Neuroleptic Malignant Syndrome (NMS) is an idiosyncratic and
potentially life-threatening drug reaction. Although uncommon, NMS
cases induced by oral quetiapine have been reported. Most reports have
predisposing risk factors such as an organic brain disorder, concomitant
use of other antipsychotics or lithium, overdose or rapid titration. NMS
with low doses of quetiapine is a much rarer clinical picture. Venlafaxine
is commonly associated with withdrawal upon discontinuation
sometimes as soon as the next day. In this case report, a 40-year-old
man treated with venlafaxine for generalized anxiety disorder with
symptoms of full-blown NMS after venlafaxine withdrawal, induced
by low-dose quetiapine (50 mg), is presented. In accordance with
the previous reports, we speculate that venlafaxine withdrawal was a
predisposing factor in our case however we also discussed other possible
risk factors for NMS. Acknowledging the risk of NMS, even with
low doses of quetiapine in patients devoid of known risk factors, is of
paramount importance for prompt diagnosis and mitigating morbidity
and mortality. To our knowledge, this is the first case of NMS with
such a low dose of quetiapine without any other known risk factors or
substances.
Keywords: Antipsychotics, NMS, Quetiapine, Venlafaxine,
Consultation Liaison Psychiatry