Neuroleptic malignant syndrome during a change from haloperidol to risperidone

Atypical Neuroleptic Malignant Syndrome Associated with Use of Clozapine

The Neuroleptic Malignant Syndrome (NMS) is a medical emergency of infrequent presentation in the emergency department, which is associated with the use of psychiatric drugs, such as typical and atypical antipsychotics. Our case addresses a 55-year-old patient diagnosed with undifferentiated schizophrenia for 10 years, who had been receiving clozapine and clonazepam as part of their treatment. This patient presents the symptoms of Neuroleptic Malignant Syndrome without fever, which improves with treatment especially with the withdrawal of clozapine. In the absence of fever and clinical improvement, the patient is considered to have an atypical presentation of this disease.

Gabapentin-Induced Severe Myopathy

Objective:

To report and discuss a case of rhabdomyolysis in an elderly patient with neuropathic pain who was treated with gabapentin.

Case Summary:

An 85-year-old diabetic woman was hospitalized for severe pain in her lower limbs and difficulty in walking, compromising her daily activities. On admission, the woman's laboratory parameters, including creatine kinase (CK) and myoglobin, were in the normal range. Neurologic evaluation suggested a diagnosis of diabetic neuropathic pain, and therapy with gabapentin 150 mg 3 times daily was started. On the same day, the patient developed psychomotor agitation and gastric pain, which were treated with haloperidol 10 mg and lansoprazole 30 mg, respectively. In the following hours, the severity of muscular pain increased and the patient developed myopathy with acute renal failure (CK 459 U/L, myoglobin 11 437 ng/mL, creatinine 4.59 mg/dL), which worsened progressively during the next 2 days (CK 3095 U/L, myoglobin 17 000 mg/dL, creatinine 4.77 mg/dL) despite discontinuation of haloperidol and lansoprazole. No signs of trauma or edema, suggesting possible compartmental or crush syndrome, were detected. Gabapentin was then withdrawn and the patient's condition rapidly improved. Complete recovery followed in about 10 days.

Discussion:

Severe myopathy is an unexpected adverse reaction to gabapentin therapy. In this patient, a possible contribution of haloperidol or lansoprazole to the adverse event cannot be excluded. However, worsening of the clinical picture despite discontinuation of these drugs, together with rapid improvement observed after withdrawal of gabapentin, strongly suggest a causative role of gabapentin. According to the Naranjo probability scale, gabapentin was the probable cause of myopathy in this patient. The mechanism by which gabapentin may induce myopathy is unknown. The early onset of the syndrome after initiation of treatment with gabapentin in therapeutic doses is compatible with the picture of an idiosyncratic adverse response.

Conclusions:

Pathogenetic and clinical investigations are required to explore what mechanisms account for gabapentin-related muscular alterations at the time of onset, including electromyographic recordings as well as muscle and nerve histopathologic examinations. Until more information is available, clinicians should consider the possibility of discontinuing gabapentin treatment in patients showing muscular pain and signs of myopathy.

Association Between Selective Serotonin-Reuptake Inhibitors, Second-Generation Antipsychotics, and Neuroleptic Malignant Syndrome

Objective

To review the published reports of neuroleptic malignant syndrome (NMS) associated with the use of selective serotonin-reuptake inhibitors (SSRIs) and second-generation antipsychotics.

Data Source:

Information was selected from a MEDLINE search of English-language literature (1950–May 2008). Manual search of all published cases indexed in MEDLINE (English language only) of NMS associated with second-generation antipsychotics was also performed.

Study Selection And Data Extraction:

Pertinent information from all reports obtained was included, with specific emphasis on patient age, sex, second-generation antipsychotic involved, SSRI or other antidepressant involved, time of onset of NMS symptoms in relation to medication changes, treatment administered, and outcome of the reaction.

Data Synthesis:

NMS has been reported with every second-generation antipsychotic agent. It is unclear whether concomitant therapy with other agents may increase the risk of NMS development via pharmacodynamic or pharmacokinetic mechanisms or both, The suggested pharmacodynamic mechanism for increased risk of NMS with concomitant use of SSRIs is the effect of serotonin on dopamine release. Serotonin further inhibits dopamine release and thereby may worsen a hypodopaminergic state induced by antipsychotics. Pharmacokinetic factors may also play a role in some NMS cases involving an SSRI by increasing antipsychotic concentrations. An examination of case reports seems to indícale that at least in some casos, a temporal relationship exists with the addition of an SSRI to existing antipsychotic therapy.

Conclusions:

The use of SSRIs may be associated with an increased risk of NMS development in (hose receiving second-generation antipsychotics. Clinicians should closely monitor patients for the potential development of NMS.

Fatal neuroleptic malignant syndrome in a previously long-term user of clozapine following its reintroduction in combination with paroxetine

A 77-year-old patient with initial behavioral and psychological symptoms of dementia was treated with clozapine (50 mg/daily). Since no clinical benefit was apparent, clozapine was discontinued after six weeks and the patient started on paroxetine (20 mg/daily). After three weeks on paroxetine, he was given another trial of clozapine at a starting dosage of 25 mg/daily. While clozapine had previously been well tolerated, this time he rapidly developed fever, mental confusion, lethargy, muscle spasms and rigidity. The diagnosis of neuroleptic malignant syndrome was delayed, because there was no leukocytosis and serum creatine phosphokinase was initially not elevated. Subcutaneous apomorphine was then given but, after an initial improvement, the patient developed a multiple organ failure syndrome and died.

Neuroleptic malignant syndrome in an adolescent after brief exposure to olanzapine

A 17-year-old African-American male developed neuroleptic malignant syndrome (NMS) with hyperthermia, autonomic instability, increased muscle tone, rhabdomyolysis, and obtundation after a maximum of 2 days of treatment with olanzapine and 1 day of treatment with divalproex sodium. Intensive care unit (ICU)-level care was required. Paranoid psychosis with catatonia was present after recovery from the NMS. Because of his continued psychotic symptoms following resolution of the NMS, the alternate atypical antipsychotic, clozapine, was started under close observation. Reports of NMS resulting from atypical antipsychotic agents are generally uncommon, and much more so in the child and adolescent population. However, these agents are frequently prescribed in this population and require due caution.

The evaluation and management of patients with neuroleptic malignant syndrome

NMS is a rare but fatal syndrome that needs to be considered in the perioperative period. Although many aspects remain unexplored and controversial, with greater awareness of the condition, new concepts are coming into light. Definitive treatment guidelines remain an important issue to be addressed. Efforts have been initiated in that direction and all cases can be reported on a toll-free hotline ( 1-888-667-8367) or online (www.nmsis.org).

Neuroleptic malignant syndrome induced by atypical antipsychotics

A review of the English literature confirms that neuroleptic malignant syndrome (NMS) occurs with both traditional and atypical antipsychotic medications. Published reports of NMS induced by the traditional antipsychotics have given the practitioner valuable information on the prevention and treatment of this adverse effect. Case reports have also been published concerning NMS and clozapine, risperidone, olanzapine and quetiapine. By evaluating the case reports of atypical antipsychotic-induced NMS, valuable information may be obtained concerning similarities or differences from that induced by the traditional antipsychotics. The case reports of NMS with atypical antipsychotics were evaluated for diagnosis, age/sex of patient, risk factors, antipsychotic doses and duration of use, symptoms of NMS, and clinical course.