 109/litre and CPK levels
that peaked at 3485 IU/litre, the remaining results were all within the
normal limits. He was treated for NMS with rehydration and dantrolene until
his fever, pulse, blood pressure, and CPK settled 3 weeks later. His CPK
fell to below 1000 IU/litre within 3 days of discontinuing quetiapine and
took another 2 weeks to normalize.
Since he remained mute, disorganized, incontinent of urine, and severely
psychotic, he was transferred back to psychiatry. When treated with a course
of unilateral electroconvulsive therapy, he improved after the first treatment,
becoming more communicative and organized. He recovered after 7 treatments
and was restarted on olanzapine 10 mg daily. He was discharged for outpatient
follow-up and 1 year later remains well and stable in the community.
NMS has been reported as a rare complication of treatment with clozapine,
risperidone (1), and most recently, olanzapine (2). Quetiapine is a novel
dibenzothiazepene clozapine–like neuroleptic with fewer D2-blocking properties
than clozapine (3). It has a correspondingly low propensity to induce extrapyramidal
side effects (EPS) (4). There are 3 reports of possible NMS associated
with quetiapine, 1 case of which occurred with concomitant use of loxapine
(5), 1 with concomitant use of sulpiride (6), and 1 in which quetiapine
was the sole antipsychotic (7). The NMS picture that occurs with atypical
antipsychotic agents may be milder than that which occurs with typical
agents (8) and corresponds to 2 of the reported cases involving quetiapine
(6,7). This patient had mild physical manifestations and more prominent
mental status changes. Despite quetiapine’s low propensity to cause EPS,
NMS needs to be considered in the differential of patients on quetiapine
who present with NMS-like features.
References
1. Hasan S, Buckley P. Novel antipsychotics and the neuroleptic malignant
syndrome: a review and critique. Am J Psychiatry 1998;155:1113–6.
2. Gheorghiu S, Knobler H, Drumer D. Recurrence of neuroleptic malignant
syndrome with olanzapine treatment. Am J Psychiatry 1999;156:1836–7.
3. Gefvert O, Bergstrom M, Langstrom B, Lundberg T, Lindstrom L, Yates
R. Time course of central nervous dopamine-D2 and 5HT2 receptor blockade
and plasma concentrations after discontinuation of quetiapine (Seroquel)
in patients with schizophrenia. Psychopharmacology 1998;135:119–26.
4. Targum SD, Arvantis LA. Quetiapine: efficacy, safety, and tolerability
in elderly subject with psychotic disorders. Psychopharmacology Bulletin
1997;33:596.
5. Al-Waneen R. Neuroleptic malignant syndrome associated with quetiapine
[letter]. Can J Psychiatry 2000;45:764.
6. Stanley AK, Hunter J. Possible neuroleptic malignant syndrome with quetiapine.
Br J Psychiatry 2000;176:497.
7. Whalley N, Diaz P, Howard J. Neuroleptic malignant syndrome associated
with the use of quetiapine. Can J Hospital Pharmacy 1999;52:112.
8. Sachdev P, Kruk J, Kneebone M, Kissane D. Clozapine-induced neuroleptic
malignant syndrome: review and report of new cases. J Clin Psychopharmacol
1995;15:365–71.
Kevin Solomons, MD, FRCPC
Vancouver, British Columbia
|
