Hypertension Knowledge Centre
Centrally Acting Drugs
Long-term efficacy
Schwarz & Kandziora (1990)28 assessed the efficacy of moxonidine in an open, multicentre, 12-month clinical trial in 141 ambulant hypertensive patients with mean sitting diastolic pressure >95 mmHg. The dosage was started at 0.2mg/day, and was individually titrated over a period of three weeks up to a maximum of 0.8mg/day in divided doses. The median age of the patients was 57 years (range 16-79 years). A subgroup of 49 patients from one trial centre in this study continued moxonidine treatment for a second year.43
The mean sitting blood pressure fell over a period of three weeks on moxonidine from 172/103 to 151/88 mmHg and these reductions were maintained throughout the study (figure 9). The reductions in standing blood pressure were of similar magnitude.
Figure 9: Change in mean sitting blood pressure during up to two years of treatment with moxonidine. Adapted from 28,43
At 12 months, 97% of patients were satisfactorily controlled on daily doses of 0.4mg or less. On discontinuation of treatment, blood pressure gradually increased towards baseline with no evidence of a rebound effect.
Trieb, Jäger, Hughes, et al (1995)29 demonstrated the long-term efficacy of moxonidine in an open, multicentre study of 223 outpatients with mild-to-moderate hypertension who were treated with moxonidine (0.2-0.6mg/day) for 12 months. Supplementary use of diuretics was permitted in patients who did not respond adequately to moxonidine 0.6mg/day. Patients were eligible for enrolment if they had mean sitting blood pressure in the range ≥160/95 to ≤240/114 mmHg.
Per protocol analysis showed that 12 weeks of moxonidine therapy reduced mean sitting blood pressure by 25/15 mmHg. Similar reductions were maintained for the subsequent 40 weeks of the study; the reduction in mean blood pressure at 52 weeks was 27/16 mmHg. Blood pressure reduction in a subgroup of patients aged 65 years or more was at least as great as in a younger group at 52 weeks.
Satisfactory response to therapy (defined as diastolic blood pressure ≤90 mmHg or a reduction in diastolic blood pressure of ≥ mmHg) was observed in 82% of patients at week 12 and in 85% of patients at week 52. There was no clinically significant change in heart rate during the study. Rebound hypertension was not observed on termination of moxonidine therapy.