Fadolmidine (MPV 2426) is an alpha2-adrenoceptor agonist. Fadolmidine displayed high affinity and full agonist efficacy at all three human alpha2-adrenoceptor subtypes (A, B and C). Various preclinical models of pain have been employed and have demonstrated fadolmidine potential as an analgesic, including its potential for use in neuropathies and post-operative pain. A Phase II clinical trial successfully demonstrated that intrathecal fadolmidine, in combination with bupivacaine, produced analgesic effects compared to bupivacaine alone in bunionectomy patients.

FIDUXOSIN is a selective alpha1-adrenoceptor antagonist with higher affinity for alpha1A-adrenoceptors and for alpha1D-adrenoceptors than for alpha1B-adrenoceptors. It was in clinical trials for the treatment of benign prostatic hyperplasia.

Dabuzalgron is an orally active and selective alpha1A/1L-adrenoreceptor partial agonist, developed by Roche. In anesthetized micropigs and rabbits, dabuzalgron produced non-selective, dose-dependent increases in intraurethral and arterial blood pressures. In conscious micropigs, both agents produced dose-dependent increases in urethral tension. Dabuzalgron was investigated in a clinical study in women with stress urinary incontinence (SUI). It was demonstrated that 1.5 mg of the drug administered twice daily lead to a significantly lower mean weekly number of SUI episodes with little or no cardiovascular effect. Despite positive results, no development of the drug was reported by Roche.

Nolomirole (CHF1035) is an orally active, selective dopamine agonist, primarily activating DA2- and alpha2 receptors, thereby inhibiting norepinephrine release, which may be beneficial in heart failure. Nolomirole is able to attenuate the heart failure signs in the monocrotaline-induced congestive heart failure. CHF1035 is a mixture of two enantiomers, CHF1800 (+) and CHF1810 (-). CHF1035 and its metabolite CHF1024 significantly decreased the IOP in rabbits, and are potential novel IOP lowering agents. Especially, CHF1035 produced a substantial decrease in IOP for a prolonged period of time, and thus may prove useful in glaucoma therapy. Nolomirole is a pre-synaptic stimulator of DA2-dopaminergic and α2-adrenergic receptors in peripheral sympathetic nerve endings. These receptors act as a negative feedback mechanism, inhibiting norepinephrine secretion. In early phase clinical studies lasting 1–3 months, nolomirole reduced peripheral systemic resistance and 24 hour blood pressure and increased cardiac output. In a study of 29 patients with heart failure, followed for 10 days, a reduction in plasma norepinephrine was demonstrated. In spite of the fact that Nolomirole was in clinical trials for the treatment of heart failure, its development was discontinued.

Etiocholanone is an androstane neurosteroid. Etiocholanone potentiates GABA-A receptor currents and exerts anticolvunsant properties in rodents. Etiocholanolone demostrates pyrogenic properties.

Pregnanediol is a chief steroid metabolite of progesterone that is biologically inactive and occurs as pregnanediol glucuronate in the urine. Pregnanediol has two hydroxyl groups, at 3-alpha and 20-alpha. A test can be done to measure the amount of pregnanediol in urine. The urine test offers an indirect way to measure progesterone levels in the body. It is a standard in the colorimetric determination of urinary pregnanediol in clinical laboratories.

Napamezole [WIN 51181] is a potent alpha-2 adrenergic receptor antagonist and a selective inhibitor of 5-hydroxytryptamine re-uptake in vitro. Napamezole was at the phase I stage of development with Sanofi Winthrop (formerly known as Sterling Drug before it was purchased by Sanofi) in the USA as a treatment for depression. The alpha adrenergic antagonist activity of napamezole was determined in vitro in rat brain receptor binding assay using [3H]clonidine and [3H]prazosin for alpha-2 and alpha-1 receptors, respectively. The Ki values for napamezole were 28 nM (alpha-2) and 93 nM (alpha-1).

Butanserin is the potent and selective alpha 1-adrenoceptor antagonist.

Spiroxatrine is a drug which acts as a selective antagonist at both the 5-HT1A receptor and the α2 adrenergic receptor. Spiroxatrine was identified as a moderately potent but non-selective agonist at the human nociceptin/orphanin FQ receptor, ORL1

Coumazoline is a vasoconstrictor developed as a nasal decongestant by a French corporation Labez. Intravenous administration of the compound to dogs lead to a marked and prolonged drop in the temperature of the gingival mucosa. In rats, coumazoline caused slowing of the dye diffusion on the surface of the skin. The compound did not influence the ciliary motility, as was measured on an isolated guinea pig trachea.