Experience with esmolol for the treatment of cocaine-associated cardiovascular complications

The effects of lidocaine pretreatment on cocaine neurotoxicity and lethality in mice

OBJECTIVE

To evaluate the effects of an antiarrhythmic dose of lidocaine on cocaine-induced ataxia, seizures, and death in mice.

METHODS

A randomized, controlled, blinded investigation was conducted using 220 female Swiss albino mice. Groups of 20 animals received intraperitoneal (IP) administration of either 31.6 mg/kg of lidocaine hydrochloride in 0.9% NaCl (ten animals) or an equal volume of 0.9% NaCl solution (ten animals). After 5 minutes, all the animals received IP cocaine in incremental doses ranging from 40 to 110 mg/kg. The animals were observed for ataxia, seizures, and death. The animals pretreated with lidocaine were compared with the control animals for the number of adverse effects from cocaine at each dose tested.

RESULTS

Lidocaine significantly increased the overall incidences of cocaine-induced ataxia (p = 0.02) and seizures (p < 0.001). However, pretreatment with lidocaine offered protection against cocaine lethality (p < 0.0001).

CONCLUSION

In this preexposure model, lidocaine protects mice against cocaine-induced lethality. These effects seem to be independent of convulsive activity. Further study is required to determine the safety and efficacy of lidocaine for the management of cocaine-induced arrhythmias.

Nitroglycerin in the treatment of cocaine associated chest pain--clinical safety and efficacy

The optimal medical regimen for the treatment of cocaine associated myocardial ischemia has not been defined. While animal and human data demonstrate the risks of beta-adrenergic blockade, studies in the cardiac catheterization laboratory suggest a beneficial role of nitroglycerin. We performed a prospective multicenter observational study to evaluate the clinical safety and efficacy of nitroglycerin in the treatment of cocaine associated chest pain at six municipal hospital centers. Of 246 patients presenting with cocaine associated chest pain, 83 patients were treated with nitroglycerin at the discretion of the treating physician. Relief of chest pain and/or adverse hemodynamic outcome were the primary endpoints. Baseline comparisons of patients treated with nitroglycerin to those not treated with nitroglycerin found that the treated patients were at higher risk of ischemic heart disease. They were older (36 years vs 32 years, p = 0.0008), more likely to have an ischemic electrocardiogram (27% vs 4%, p < 0.0001), to be admitted (94% vs 40%, p < 0.0001), and to have a discharge diagnosis of ischemic heart disease (41% vs 9%, p < 0.0001). Nitroglycerin was beneficial in 41 patients (49%; 95% CI, 38-60%): 37 patients (45%) had relief or reduction in the severity of chest pain and 4 patients (5%) had other beneficial effects. Only one patient had an adverse outcome (transient hypotension in the setting of a right ventricular infarct). Nitroglycerin is safe and possibly effective in the treatment of cocaine associated chest pain.