Determination of cocaine, metabolites and a crack cocaine biomarker in whole blood by liquid-liquid extraction and UHPLC-MS/MS.

Cocaine is a potent stimulant drug widely abused that exists in two forms: as a hydrochloride salt and as a free base (crack). Cocaine and the inactive metabolite benzoylecgonine can be determined to reveal any kind of cocaine use, whereas the pyrolysis product anhydroecgonine methyl ester (AEME) can be determined to reveal crack smoking. There are many bioanalytical LC-MS/MS methods used for the determination of cocaine, metabolites and AEME. In these methods, chromatographic separation is usually performed by HPLC and sample preparation by solid phase extraction. For the first time, an UHPLC-MS/MS method for the simultaneous determination of cocaine, benzoylecgonine, cocaethylene and AEME in blood using a sample preparation by liquid-liquid extraction was developed and validated. Extraction recoveries were approximately 80%, 40%, 80% and 80%, respectively, obtained by using a mixture of MTBE/2-propanol (70:30, v:v). Chromatographic separation was performed on a core shell biphenyl UHPLC column (100×2.1mm ID, 1.7µm particles). Method validation showed that the method is precise, accurate, robust and sensitive for its purposes. Limit of quantification (LOQ) concentrations were 0.7-1.5ng/mL. The method was used to determine cocaine, benzoylecgonine, cocaethylene and AEME in 22 blood samples collected from victims of sudden, unexpected or violent death in Sao Paulo (Brazil). Concentrations ≥LOQ were observed in 19, 21, 10 and 10 of these samples, respectively.

Comparison of Cocaine/Crack Biomarkers Concentrations in Oral Fluid, Urine and Plasma Simultaneously Collected From Drug Users.

The use of oral fluid (OF) as an alternative specimen for drug analysis has become very popular in forensic toxicology. Many clinical studies have evaluated the correlations between concentrations of cocaine and its metabolites in OF and other matrices, but results have shown high variability. In addition, there are no data available regarding the correlations between biomarkers of crack-cocaine use in different matrices. This study evaluated the relationship between concentrations of cocaine/crack-cocaine biomarkers in OF, urine and plasma samples collected from cocaine users. All samples were analyzed for the presence of cocaine (COC), benzoylecgonine (BZE) and anhydroecgonine (AEC) by a validated liquid chromatography-mass spectrometry method. Median COC, BZE and AEC concentrations ranged from 4.20 to 33.26 ng/mL, from 13.03 to 3,615.86 ng/mL and from 7.40 to 1,892.5 ng/mL across matrices, respectively. The relationship between drug concentrations in OF versus plasma (OF/P) and OF versus urine (OF/U) was evaluated by their coefficients of determination (R2). Least-squares regression analyses demonstrated significant correlations between OF/P and OF/U for cocaine and BE (P < 0.05), with R2 = 0.17, 0.07 for cocaine and R2 = 0.73, 0.45 for BE, respectively. The correlation coefficients (r) found for BZE, COC and AEC in OF/P and OF/U were 0.85 and 0.67 (P < 0.05); 0.41 and 0.26 (P < 0.05); and 0.30 and -0.37 (P > 0.05), respectively. Many factors contribute to the variability of drug correlation ratios in studies involving random samples, including uncertainty about the time of last administration and dosage. Overall, we found significant R2 values for COC and BZE in OF/P and OF/U, but not for AEC. Despite the good correlations found in some cases, especially for BZE, the large variation in drug concentrations seen in this work suggests that OF concentrations should not be used to estimate concentrations of COC, BZE or AEC in plasma and/or urine.

Effects of chronic exposure to crack cocaine on the respiratory tract of mice.

Smoked cocaine (crack cocaine) causes several forms of injury to the respiratory tract, including asthma exacerbations, lung edema and hemorrhage, and nasal mucosal alterations. Few studies, however, have assessed respiratory tract pathology in habitual users of crack cocaine. Here, we describe the histological alterations in the respiratory tract of mice caused by chronic inhalation of crack cocaine. Twenty 2-month-old BALB/c mice were exposed to the smoke of 5 g crack cocaine in an inhalation chamber once a day for two months and compared to controls (n = 10). We then morphometrically analyzed nose and bronchiolar epithelial alterations, bronchiolar and alveolar macrophage cell density, alveolar hemosiderin content, and in addition determined the vasoconstriction index and the wall thickness of pulmonary arteries. The serum cocaine level was 212.5 ng/mL after a single inhalation. The mucus content of the nasal epithelium increased in crack-exposed animals, and the nasal and bronchial epithelium thickness decreased significantly. The alveolar hemosiderin content and the alveolar and bronchiolar macrophage cell density increased in animals exposed to crack. The vasoconstriction index increased in the pulmonary arteries of the exposed group. Chronic crack cocaine inhalation causes extensive histological changes along the entire respiratory tract.

Transient left ventricular apical ballooning after cocaine use: is catecholamine cardiotoxicity the pathologic link?

We describe a patient who developed acute chest pain after using cocaine and had ST-segment elevation in the anterior leads on electrocardiography with mild elevation of cardiac enzymes. Cardiac catheterization showed normal coronary arteries with no coronary vasospasm. Left ventricular angiography revealed typical ballooning of the left ventricular apex during systole with an estimated left ventricular ejection fraction of 25%. The symptoms improved during the next few hours, and follow-up echocardiography 4 days later showed complete resolution of the left ventricular dysfunction. Transient left ventricular apical ballooning (LVAB) was diagnosed. To our knowledge, LVAB (also known as Takotsubo cardiomyopathy or "broken heart syndrome") has not been reported previously in association with cocaine use. We discuss the possible pathophysiologic link between LVAB and cocaine-induced cardiotoxicity.

Effects of baclofen on cocaine self-administration: opioid- and nonopioid-dependent volunteers.

Preclinical and clinical studies suggest that GABAB receptor agonists selectively decrease cocaine use. The behavioral mechanism for the interaction between baclofen and cocaine in humans is not known, nor have its effects been characterized in individuals dependent on both cocaine and methadone. The objective of this study is to determine how maintenance on baclofen influences smoked cocaine's reinforcing and subjective effects, mood and cocaine craving prior to and after the initiation of cocaine use in cocaine-dependent volunteers with and without concurrent opioid dependence. Nontreatment-seeking volunteers (10 nonopioid dependent; seven methadone maintained), residing on an in-patient research unit for 21 days, were maintained on each baclofen dose (0, 30, 60 mg po) for 7 days. A smoked cocaine dose-response curve (0, 12, 25, 50 mg) was determined twice: on days 3-4 and days 6-7 of each baclofen maintenance condition. Cocaine sessions began with a sample trial, when participants smoked the cocaine dose available that session, and five choice trials, when participants chose between smoking the available cocaine dose or receiving one 5 dollars merchandise voucher. The results show that in the nonmethadone group, baclofen (60 mg) decreased self-administration of a low cocaine dose (12 mg). In the methadone group, baclofen decreased craving for cocaine. In both groups, baclofen decreased cocaine's effects on heart rate. Baclofen did not alter cocaine's robust subjective effects (eg 'High,' 'Stimulated') for either group. The results from this laboratory study appear consistent with clinical evidence showing that baclofen decreases cocaine use in nonopioid-dependent patients seeking treatment for cocaine dependence. The distinct pattern of effects in methadone-maintained participants suggests baclofen may not be effective in opioid-dependent cocaine users.

Injection drug use and crack cocaine smoking: independent and dual risk behaviors for HIV infection.

PURPOSE: Previous studies have examined the practices of injecting drugs or smoking crack cocaine as high-risk, but independent, factors for HIV transmission. To explore the independent and dual risks of injection practices and crack smoking, this study examined HIV seroprevalence rates among distinct drug user groups, based on patterns of daily administration. METHODS: A sample of 3,555 drug users and neighborhood controls in urban Miami, FL and rural Belle Glade and Immokalee, FL were partitioned into four mutually-exclusive groups: 1) injection drug users (IDUs); 2) crack-cocaine smokers; 3) dual users who both smoked crack and injected drugs; and 4) non-drug-user controls. RESULTS: HIV seroprevalence rates were 45.1% for IDUs, 30.5% for dual users, 20.1% for crack smokers and 7.3% for controls. Multivariate logistic regression analysis found that when compared with controls odds ratios for HIV seropositivity were 9.81 for IDUs, 5.27 for dual users, and 2.24 for crack smokers. CONCLUSIONS: These findings provide evidence of: 1) behavioral and structural co-factors that influence HIV exposure patterns among drug users; and 2) the substantially higher risk of HIV infection among IDUs compared with other drug users. Intervention strategies must be tailored for the specific drug use subpopulations to optimize efficacy.

Thoracic aortic dissection associated with cocaine abuse.

Cardiovascular complications of cocaine abuse include myocardial ischemia and infarction, dysrhythmias, cardiomyopathies and aortic dissection. The case in point pertains to a 26-year-old, Caucasian male, substance abuser who suffered a thoracic aortic dissection following the use of crack cocaine. The autopsy and histological findings showed a connective tissue abnormality including a focal microcystic medial necrosis and a fragmentation of the elastic fibers in the arterial walls. Blood concentrations of cocaine and benzoylecgonine, taken individually, were considered to be within a potentially toxic range. Blood concentrations of methadone also indicated use of this drug at the same time. The small amounts of morphine found in the blood and urine were compatible with heroine or morphine use more than 24 h before death.

Correlation between pharmacological effects and plasma cocaine concentrations after smoked administration.

The relationship between blood cocaine concentrations and pharmacological effects is of both theoretical and practical interest. This study utilized a computer-assisted smoking device for the delivery of three active doses (10, 20, and 40 mg) of cocaine base to seven human volunteers. Doses were administered in an ascending dose design with random placement of placebo. Physiological, subjective, and performance measures were collected concurrently with blood samples. Mean peak plasma cocaine concentrations were achieved at 2 min after the 20-mg and 40-mg doses and at 5 min after the 10-mg dose. Maximal responses in systolic and diastolic blood pressure, "feel", "good" drug, and drug "liking" subjective effects were also achieved immediately after drug administration. Pupil diameter and heart rate increases demonstrated a modest counter-clockwise hysteresis in relation to plasma cocaine concentrations shortly after dosing. Systolic and diastolic blood pressure, heart rate, and some subjective and performance measures of drug effect demonstrated a biphasic response after smoked cocaine. Initial increases above baseline levels were followed by an apparent compensatory decrease below baseline levels at a later time after smoked cocaine. Despite evidence of hysteresis and biphasic responses for some measures, linear correlation was obtained between mean plasma cocaine concentrations and several pharmacological effects over a period of 4 h after dosing. Several subjective and cardiovascular measures returned to baseline levels in the presence of detectable concentrations of cocaine.

Effects of phenytoin on cocaine self-administration in humans.

The goal of this pilot study was to determine the effects of phenytoin on cocaine self-administration in a human laboratory model. Subjects were randomized to either phenytoin (n = 6) or placebo (n = 7). Those assigned to phenytoin treatment received a single oral loading dose of 20 mg/kg. The phenytoin and placebo treatment groups did not differ in the number of tokens valued at $5, exchanged for cocaine. Similarly, the cardiovascular and subjective response to cocaine administration did not show a statistically significant treatment effect. In this laboratory model, phenytoin did not alter either the self-administration or effects of cocaine.

Multiple cocaine-induced seizures and corresponding cocaine and metabolite concentrations.

The etiology of seizures associated with cocaine use is unclear. Because cocaine seizures are relatively uncommon, they should be diagnosed by exclusion and a neurological workup to rule out central nervous system (CNS) catastrophe should be made. This report describes the clinical findings, treatment, and blood cocaine and metabolite concentrations in a patient who, on two separate occasions, had seizures associated with crack cocaine ingestion. Approximately 1 hour after the ingestion incidents, the patient had multiple, generalized seizures that abated spontaneously. His workup for CNS bleeding, infection, and trauma was negative. Cocaine concentrations on the first incident peaked at 2.48 mg/L and on the second incident peaked at 3.9 mg/L. Other clinical findings included tachycardia, hypertension, diaphoresis, and disorientation. Blood cocaine and metabolite analysis revealed extremely high concentrations. Other than the incident of seizures and transient cardiovascular aberrations, these high concentrations were tolerated by the patient without further sequelae. A review of cocaine-induced seizures and treatment is included.