Related Experiment Video

Updated: Jun 23, 2026

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
07:35

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale

Published on: July 8, 2025

Neuroleptic malignant syndrome induced by atypical neuroleptics and responsive to lorazepam

Adeeb Yacoub1, Andrew Francis

  • 1Department of Psychiatry and Behavioral Science, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY, USA.

Neuropsychiatric Disease and Treatment
|May 5, 2009
PubMed
Abstract

Insights

Atypical antipsychotics like olanzapine and clozapine can cause neuroleptic malignant syndrome (NMS), presenting with rigidity and fever. Early intervention with lorazepam and supportive care aids recovery from NMS.

Area of Science:

  • Neuroscience
  • Pharmacology
  • Clinical Medicine

Background:

  • Neuroleptic malignant syndrome (NMS) is a rare but serious adverse reaction to antipsychotic medications.
  • Atypical antipsychotics are increasingly used, necessitating an understanding of their associated risks.

Observation:

  • Three case reports detail patients developing NMS while on atypical antipsychotics (olanzapine, clozapine).
  • Clinical presentation included classic NMS features: muscular rigidity and prominent fever.
  • Onset varied, occurring within 6 to 14 days of initiating clozapine or olanzapine therapy.

Findings:

  • Discontinuation of the offending neuroleptic, supportive care, and administration of lorazepam led to resolution of NMS symptoms within 72 hours.
  • The Neuroleptic Malignant Syndrome rating scale demonstrated sensitivity to daily clinical improvement.
  • Lorazepam may expedite recovery from NMS induced by atypical antipsychotics, similar to its effect with typical antipsychotics.

Implications:

  • Clinicians should be vigilant for NMS when prescribing atypical antipsychotics.
  • Prompt recognition and management, including lorazepam, can improve patient outcomes.
  • Further research into the role of lorazepam in atypical antipsychotic-induced NMS is warranted.
Keywords:
atypical antipsychoticscatatonialorazepamneuroleptic malignant syndromerating scale

Related Concept Videos

Psychosis: Goals of Pharmacotherapy01:26

Psychosis: Goals of Pharmacotherapy

Antipsychotic drugs are a crucial treatment method for acute and chronic psychoses, bipolar illness, and behavioral disorders. The selection of these drugs depends on several factors, including the state of the disease, clinical judgment, possible drug interactions, and the patient's sensitivity to adverse effects. In immediate scenarios, such as delirium and dementia, short-term treatment with low doses of high-potency typical or atypical agents can effectively manage symptom exacerbation. For...
Antipsychotic Drugs: Typical and Atypical Agents01:21

Antipsychotic Drugs: Typical and Atypical Agents

Antipsychotic drugs are classified into first-generation (typical) drugs including phenothiazines; and second-generation (atypical) drugs. Chlorpromazine hydrochloride (Thorazine), a phenothiazine derivative, broadly impacts the central, autonomic, and endocrine systems. This drug, along with typical agents like haloperidol (Haldol), primarily works by antagonizing D2 receptors, thus reducing dopaminergic neurotransmission. However, typical antipsychotics can cause side effects such as sedation...
Mania and Antimanic Drugs: Overview01:24

Mania and Antimanic Drugs: Overview

Mania, a psychological condition characterized by elevated mood, increased energy, and reduced sleep need, is part of the bipolar disorder cycle. The exact cause of mania isn't entirely known, but it is thought to be a combination of genetic, environmental, and neurological factors. Bipolar disorder involves alternating manic and depressive episodes. Mood stabilizers like lithium, antipsychotics, and anticonvulsants help manage these episodes. Lithium carbonate is particularly effective as a...
Psychosis and Antipsychotic Drugs: Overview01:28

Psychosis and Antipsychotic Drugs: Overview

The term "psychosis" refers to a spectrum of mental disorders characterized by abnormal thoughts, perceptions, and behaviors. It can manifest as mood disorders, dementia, delirium with psychotic features, substance-induced psychosis with psychotic features, brief psychotic disorder, delusional disorder, schizoaffective disorder, and schizophrenia. Among all these disorders, schizophrenia is the most common psychotic disorder, affecting 1% of the worldwide population. Psychotic symptoms in all...
Antipsychotic Drugs: Therapeutic Uses and Side Effects01:21

Antipsychotic Drugs: Therapeutic Uses and Side Effects

Antipsychotic drugs primarily block dopamine and serotonin receptors and cholinergic, adrenergic, and histaminergic receptors, thereby reducing hallucinations and delusions in conditions like schizophrenia. However, they can trigger unwanted extrapyramidal effects such as dystonias, Parkinson-like symptoms, and tardive dyskinesia.
Despite these side effects, antipsychotics are used therapeutically for various purposes, including managing schizophrenia, preventing nausea and vomiting, curbing...
Restless Leg Syndrome and Night Terrors01:27

Restless Leg Syndrome and Night Terrors

Restless Leg Syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder characterized by an uncontrollable urge to move the legs due to uncomfortable sensations. These sensations typically occur during periods of rest or inactivity, particularly when lying down or sitting, and can severely disrupt sleep.
The exact cause of RLS is not fully understood, but it is believed to involve dopamine, a neurotransmitter that helps regulate muscle movement. Imbalances in dopamine levels...