Successful treatment of cocaine-induced cardiotoxicity with carvedilol therapy

Beta Blocker Therapy in Heart Failure Patients with Active Cocaine Use: A Systematic Review

Background

Cocaine use is associated with multiple cardiovascular complications including heart failure. The use of different types of beta blockers in heart failure patients with active cocaine use is still a matter of debate. In this review, our objective is to systematically review the available literature regarding the use of beta blockers in the treatment of heart failure patients with concurrent cocaine use.

Methods

PubMed, EMBASE, Web of Science, and Clinical Trials.gov were searched from inception to March 2019 using the Medical Subject Headings (MeSH) terms “cocaine”, “heart failure”, “beta blocker,” and “cardiomyopathy”. Only studies containing the outcomes of heart failure patients with active cocaine use who were treated with beta blockers were included.

Results

The search resulted in 2072 articles out of which 12 were finally included in the review. A total number of participants were 1994 with a median sample size of 111. Most of the studies were retrospective in nature with Oxford Centre for Evidence-Based Medicine (OCEBM) Levels of Evidence from 3 to 5. The main primary outcomes included readmission rates, mortality, left ventricular ejection fraction (LVEF) improvement, New York Heart Association (NYHA) functional class, and major adverse cardiovascular events (MACEs). In the studies analyzed, beta blockers were found to have either a beneficial or a neutral effect on primary outcomes in heart failure patients with active cocaine use.

Conclusion

The use of beta blocker therapy appears to be safe and beneficial in heart failure patients with active cocaine use, although the evidence is not robust. Furthermore, large-scale studies are required to confirm this finding.

Improvement in clinical outcomes of patients with heart failure and active cocaine use after β-blocker therapy

BACKGROUND

Cocaine use has a high prevalence in the United States and can be associated with significant cardiovascular disease, even in asymptomatic users. β-Adrenergic receptor hyperactivation is the underlying pathophysiologic pathway of cocaine cardiotoxicity. β-Blocker therapy is controversial in patients with active cocaine use.

HYPOTHESIS

β-Blocker therapy is associated with clinical improvement in patients with heart failure despite active cocaine use.

METHODS

In a single-center, retrospective chart analysis, patients with newly diagnosed heart failure and active cocaine use who had been started on β-blocker therapy were reviewed. The New York Heart Association (NYHA) functional class and the left ventricular ejection fraction (LVEF) were recorded at baseline and after 12 monthsnthsnths of β-blocker use. Patients were excluded if they had been on prior β-blocker therapy, had other reasons for volume overload, had chronic kidney disease stages G4 or G5, or had a life expectancy <12 months.

RESULTS

Thirty-eight patients were identified; most were African American males. A statistically significant improvement was found in both NYHA functional class (P < 0.0001) and LVEF (P < 0.0001) after 12 months of β-blocker therapy. No major adverse cardiovascular events occurred in this population.

CONCLUSIONS

β-Blocker use in cocaine users with heart failure with a reduced ejection fraction is associated with a lower NYHA functional class and a higher LVEF at 12-month follow-up. No major adverse cardiovascular events were observed.

β-Blockers, Cocaine, and the Unopposed α-Stimulation Phenomenon

Cocaine abuse remains a significant worldwide health problem. Patients with cardiovascular toxicity from cocaine abuse frequently present to the emergency department for treatment. These patients may be tachycardic, hypertensive, agitated, and have chest pain. Several pharmacological options exist for treatment of cocaine-induced cardiovascular toxicity. For the past 3 decades, the phenomenon of unopposed α-stimulation after β-blocker use in cocaine-positive patients has been cited as an absolute contraindication, despite limited and inconsistent clinical evidence. In this review, the authors of the original studies, case reports, and systematic review in which unopposed α-stimulation was believed to be a factor investigate the pathophysiology, pharmacology, and published evidence behind the unopposed α-stimulation phenomenon. We also investigate other potential explanations for unopposed α-stimulation, including the unique and deleterious pharmacologic properties of cocaine in the absence of β-blockers. The safety and efficacy of the mixed β-/α-blockers labetalol and carvedilol are also discussed in relation to unopposed α-stimulation.

Carvedilol does not reduce cocaine use in methadone-maintained cocaine users

INTRODUCTION

The goal of this study was too test the efficacy of carvedilol (CAR), an adrenergic blocker, for reducing cocaine use in individuals with cocaine use disorder (CUD). We conducted a 17-week, double-blind, randomized controlled trial with 3 treatment arms: 25mg CAR, 50mg CAR, and placebo.

METHODS

One hundred and six treatment-seeking opioid and cocaine-dependent participants, who were also maintained on methadone during study participation, were randomized to placebo (n=34), 25mg/day CAR (n=37) or 50mg/day CAR (n=35). The main outcome measures were cocaine and opioid use as assessed by urine drug screening and self-reported drug use.

RESULTS

No significant group differences were found for treatment retention with 56% of the placebo, 76% of the 25mg and 66% of the 50mg CAR groups (p>0.05) completing treatment. The percentage (SD) of cocaine positive urines during the trial showed an overall treatment effect: 59.2 (38.9) for the placebo, 50.8 (33.8) for the 25mg and 75.1 (33.2) for the 50mg CAR group. In post hoc comparisons, neither the 25 nor 50mg CAR condition differed significantly from the placebo; however, the 25mg CAR group had a significantly lower proportion of cocaine-positive urines than the 50mg group. No significant group differences were found for the percentage of self-reported days of cocaine abstinence during the trial: 72.9 (25.3) for placebo, 72.9 (29) for CAR 25mg, and 59.3 (31.7) for CAR 50mg. Significant groups differences in the proportion of opioid positive urines submitted were not observed (p>0.05). Baseline cocaine withdrawal severity did not predict treatment response (p>0.05).

CONCLUSIONS

These findings did not support the efficacy of CAR for the treatment of cocaine use in cocaine and opioid dependent participants maintained on methadone. Further, CAR doses >25mg should not be used to avoid possible increases in cocaine and opioid use.

Treatment of cocaine cardiovascular toxicity: a systematic review

INTRODUCTION

Cocaine abuse is a major worldwide health problem. Patients with acute cocaine toxicity presenting to the emergency department may require urgent treatment for tachycardia, dysrhythmia, hypertension, and coronary vasospasm, leading to pathological sequelae such as acute coronary syndrome, stroke, and death.

OBJECTIVE

The objective of this study is to review the current evidence for pharmacological treatment of cardiovascular toxicity resulting from cocaine abuse.

METHODS

MEDLINE, PsycINFO, Database of Abstracts of Reviews of Effects (DARE), OpenGrey, Google Scholar, and the Cochrane Library were searched from inception to November 2015. Articles on pharmacological treatment involving human subjects and cocaine were selected and reviewed. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines. Treatment recommendations were compared to current American College of Cardiology/American Heart Association guidelines. Special attention was given to adverse drug events or treatment failure. The search resulted in 2376 articles with 120 eligible involving 2358 human subjects. Benzodiazepines and other GABA-active agents: There were five high-quality (CEBM Level I/II) studies, three retrospective (Level III), and 25 case series/reports (Level IV/V) supporting the use of benzodiazepines and other GABA-active agents in 234 subjects with eight treatment failures. Benzodiazepines may not always effectively mitigate tachycardia, hypertension, and vasospasm from cocaine toxicity. Calcium channel blockers: There were seven Level I/II, one Level III, and seven Level IV/V studies involving 107 subjects and one treatment failure. Calcium channel blockers may decrease hypertension and coronary vasospasm, but not necessarily tachycardia. Nitric oxide-mediated vasodilators: There were six Level I/II, one Level III, and 25 Level IV/V studies conducted in 246 subjects with 11 treatment failures and two adverse drug events. Nitroglycerin may lead to severe hypotension and reflex tachycardia. Alpha-adrenoceptor blocking drugs: There were two Level I studies and three case reports. Alpha-1 blockers may improve hypertension and vasospasm, but not tachycardia, although evidence is limited. Alpha-2-adrenoceptor agonists: There were two high-quality studies and one case report detailing the successful use of dexmedetomidine. Beta-blockers and β/α-blockers: There were nine Level I/II, seven Level III, and 34 Level IV/V studies of β-blockers, with 1744 subjects, seven adverse drug events, and three treatment failures. No adverse events were reported for use of combined β/α-blockers such as labetalol and carvedilol, which were effective in attenuating both hypertension and tachycardia. Antipsychotics: Seven Level I/II studies, three Level III studies, and seven Level IV/V case series and reports involving 168 subjects have been published. Antipsychotics may improve agitation and psychosis, but with inconsistent reduction in tachycardia and hypertension and risk of extrapyramidal adverse effects. Other agents: There was only one high level study of morphine, which reversed cocaine-induced coronary vasoconstriction but increased heart rate. Other agents reviewed included lidocaine, sodium bicarbonate, amiodarone, procainamide, propofol, intravenous lipid emulsion, propofol, and ketamine.

CONCLUSIONS

High-quality evidence for pharmacological treatment of cocaine cardiovascular toxicity is limited but can guide acute management of associated tachycardia, dysrhythmia, hypertension, and coronary vasospasm. Future randomized prospective trials are needed to evaluate new agents and further define optimal treatment of cocaine-toxic patients.