Efaroxan (RX 821037) is a potent and selective alpha(2)-adrenoceptor antagonist. Additionally, Efaroxan is a selective antagonist at the imidazoline I1 receptor. Efaroxan promotes insulin secretion, in the absence of exogenous agonists, by a mechanism that involves inhibition of ATP-regulated K+ channels. Efaroxan was in clinical trials for the treatment of diabetes mellitus however its development has been discontinued.

Clorgiline is a monoamine oxidase (MAO) inhibitor. Specifically, it is an irreversible and selective inhibitor of MAO-A. Clorgiline was under investigation for antidepressant and anxiolytic potential but has never been marketed, likely due to efficacy concerns. It continues to see routine use as a molecular probe in biomedical research examining a number of neurological disease and cancer models. In addition to inhibiting the MAO-A receptor, it has also been found to bind to the sigma1 receptor, and with high affinity to the I2 imidazoline receptor.

Rilmenidine (brand names Albarel, Hyperium, Iterium and Tenaxum) is an imidazoline derivative used for the treatment of hypertension. Rilmenidine, an oxazoline compound with antihypertensive properties, acts on both medullary and peripheral vasomotor structures. Rilmenidine shows greater selectivity for imidazoline receptors than for cerebral alpha2-adrenergic receptors, distinguishing it from reference alpha2-agonists. Rilmenidine is as effective in monotherapy as all other first line classes of drugs, including diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and calcium antagonists. It is well tolerated and can be taken in combination for greater efficacy. Sedation and dry mouth are not prominent side effects and withdrawal hypertension is not seen when treatment is stopped abruptly. In addition to a reduction in blood pressure, Rilmenidine has been shown to improve glucose tolerance, lipid risk factors, and insulin sensitivity.

Moxonidine is a second-generation, centrally acting antihypertensive drug with a distinctive mode of action. Moxonidine activates I1-imidazoline receptors (I1-receptors). Imidazoline I1-receptor agonism represents a new mode of antihypertensive action to inhibit peripheral alpha-adrenergic tone by a central mechanism. Adrenaline, noradrenaline and renin levels are reduced, a finding consistent with central inhibition of sympathetic tone. Moxonidine acts centrally to reduce peripheral sympathetic activity, thus decreasing peripheral vascular resistance. In patients with mild to moderate hypertension, moxonidine reduces blood pressure (BP) as effectively as most first-line antihypertensives when used as monotherapy and is also an effective adjunctive therapy in combination with other antihypertensive agents. It improves the metabolic profile in patients with hypertension and diabetes mellitus or impaired glucose tolerance, is well tolerated, has a low potential for drug interactions and may be administered once daily in most patients. Moxonidine is a good option in the treatment of patients with mild to moderate hypertension, particularly as adjunctive therapy in patients with the metabolic syndrome.

Clorgiline is a monoamine oxidase (MAO) inhibitor. Specifically, it is an irreversible and selective inhibitor of MAO-A. Clorgiline was under investigation for antidepressant and anxiolytic potential but has never been marketed, likely due to efficacy concerns. It continues to see routine use as a molecular probe in biomedical research examining a number of neurological disease and cancer models. In addition to inhibiting the MAO-A receptor, it has also been found to bind to the sigma1 receptor, and with high affinity to the I2 imidazoline receptor.

Moxonidine is a second-generation, centrally acting antihypertensive drug with a distinctive mode of action. Moxonidine activates I1-imidazoline receptors (I1-receptors). Imidazoline I1-receptor agonism represents a new mode of antihypertensive action to inhibit peripheral alpha-adrenergic tone by a central mechanism. Adrenaline, noradrenaline and renin levels are reduced, a finding consistent with central inhibition of sympathetic tone. Moxonidine acts centrally to reduce peripheral sympathetic activity, thus decreasing peripheral vascular resistance. In patients with mild to moderate hypertension, moxonidine reduces blood pressure (BP) as effectively as most first-line antihypertensives when used as monotherapy and is also an effective adjunctive therapy in combination with other antihypertensive agents. It improves the metabolic profile in patients with hypertension and diabetes mellitus or impaired glucose tolerance, is well tolerated, has a low potential for drug interactions and may be administered once daily in most patients. Moxonidine is a good option in the treatment of patients with mild to moderate hypertension, particularly as adjunctive therapy in patients with the metabolic syndrome.

Rilmenidine (brand names Albarel, Hyperium, Iterium and Tenaxum) is an imidazoline derivative used for the treatment of hypertension. Rilmenidine, an oxazoline compound with antihypertensive properties, acts on both medullary and peripheral vasomotor structures. Rilmenidine shows greater selectivity for imidazoline receptors than for cerebral alpha2-adrenergic receptors, distinguishing it from reference alpha2-agonists. Rilmenidine is as effective in monotherapy as all other first line classes of drugs, including diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, and calcium antagonists. It is well tolerated and can be taken in combination for greater efficacy. Sedation and dry mouth are not prominent side effects and withdrawal hypertension is not seen when treatment is stopped abruptly. In addition to a reduction in blood pressure, Rilmenidine has been shown to improve glucose tolerance, lipid risk factors, and insulin sensitivity.