Moxonidine is an anti-hypertensive, a drug prescribed to lower high blood pressure. It reduces the activation of the sympathetic nervous system, decreasing blood vessel resistance and thus the workload of the heart. In addition to its effects on blood pressure, moxonidine has been shown to reduce insulin resistance and enhance glucose metabolism, which may assist in cardiovascular disease prevention. Like other centrally acting anti-hypertensive agents, it is usually prescribed when alternative medication types are not working or cannot be given to a patient due to health considerations.
One way by which the sympathetic nervous system controls blood pressure is through increased vascular resistance and cardiac output, so diminishing these effects is a method of hypertension treatment. In the brain, α2 receptors for neurepinephrine, when activated, reduce the effects of the sympathetic nervous system and lower vascular resistance, decreasing blood pressure. A group of proteins that form a subclass of the α2s are imidazoline receptors. Several anti-hypertensive drugs, including clonidine and moxonidine, work through binding to α2 receptors and activating them. Unlike clonidine, moxonidine is specific in binding to the imidazole receptors, which makes it more selective.
Since it operates directly on the brain's physiological regulatory centers, monoxidine is classified as a centrally acting antihypertensive drug. Commonly, diuretics or ACE inhibitors, followed by beta blockers, will be prescribed first to hypertensive patients before the centrally acting agents, to which treatment resorts only when these other medications have failed or cannot be safely given. It appears equally effective compared to similar agents, like clonidine, acting directly on the central nervous system. Blood pressure reduction in patients who take this drug has been as much as 20%.
Insulin resistance syndrome, a complex of factors including decreased ability to metabolize glucose and excess abdominal fat, is correlated with increased risk of cardiovascular diseases. In various laboratory tests, moxonidine was shown to increase insulin sensitivity and improve cellular uptake of glucose, both important factors in protecting health. It also diminished weight gain and lowered systemic lipid levels in test animals. Similar studies of animal kidney failure indicated that the drug protected against further renal damage.
Normally prescribed to adults according to the level of hypertension, moxonidine is not recommended for patients with heart conditions involving hypotension or circulatory problems, since it could exacerbate these symptoms. It is not usually prescribed to those with kidney disease, nor is it given along with the thiazide class of diuretic drugs, which could cause hypotension when combined with another medication with similar effects. It should be noted that in clinical trials, moxonidine had fewer side effects than did clonidine.