Hypertension Knowledge Centre
Centrally Acting Drugs
The Effects of Moxonidine
Effects on catecholamine levels
Single oral doses of moxonidine have been shown to reduce plasma norepinephrine levels in patients with hypertension.74 The fall in plasma norepinephrine levels correlated with the reduction in systolic (p=0.05) and diastolic (p=0.02) blood pressures.
Reductions in plasma catecholamine levels have also been reported in some clinical studies which evaluated this parameter. For example, 24 weeks of moxonidine treatment in obese hypertensive patients produced statistically significant reductions in plasma arterial levels of epinephrine (-22.5%, p<0.005 versus pretreatment) and norepinephrine (-20.4%, p<0.01 versus pretreatment).37 There was a statistically significantly greater reduction in patients whose blood pressure was controlled compared with non-responders (p<0.003). Click here to read more on this study.
Haemodynamic effects
The haemodynamic effects of a single oral dose of moxonidine (0.4mg) were investigated in ten patients with mild-to-moderate hypertension.17 There was a significant fall in mean blood pressure over a 4-hour observation period from 176/105 to 158/95 mmHg (p<0.01). This was accompanied by an approximately 16% decrease in systemic vascular resistance from 1695 to 1427 dyn.sec/cm5 (p<0.01), with no significant change in cardiac output (figure 27). No significant changes were recorded for either pulmonary artery pressure or pulmonary vascular resistance. The authors concluded that moxonidine lowered blood pressure by reducing systemic vascular resistance while maintaining cardiac output and heart rate.
Figure 27: Effect of moxonidine on cardiac output and systemic vascular resistance. Adapted from 17
Metabolic effects
The beneficial effects of moxonidine on glucose and insulin metabolism are described in the diabetes section. Its effects on microalbuminuria are described in the renal protection section.
Moxonidine appears to have a neutral effect on the lipid profile.34,35 A study in 20 hypertensive patients looked at the effects of moxonidine on lipid fractions; there were no statistically significant changes in HDL, LDL or total cholesterol, or triglycerides.75 There were also no significant changes in these parameters in an analysis of pooled results fromseveral placebo-controlled trials.70