Comparative Pharmacology
Head-to-head clinical analysis: LEVATOL versus METOPROLOL TARTRATE AND HYDROCHLOROTHIAZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVATOL versus METOPROLOL TARTRATE AND HYDROCHLOROTHIAZIDE.
LEVATOL vs METOPROLOL TARTRATE AND HYDROCHLOROTHIAZIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Labetalol is a nonselective beta-adrenergic antagonist with additional alpha1-adrenergic blocking activity. It competitively blocks beta1 and beta2 receptors and alpha1 receptors, leading to decreased heart rate, myocardial contractility, and systemic vascular resistance.
Metoprolol is a cardioselective beta-1 adrenergic receptor antagonist that reduces heart rate, myocardial contractility, and blood pressure. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium and water, thereby reducing plasma volume and blood pressure.
50 mg orally once daily, increasing to 100 mg once daily after 2 weeks if tolerated; maximum 200 mg once daily.
Oral: 50-100 mg metoprolol tartrate/12.5-25 mg hydrochlorothiazide once or twice daily; maximum 200 mg metoprolol/50 mg hydrochlorothiazide per day.
None Documented
None Documented
Terminal elimination half-life is 6-8 hours; prolonged to 10-16 hours in severe renal impairment (CrCl <30 mL/min).
Metoprolol: 3–7 h (terminal), clinical context: may require twice-daily dosing; prolonged in hepatic impairment. Hydrochlorothiazide: 6–15 h (terminal), clinical context: supports once-daily dosing; prolonged in renal impairment.
Renal excretion accounts for 55-60% as unchanged drug; biliary/fecal elimination accounts for 40-45% as metabolites and unchanged drug.
Metoprolol: <5% renal (unchanged), >95% hepatic metabolism, metabolites excreted renally. Hydrochlorothiazide: >95% renal (unchanged).
Category C
Category C
Beta-Blocker
Beta-Blocker