Effects of labetalol on hemodynamic parameters and soluble biomarkers of inflammation in acute coronary syndrome in patients with active cocaine use.

Cocaine use is associated with increased cardiovascular mortality and can promote acute coronary syndrome (ACS). Use of beta-blockers is controversial in patients who use cocaine, and the safety and efficacy of these medications in ACS in patients actively using cocaine is unknown. We enrolled 90 patients with ACS and positive urine drug screen for cocaine. Patients received standard ACS therapy plus either labetalol (n = 60) or diltiazem (n = 30). Blood pressure and heart rate were measured at baseline and 48 hours. Levels of serum CD40 ligand, interleukin (IL)-6, and choline at baseline and 48 hours were determined. There were no baseline differences in hemodynamics or serum levels of inflammatory markers between the labetalol and diltiazem groups. Both groups experienced a significant and equivalent decrease in BP and HR at 48 hours compared with baseline. At 48 hours of treatment, there were significant decreases of 17% in CD40 ligand (P < .005) and 16% in IL-6 (P < .005) but no change in choline in the diltiazem group. Furthermore, in the labetalol group, there were significant differences of 30% in CD40 ligand (P < .005 time and group comparison), 22% in IL-6 (P < .005 time and group comparison), and 18% in choline (P < .005 time and group comparison). There were no adverse events during hospitalization in any patients who received labetalol. In conclusion, labetalol appears to be safe in cocaine-associated ACS. Furthermore, labetalol provides a beneficial hemodynamic response and, in comparison to diltiazem, potentiates an anti-inflammatory vascular response in this setting.

Renin profile, race, and antihypertensive efficacy with atenolol and labetalol.

In this randomised double-blind parallel study, we compared the efficacy of labetalol and atenolol in a group of black (n = 33) and white (n = 34) hypertensives with uncomplicated essential hypertension after obtaining pretreatment renin profiles. After single-blind placebo (14-21 days), patients with standing diastolic BP between 105-119 mmHg were randomised to receive either labetalol (100-800 mg twice daily) or atenolol (50-100 mg once daily) to achieve a DBP less than 90 mmHg. Dosage titration occurred at weekly intervals for labetalol and biweekly for atenolol. The supine BP decrease with atenolol was -18/-14 vs. -6/-6 mmHg in whites vs. blacks respectively. With labetalol, it was -13/-12 in whites and -2/-7 mmHg in blacks. Standing BPs were: -19/-14 vs. -4/-5, whites vs. blacks with atenolol and -17/-17 vs. -19/-9 mmHg with labetalol. Neither labetalol nor atenolol was as effective in black compared with white hypertensives. The atenolol but not labetalol BP response was positively correlated with pretreatment renin values.