Napitane [A 75200, ABT 200] is a norepinephrine uptake inhibitor and α2 adrenoceptor antagonist. It was undergoing clinical trials with Abbott in the USA as a treatment for depression. However it was discontinued later. Napitane is a potent alpha 2-adrenoceptor antagonist (Ki = 1.2 nM) with modest norepinephrine uptake-blocking activity (IC50 = 841 nM).

Imiloxan is a highly selective alpha2B adrenoceptor antagonist and was developed for depression in the 1980s. In Phase 1 clinical trials imiloxan dosing led to hypersensitivity reactions; the molecule's development was discontinued.

Indanidine is a selective and effective α2-antagonist, α1-partial agonist patented by pharmaceutical company Siegfried A.-G as a low toxic compound with direct hypotensive action. Indanidine does not penetrate the blood-brain barrier, does not induce drug-metabolizing enzymes in the liver, does not cause behavioral changes.

Tolboxane is an alpha-adrenergic blocking drug. It is a product of arachidonic acid oxidation. Tolboxane is a tranquilizer. It influences atherosclerosis pathogenesis.

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.