Pharmacokinetics of metoprolol tartrate in patients with and without controlled arterial hypertension

Background. Metoprolol is a selective beta-blocker that is most commonly used in the pharmacotherapy of cardiovascular diseases, including hypertension (AH). Objective. To evaluate the pharmacokinetics of metoprolol tartrate in patients with controlled and uncontrolled AH. Materials and methods. An open cohort study was conducted at the Hospital Therapy Department of the Ryazan State Medical University in the Ryazan Regional Clinical Cardiology Dispensary. The study included 45 patients, including 29 with uncontrolled AH and 15 with controlled AH. All patients regularly take any two antihypertensive drugs (AHD) (lisinopril, amlodipine, and metoprolol tartrate) along with indapamide for a month. In the morning before and 2 h after taking metoprolol, venous blood samples were collected to assess the concentration of the analyzed substance (C0h and C2h, respectively) using high-performance liquid chromatography with tandem mass spectrometry. Results. Analysis of C0h and C2h of metoprolol tartrate did not show statistically significant differences in patients with controlled and uncontrolled AH. In 93 % of patients, C0h and in 57.8 %, C2h were below the lower limit of the therapeutic range, without statistically significant differences in controlled and uncontrolled AH. The median daily dose of metoprolol tartrate was 50 (25; 75) mg, which is insufficient according to the AH guidelines (the recommended dose is 100 mg). Conclusion. Thus, the pharmacokinetics of metoprolol tartrate did not make a significant contribution to achieving blood pressure control. In most cases, metoprolol tartrate concentration is below the therapeutic range, which is associated with a low drug dose.