Aim. To compare the efficacy of adding original moxonidine and its generics to previous ineffective antihypertensive therapy in patients with poorly controlled arterial hypertension (AH).Material and methods. This observational prospective non-randomized study included 120 patients with poorly controlled blood pressure on the previous antihypertensive therapy. All patients underwent clinical evaluation, including anthropometric and laboratory indexes, and 24-hour blood pressure monitoring (24-h BPM) at baseline and after 12 weeks of observation. Office systolic and diastolic blood pressure (SBP and DBP) and heart rate (HR) were recorded after 4 and 12 weeks of treatment. During the observation period, 4 equal groups were formed: group 1, Physiotens was added to the treatment; group 2, Moxonitex; group 3, Moxonidine SZ; and group 4, Moxonidine Canon. Statistical analysis was performed with the StatTech v.4.2.7 software (© OOO StatTech, Russia).Results. After 4 weeks of therapy, the BP target was achieved significantly more frequently in group 1 (63% of patients) compared to groups 2 (36.7% of patients), 3 (16.7% of patients), and 4 (16.7% of patients) (p<0.05). At 12 weeks, office SBP, DBP, and HR were significantly decreased in all groups, but the decrease was significantly greater in group 1. The therapy was associated with a more pronounced decrease in all studied 24-h BPM parameters in the Physiotens group than in other groups, as well as with a significantly more frequent normalization of the 24-h BP profile, in 66.7% of patients vs. 46.7%, 33.4%, and 23.2% of patients in groups 2, 3, and 4, respectively.Conclusion. The treatment with original moxonidine demonstrated advantages over generic drugs in terms of achieving the BP goal, reducing office BP and HR, and improving 24-h BPM parameters.