Severe rhabdomyolysis following a viral illness: a case report and review of the literature

Rhabdomyolysis: A Case Report of an Extrapulmonary Presentation of Mycoplasma pneumoniae

Introduction

We present an unusual case of rhabdomyolysis secondary to Mycoplasma pneumoniae in a healthy 27-year-old female. M. pneumoniae is associated with numerous extrapulmonary manifestations, including acute hepatitis, Stevens-Johnson syndrome, and rhabdomyolysis. Most documented cases affect the pediatric population, with only five cases in adults reported in the literature.

Case Report

The patient presented with complaints of myalgia and intractable cough. In this case the initial presentation demonstrated hypoxia requiring supplemental oxygen, and a creatine kinase of 7,646 units per liter (U/L) (reference range 26–192 U/L) with a peak of 29,427. During her hospitalization, she also remained persistently hypoxic for several days but ultimately was successfully weaned off all supplemental oxygen. She was discharged home after a seven-day hospitalization.

Conclusion

This patient’s presentation of an insidious, upper respiratory infection along with the subsequent development of rhabdomyolysis with reactive antibodies to M. pneumoniae demonstrates a link between these two clinically important conditions.

Acute rhabdomyolysis in a young woman with moderate COVID-19

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COVID-19-associated rhabdomyolysis is most common in older men with severe disease.

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This case of rhabdomyolysis occurred in a young woman with moderate COVID-19.

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She practiced daily strength training, which may have increased her risk.

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She was treated with intravenous fluid infusion, dexamethasone, and remdesivir.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is having serious medical, social, and economic impacts worldwide. COVID-19 may lead to a variety of complications, including rhabdomyolysis. Although rhabdomyolysis is a rare complication, it can lead to severe kidney damage. Recent studies suggest that rhabdomyolysis caused by SARS-CoV-2 is more common in middle-aged and older men with severe COVID-19. Herein we report a case of rhabdomyolysis in a young woman with moderate COVID-19. She had a habit of muscle training. She presented with moderate COVID-19 and acute rhabdomyolysis that required a large volume of fluid infusion in addition to dexamethasone and remdesivir. Clinicians should pay attention to the development of rhabdomyolysis in patients with COVID-19, especially those with a habit of strenuous exercise or muscle training, even if they are young and have moderate COVID-19.

Acute viral myositis: profound rhabdomyolysis without acute kidney injury

Background

Acute viral myositis (AVM) may be triggered by influenza A/B, enteroviruses and other viruses. Severe complications including rhabdomyolysis regularly lead to acute kidney injury (AKI). The aim of this short report was to discuss management and differential diagnosis of massive creatine kinase (CK) elevation.

Patient, material and methods

Herein, we report on a 19-year-old Austrian male of African descent with a history of respiratory tract infections and whole-body pain. He further developed acute viral myositis and massive CK elevation up to 440,000 IU/L but without any signs of AKI. A literature search relating AVM, management and differential diagnosis of rhabdomyolysis was conducted in PubMed and UptoDate.

Results

A full panel of serological and autoimmune blood work-up including testing for human immunodeficiency virus (HIV), hepatitis, influenza A/B, Epstein-Barr virus (EBV), antinuclear antibodies (ANA) and autoantibodies against various extractable nuclear antigens (ENA) did not reveal evidence for viral originators or autoimmune diseases. This case indicates that in acute viral myositis associated with extreme CK elevation (>400,000 IU/L) AKI might be completely absent. Potential causes for this clinical phenotype, differential diagnosis and management are discussed.

SARS-CoV-2 infection complicated with cold agglutinin disease and myositis

This case emphasizes the importance of prompt comprehensive investigation of anemia and myositis in patients infected with SARS-CoV-2 and early recognition of uncommon complications that can be associated with SARS-CoV-2 infection.

Weakness and elevated creatinine kinase as the initial presentation of coronavirus disease 2019 (COVID-19)

COVID-19 is a global public health emergency with more than one million positive cases across the globe. COVID-19 has a multifaceted presentation. We are herein to report two cases of SARS-CoV-2 induced rhabdomyolysis with an initial presentation of weakness and elevated creatinine kinase (CK). Both patients had no respiratory symptoms, they only complained of generalized weakness and were found to have elevated CK. Routine chest X-ray showed bilateral infiltrates in both cases and subsequently reverse-transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 was positive. To the best of our knowledge, there was only one literature to date documented SARS-CoV-2 induced rhabdomyolysis as a late complication of COVID-19 patient. Our cases showed that elevated CK and rhabdomyolysis can be the sole initial presentation of patients with COVID-19 and total CK should be ordered in every patient on admission.

Echovirus 30 detection in an outbreak of acute myalgia and rhabdomyolysis, Brazil 2016-2017

OBJECTIVES

To describe an outbreak of acute myalgia accompanied by elevated levels of muscle enzymes that occurred in the northeast region of Brazil from December 2016 through to May 2017.

METHODS

Clinical data were analysed and laboratory tests were performed in 86 specimens obtained from 52 individuals with suspected acute myalgia. A broader reactive enterovirus real-time RT-PCR followed by a semi-nested PCR amplification of partial VP1 gene were performed to identify the causative agent.

RESULTS

Eighty-six clinical samples were received in our laboratory during the myalgia outbreak. Median age of individuals was 39 years. Sudden acute myalgia and dark urine were the most common symptoms. Creatine phosphokinase levels were elevated with mean value ∼16 893 U/L. Human enterovirus was detected in 67% (58/86) of the patient's specimens (urine, serum, faeces and rectal swab). The enterovirus positivity per patient was 82.7% (43/52). Echovirus 30 (E-30) (82% of the typed specimens, 18/22; 76.4% (13/17) of the typed specimens per patient) was the main enterovirus identified. In addition to E-30, CV-A16 (1/22) and E-6 (3/22) were detected in 4% and 14% of the typed specimens, respectively. No deaths occurred.

CONCLUSION

The 2016-2017 outbreak of acute myalgia that occurred in the northeast region of Brazil can be associated with E-30. Despite the clinical manifestations, a favourable outcome was observed for all patients.

Rhabdomyolysis: An Unusual Presentation of Mycoplasma pneumoniae Infection in an Adult-A Case Report and Literature Review

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia, and many extrapulmonary manifestations have been described, but rhabdomyolysis is infrequently reported in adults. Of the few cases that have been reported in adults, it was almost exclusively seen when pneumonia was present. We report a case of a 30-year-old male who came in with complaints of fever and myalgia for three days. Immunoglobulin M antibodies for Mycoplasma pneumoniae were positive and trending up, despite having no radiographic evidence of pneumonia on chest X-ray or CT scan. He was treated successfully with levofloxacin and intravenous hydration. Later, his condition was clinically and biochemically improved, and he was discharged. Our patient did not present with typical respiratory tract symptoms of a mycoplasma infection. In addition, there was an absence of pneumonia on imaging, suggesting that rhabdomyolysis secondary to mycoplasma might be underdiagnosed and go untreated in the setting of low clinical suspicion. Upon review of the literature, there is only one other case of mycoplasma infection where rhabdomyolysis occurred in the absence of pneumonia. However, the degree of rhabdomyolysis in our case was much more severe. Although rare, when faced with rhabdomyolysis, Mycoplasma pneumoniae should be kept as a differential diagnosis even in the absence of pneumonia on radiological imaging.

Rhabdomyolysis secondary to systemic lupus erythematosus

Systemic lupus erythematous (SLE) is a systemic auto-immune disorder with a variety of presentations and wide spread organ involvement. We present a case report of a patient with an SLE exacerbation as well as concurrent rhabdomyolysis with massively elevated CPK (304,700 U/L). Though a rarely reported effect of SLE, rhabdomyolysis can be severe and potentially lethal secondary or concurrent to an acute SLE episode. This case report demonstrates the association between SLE and rhabdomyolysis, which is not well described in the current literature.

Post-vaccination myositis and myocarditis in a previously healthy male

Background

The immunological literature has been redefining clinical phenomena as hypotheses emerge regarding causal links between triggers, immunologic manifestations, and their specific inflammatory cascades. Of late, autoimmune manifestations that appear to be caused by an external adjuvant have been grouped into a complex syndrome referred to as autoimmune/inflammatory syndrome induced by adjuvants (ASIA). This syndrome may present with diverse clinical problems, which may include neurocognitive impairment, inflammatory musculoskeletal changes, and constitutional symptoms. There is evidence in the literature linking vaccines to different auto-immune manifestations. Vaccines have not traditionally been reported to trigger ASIA, although reports are emerging linking the human papilloma virus and hepatitis B vaccines to it.

Case presentation

We report the first suspected case of ASIA in a previously healthy patient who received the Fluad seasonal influenza vaccine, which contains the MF59 adjuvant. He presented to hospital with profound weakness and was diagnosed with severe rhabdomyolysis. He also had elevated troponin-I and extensive cardiac investigations enabled the diagnosis of myocarditis. His infectious and rheumatologic work-ups were negative. He responded well to conservative management and did not require immune suppressive therapy.

Conclusion

Given the benefits of the influenza vaccine, and the low incidence of clinically significant complications, we encourage ongoing seasonal influenza immunization. However, ongoing surveillance is required to evaluate the occurrence of rare adverse events, including ASIA.

Rhabdomyolysis Caused by Candida parapsilosis in a Patient with Acute Myeloid Leukemia after Bone Marrow Transplantation

Rhabdomyolysis is characterized by a marked elevation of the creatine kinase (CK) levels and myoglobinuria, thus leading to renal dysfunction. Various viruses or bacteria can be etiologic agents, but mycosis has only rarely been reported to be a cause of rhabdomyolysis. In this report, we describe an adolescent male with acute myeloid leukemia who underwent allogeneic bone marrow transplantation and thereafter developed rhabdomyolysis and Candida parapsilosis fungemia almost at the same time. Following treatment for C. parapsilosis, the transaminase and CK levels both satisfactorily decreased. This case illustrates that C. parapsilosis infection may be a causative agent of rhabdomyolysis in immunocompromised patients.

Clinical features of and risk factors for rhabdomyolysis among adult patients with dengue virus infection

Among 1,076 dengue patients, 9 patients with rhabdomyolysis and 1,067 patients without rhabdomyolysis (controls) were retrospectively analyzed. Of nine patients with rhabdomyolysis, the most commonly reported symptom other than fever was myalgia; dengue hemorrhagic fever (DHF) was found in seven cases, and acute kidney injury was found in six cases. Furthermore, one (11.1%) patient died. The median duration from hospital admission to rhabdomyolysis diagnosis was 3 days. Patients with rhabdomyolysis had higher age, proportion of men, prevalence of hypertension, frequency of myalgia, and incidences of DHF, pleural effusion, and acute kidney injury than controls. Multivariate analysis showed that hypertension (odds ratio [OR] = 14.270), myalgia (OR = 20.377), and acute kidney injury (OR = 65.547) were independent risk factors for rhabdomyolysis. Comparison of cytokine/chemokine concentrations in 101 DHF patients, including those with (N = 4) and without (N = 97) rhabdomyolysis, showed that interleukin-6 and tumor necrosis factor-α levels were significantly increased in the former.

Clinical spectrum of rhabdomyolysis presented to pediatric emergency department

BACKGROUND

Rhabdomyolysis is a potentially life-threatening syndrome that can develop from a variety of causes. The aim of the work is to analyze the clinical spectrum and to evaluate the prevalence of various etiologies in children, who present to the emergency department (ED) with rhabdomyolysis.

METHODS

During a 6-year study period, we retrospectively analyzed the medical charts of patients, aged 18 years or younger, with a definite diagnosis of rhabdomyolysis and serum creatinine phosphokinase (CK) levels greater than 1000IU/L. We analyzed the clinical spectrum and evaluated the potential risk factors of acute renal failure (ARF).

RESULTS

Thirty-seven patients (mean age = 10.2 ± 5.5 years), including 26 males and 11 females, were enrolled in the study. Two of the most common presented symptoms in these 37 patients were muscle pain and muscle weakness (83.8% and 73%, respectively). Dark urine was reported in only 5.4% of the patients. The leading cause of rhabdomyolysis in the 0- to 9-year age group was presumed infection, and the leading cause in the 10- to 18-year age group was trauma and exercise. The incidence of ARF associated with rhabdomyolysis was 8.1 % and no child needed for renal replacement therapy (RRT). We did not identify any reliable predictors of ARF or need for RRT.

CONCLUSIONS

The classic triad of symptoms of rhabdomyolysis includes myalgia, weakness and dark urine are not always presented in children. The cause of rhabdomyolysis in younger age is different from that of teenager group. However, the prognosis of rhabdomyolysis was good with appropriate management.

A potentially life-threatening complication of university orientation activities

BACKGROUND

This case report describes a university student who participated in an orientation activity and developed exertional rhabdomyolysis.

METHODS

With prompt intravenous volume expansion started in the accident and emergency department, he made an uneventful recovery despite a marked elevation of creatine kinase. The riskfactors of developing exertional rhabdomyolysis were reviewed. Suggestions based on these risk factors were made to the organizers of such orientation programmes.

RESULTS

He was discharged on day 6. On follow-up on day 8 after presentation at theaccident and emergency department, the CK level was 46 000 U/L and it fell to 2600 U/L in another 2 weeks. On follow-up 3 weeks after the incident, he remained well without symptoms.

CONCLUSION

For the clinicians, once rhadbomyolysis is suspected or diagnosed, intravenous fluid therapy with a crystalloid should be initiated as soon as possible to prevent the occurrence of acute renal faiure.

Influenza B-associated rhabdomyolysis in Taiwanese children

AIM

Influenza B-associated rhabdomyolysis (IBAR) is an infrequent and little-known complication of influenza B virus infection in children. Diagnosis is usually made based on clinical history, the presence of influenza in the community and detection of virus in nasopharyngeal specimens. The aim of this study was to describe the clinical and laboratory manifestations, complications and outcomes of IBAR in Taiwanese children.

METHODS

A retrospective analysis was conducted in patients aged < 17 years who had been diagnosed with IBAR at a university children's hospital in North Taiwan during 2000-2007. All children enrolled in the study had presented with rhabdomyolysis associated with laboratory-confirmed influenza B infections. Demographic data, clinical manifestations, complications and outcomes were included in the analysis.

RESULTS

Overall, 24 IBAR cases were analysed. IBAR typically occurred in school-aged children with a 7:3 male:female ratio. The mean age was 7.2 ± 1.9 years. Nearly 63% of cases occurred between the ages of 6 and 9 years. The median interval between the onset of influenza and onset of IBAR was 3.4 days (range, 1-14). The calf muscles were involved in all cases. Laboratory tests indicated a mean initial blood creatine kinase of 4212 U/L. The median time to clinical recovery was 5 days (range 1-24). No patient had renal failure. IBAR tends to occur mainly in winter and spring during influenza B outbreaks. IBAR sometimes induces some complications, and early detection and careful medical treatment are necessary.

CONCLUSION

The results of this study indicate that outcomes of IBAR are good with proper medical care.

Clinical and laboratory analysis of influenza B infection in children in Taichung, Taiwan during the 2006-2007 flu season

BACKGROUND

An epidemic of influenza B/Malaysia/2506/2004 was reported in Taiwan during the 2006-2007 flu season. We investigated the flu vaccination history and clinical and Laboratory characteristics of children with influenza B infection.

METHODS

We enrolled children younger than 18 years old who visited one of two hospitals between November 2006 and February 2007 with influenza-like illnesses. Throat swabs were taken on their first visit and cultured for viruses. Complete and differential blood counts and blood biochemical parameters were analyzed in some children.

RESULTS

Influenza virus was cultured from 51.0% of patients (101/198), 87 (86.1%) of who were infected with influenza virus type B. The remaining 14 (13.9%) were infected with influenza virus type AH3. The 87 children (median age 7.8 years) with culture-proven influenza B virus infection were enrolled. Nine parents reported that enrolled children had been vaccinated against influenza. Leukopenia was found in 56.1% (32/57) of patients, leukocytosis in 3.5% (2/57), and thrombocytopenia in 1.8% (1/57). Thirteen of 23 patients (56%) tested for creatine kinase (CK) had elevated levels ( >160 U/L), and 11 of 23 (47.8%) had myalgia associated with raised CK (p < 0.05). Twenty-six children developed complications, including one case of pneumonia with acute respiratory distress syndrome and one case of flu-associated encephalitis.

CONCLUSION

Most children who contracted influenza B infection had not been vaccinated. Almost half the children had leukopenia, and some had leukocytosis, but thrombocytopenia was rare. There was a significant association between raised CK levels and myalgia in influenza B infection.

Rhabdomyolysis and acute renal failure associated with influenza virus type B infection

A patient with rhabdomyolysis-induced acute renal failure due to influenza B virus infection is presented. Influenza B infection caused rhabdomyolysis with efflux of myoglobin from myocytes, causing acute renal failure. In conclusion, influenza virus type B can cause severe rhabdomyolysis leading to acute renal failure.

Acute myopathy associated with liver cirrhosis

AIM: Many cirrhotic patients have muscular symptoms and rhabdomyolysis. However, myopathy associated with liver cirrhosis has not been established as a disease entity. We evaluated the clinical significance of acute myopathy associated with liver cirrhosis.

METHODS: We retrospectively reviewed the medical records of 5 440 cirrhotic patients who had been admitted to Gyeongsang National University Hospital from August 1997 to January 2003. Among these, 99 developed acute myopathies, and they were analyzed with respect to clinical and laboratory parameters, and outcomes.

RESULTS: The Child-Pugh classification at the time of myopathy onset was A in 3(3.1%) cases, B in 33(33.3%), and C in 63 (63.6%). Infection was identified as the most predisposing factor to myopathy. Fifty percent of 18 idiopathic cases who were tested for influenza antibody were positive. Forty-two of the 99 cases were complicated by acute renal failure, and 25 (59.5%) of these expired. Apart from 6 cases lost to follow-up, 64 of 93 recovered, giving a mortality rate of 31.2%. Mortality was higher in Child-Pugh class C than in B or A.

CONCLUSION: Acute myopathy can develop as a serious complication in liver cirrhosis. Its frequency, severity and mortality depend on underlying liver function, and are higher in decompensated liver cirrhosis. Influenza should be considered as an etiologic factor in idiopathic cases. It is proposed that acute myopathy associated with liver cirrhosis be called ‘hepatic myopathy’, and that careful monitoring for hepatic myopathy is necessary in the patients with advanced liver cirrhosis.

Rhabdomyolysis in patients with west nile encephalitis and meningitis

Since 1999, more than 6,500 cases of West Nile virus neuroinvasive disease (WNND) have been reported in the United States. Patients with WNND can present with muscle weakness that is often assumed to be of neurological origin. During 2002, nearly 3,000 persons with WNV meningitis or encephalitis (or both) were reported in the United States; in suburban Cook County, Illinois, with 244 persons were hospitalized for WNV illnesses. The objective of this investigation was to describe the clinical and epidemiological features of identified cases of WNV neuroinvasive disease and rhabdomyolysis. Public health officials investigated patients hospitalized in Cook County, and identified a subset of WNV neuroinvasive disease patients with elevated creatine kinase levels. Cases were defined as hospitalized persons with a WNV infection, encephalitis or meningitis, and rhabdomyolysis. Retrospective medical record reviews were conducted and data was abstracted with a standardized data collection instrument. Eight patients with West Nile encephalitis and one with West Nile meningitis were identified with rhabdomyolysis. Median age of the nine patients was 70 years (range, 45-85 years), and eight were men. For all nine patients, the peak CK level was documented a median of 2 days after hospitalization (range, 1-24 days). Median CK level during hospitalization for all case-patients was 3,037 IU (range, 1,153-42,113 IU). Six patients had history of recent falls prior to admission. Although the temporal relationship of rhabdomyolysis and neurological WNV illness suggested a common etiology, these patients presented with complex clinical conditions which may have led to development of rhabdomyolysis from other causes. The spectrum of WNV disease requires further investigation to describe this and other clinical conditions associated with WNV infection.

Rhabdomyolysis associated with acute renal failure in patients with severe acute respiratory syndrome

An outbreak of severe acute respiratory syndrome (SARS) occurred in Taiwan in 2003. SARS complicated with rhabdomyolysis has rarely been reported. This study reported three cases of rhabdomyolysis developing during the clinical course of SARS. Thirty probable SARS patients were admitted to the isolation wards at Linkou Chang Gung Memorial Hospital between 4 April and 4 June 2003. Thirty patients, including four men and 26 women aged from 12 to 87 years (mean age 40). Eleven (36.7%) patients had respiratory failure and required mechanical ventilation with paralytic therapy; three (10%) patients had rhabdomyolysis complicated with acute renal failure and one received haemodialysis; four (13.3%) patients died. Three cases with rhabdomyolysis all received sedative and paralytic therapy for mechanical ventilation. Haemodialysis was performed on one patient. Two patients died from multiple organ failure, and one patient fully recovered from rhabdomyolysis with acute renal failure. SARS is a serious respiratory illness, and its aetiology is a novel coronavirus. Rhabdomyolysis resulting from SARS virus infection was strongly suspected. Immobilisation under paralytic therapy and steroids may also be important in developing rhabdomyolysis.

Factors predictive of acute renal failure and need for hemodialysis among ED patients with rhabdomyolysis

OBJECTIVE

We assessed the primary causes of rhabdomyolysis, the factors associated with the development of acute renal failure (ARF), and the need for hemodialysis (HD) among a series of patients presenting to an urban emergency department with rhabdomyolysis.

METHODS

A chart review between January 1992 and December 1995 was conducted of patients aged 18 years or older with a diagnosis of rhabdomyolysis and an initial serum creatine phosphokinase greater than 1000 U/L. Patients were excluded if they had evidence of myocardial ischemia, cerebrovascular insufficiency, or the development of rhabdomyolysis after hospitalization. Demographic information, presumed causative factors, past medical history, medication usage, and laboratory data were collected.

RESULTS

Ninety-seven patients (93 men, 4 women) were enrolled, with a mean age of 35.7 years. The most common causes of rhabdomyolysis were cocaine (30), exercise (29), and immobilization (18). Seventeen of 97 (17.5%) patients developed ARF; 8 patients (8.25%) needed HD. Several clinical and laboratory factors were statistically associated with development of ARF and need for HD. The only variable that was predictive of both ARF and need for HD in separate multivariate regression models was the initial creatinine (Cr). Initial blood urea nitrogen also was predictive of the need for HD. No patient developed ARF with an initial Cr less than 1.7 mg/dL.

CONCLUSION

Acute renal failure and need for HD are common complications of rhabdomyolysis. Except for initial serum Cr and blood urea nitrogen, clinical and laboratory factors were not reliable predictors for the development of ARF or need for HD.

Bench-to-bedside review: Rhabdomyolysis -- an overview for clinicians

Rhabdomyolysis ranges from an asymptomatic illness with elevation in the creatine kinase level to a life-threatening condition associated with extreme elevations in creatine kinase, electrolyte imbalances, acute renal failure and disseminated intravascular coagulation. Muscular trauma is the most common cause of rhabdomyolysis. Less common causes include muscle enzyme deficiencies, electrolyte abnormalities, infectious causes, drugs, toxins and endocrinopathies. Weakness, myalgia and tea-colored urine are the main clinical manifestations. The most sensitive laboratory finding of muscle injury is an elevated plasma creatine kinase level. The management of patients with rhabdomyolysis includes early vigorous hydration.

D3 dopamine and kappa opioid receptor alterations in human brain of cocaine-overdose victims

Cocaine is thought to be addictive because chronic use leads to molecular adaptations within the mesolimbic dopamine (DA) circuitry, which affects motivated behavior and emotion. Although the reinforcing effects of cocaine are mediated primarily by blockade of DA uptake, reciprocal signaling between DA and endogenous opioids has important implications for understanding cocaine dependence. We have used in vitro autoradiography and ligand binding to map D3 DA and kappa opioid receptors in the human brains of cocaine-overdose victims. The number of D3 binding sites was increased one-to threefold over the nucleus accumbens and ventromedial sectors of the caudate and putamen from cocaine-overdose victims, as compared to age-matched and drug-free control subjects. D3 receptor/cyclophilin mRNA ratios in the nucleus accumbens were increased sixfold in cocaine-overdose victims over control values, suggesting that cocaine exposure also affects the expression of D3 receptor mRNA. The number of kappa opioid receptors in the nucleus accumbens and other corticolimbic areas from cocaine fatalities was increased twofold as compared to control values. Cocaine-overdose victims exhibiting preterminal excited delirium had a selective upregulation of kappa receptors measured also in the amygdala. Understanding the complex regulatory profiles of DA and opioid synaptic markers that occur with chronic misuse of cocaine may suggest multitarget strategies for treating cocaine dependence.