Ciladopa, is a troponylpiperazine derivative and dopamine agonist that has been shown to influence dopaminergic mechanisms in animals. Preclinical pharmacological studies have suggested that it has antiparkinsonian activity similar to that of bromocriptine but without many of the troublesome side effects. Unfortunately in some clinical trials no significant differences was found among the treatment groups and placebo.

Desomorphine is the common name for 4,5--epoxy-17- methylmorphinan-3-ol or dihydrodesoxymorphine-D. It is an opioid analogue and morphine derivative in which the 6-hydroxyl group and the double bond at carbons 7 and 8 of morphine are reduced. Desomorphine can cross the blood–brain barrier, binding to opioid receptors, similar to the pharmacokinetic distribution of all phenanthrene-structured alkaloids. Taking Desomorphine causes euphoria as well as sedative and analgesic relief. In addition to its faster onset than other powerful painkillers drugs such as morphine, desomorphine also initiates less sedative effects and seems to have favorable postoperative results, such as reduced need for catheterization, less dizziness, and decreased vomiting incidence. In comparison with Morphine, Desomorphine is faster reduced. It follows that it has to be taken it more frequently to get the same effects. Furthermore, it causes side effects such as respiratory and gastrointestinal problems and increased blood pressure. In addition, Desomorphine’s withdrawal symptoms are up to three times longer than Morphine’s. This leads to the conclusion that Desomorphine is more addictive. At present, desomorphine is classified as a narcotic drug (DEA code number 9055) in Schedule I of the U.S. Controlled Substances Act and is listed as a controlled substance under the international Single Convention on Narcotic Drugs of 1961.

Bedoradrine (also known as KUR-1246 or MN-221), an ultra selective beta 2-adrenoceptor agonist, that participated in phase II clinical trials as an adjunct to standard therapy in the management of patients with acute exacerbation of asthma who did not respond to standard therapy. In addition, the drug was involved in trials for the treatment of preterm labor in obstetrical practice. Bedoradrine is also was studied in phase I of clinical trials for its use for treating chronic obstructive pulmonary disease, however, the efficacy for this disease was uncertain.

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

Etonitazene is a potent and selective mu-opioid agonist. It was developed in CIBA. Administration of etonitazene may induce respiratory depression, and therefor etonitazene is not used in humans. Etonitazene is explicitly listed as an illegal drug under UN convention and is illegal throughout the world.

Adoprazine (SVL-313) is a full 5-HT1A receptor agonist and full D2/3 receptor antagonist possessing characteristics of an atypical antipsychotic, representing a potential novel treatment for schizophrenia and bipolar disorder. This drug together with some others, e.g. Mazapertine succinate, PF-217830 was discontinued from clinical trials due to either non-optimal pharmacokinetic properties or insufficient therapeutical efficacy.

Ciprostene is a synthetic, chemically stable analog of prostacyclin (PGI2). In animal models, administration of ciprostene resulted in dose-dependent hypotension, tachycardia, and inhibition of ex vivo ADP-induced platelet aggregation. Ciprostene was evaluated in clinical trials in patients with peripheral vascular disease. It was found to reduce restenosis in patients with coronary artery disease undergoing therapeutic percutaneous transluminal coronary angioplasty.

Edaglitazone have a clear PPAR-gamma agonist profile, with predominant PPAR-gamma activity and little PPAR-alpha activity. Edaglitazone was reported to significantly improve insulin sensitivity and enhance the rate of glucose oxidation in both the presence and absence of insulin. Additional studies have shown that edaglitazone affects muscle glucose metabolism by additional mechanisms other than PPAR-gamma activation. Phase I clinical studies have revealed that edaglitazone is well-tolerated and capable of significantly improving glucose homeostasis. Edaglitazone had been in phase II clinical trials for the treatment if type 2 diabetes. However, this research has been discontinued.

ORG-28611 (SCH-900,111) is a potent cannabinoid receptor full agonist, developed by Organon International for treatment pain. In preclinical studies, Org 28611 exhibited high affinity for both CB1 and CB2 cannabinoid receptors, as determined by radioligand competition binding assays and rapidly metabolized by mouse and human hepatic microsomes and showed higher total levels in the brain compared to plasma. In clinical trials, Org 28611 does not provide enough sedation for outpatient surgical procedures, does not induce anterograde amnesia and causes undesirable subjective effects at higher doses. However, bolus doses up to 3 μ/kg (with maximum initial plasma concentrations of 24 ng/mL) or mean plasma levels up to 4 ng/mL are well tolerated and make it worthwhile to further explore the analgesic or antiemetic properties.

Dexlofexidine is an isomer “+“ of lofexidine, which is agonist of alpha 2-adrenoceptor, but in 10 times less potent than the other isomer, levlofexidine.