Recently, the quality of generic metoprolol extended-release (ER) products has been called
into question with reports of inconsistent effects when switching from the brand name product
to a generic formulation. Problems with how the body processes these drugs could have serious
and widespread consequences given the high frequency of metoprolol ER use in the management
of various cardiovascular disorders, including high blood pressure, coronary heart disease,
heart failure, and cardiac arrhythmias. Investigators hypothesize that both product- and
subject-specific factors lead to variability in the way the body breaks down the drug
(pharmacokinetics) and clinical response to generic versus name brand metoprolol ER
formulations. Investigators will study the brand name and generic metoprolol ER formulations
in subjects with high blood pressure to compare the pharmacokinetics and cardiovascular
responses among equivalent labeled doses of each product (brand name and two approved
generics).
The study objective is to provide information on how the body breaks down generic and brand
name metoprolol ER products (pharmacokinetics) and how the body responds to generic and brand
name metoprolol ER products (pharmacodynamics) to better understand if generic metoprolol ER
products are as good as the brand name product.