Imazodan, a phosphodiesterase III inhibitor was developed by Parke-Davis to treat heart failure and ischemic heart disorders. However, the study of this drug was discontinued.

Mariptiline is an antidepressant compound.

Delmadinone is a steroid with progestogenic, anti-androgenic and weak glucocorticoid action, synthesized in Syntex S.A. Acetate ester of delmadinone is used in veterinary under tradenames Tardak for cats and dogs for the treatment of excessive or aberrant sexual behaviour, including vagrancy, for the relief of prostatic hypertrophy, circum-anal tumors and for the treatment of certain forms of aggressiveness, nervousness, epileptiform seizures and corticosteroid-resistant pruritus. Delmadinone acetate blocks androgen receptors inhibit 5-reductase, which catalyzes the transformation of testosterone to the more potent androgen 5-dihydrotestosterone and decreases the production of testosterone by inhibiting gonadotropin release.

Levonantradol is a synthetic cannabinoid analogue of delta (9)-tetrahydrocannabinol (delta(9)-THC) administered intramuscularly. It has antiemetic and anti-analgesic properties. Although its precise mechanism of action is unknown, levonantradol appears to bind and activate the cannabinoid receptors CB1 and/or CB2. Antiemetic effect of levonantradol significantly superior to chlorpromazine. However, its adverse central effects limit its utility. The main adverse events are drowsiness and dizziness. Levonantradol, administered intramuscularly to the patients suffering from postoperative pain, manifested significant analgesic efficacy. Analgesia persisted for more than 6 h with the 2.5 and 3 mg doses of levonantradol. Drowsiness was frequent but few other psychoactive effects were reported.

Tepirindole (also known as HR-592), an indole derivative has a high affinity for DA, 5-HT and NE receptors but has little properties to cause catalepsy. Animal experiments have shown that this compound could alleviate the adverse effect of neuroleptics such as haloperidol. Information about the current development of tepirindole is not available.

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.

Etazolate (EHT-0202) is a selective, positive GABAA receptor modulator has completed phase II clinical trials in patients with Alzheimer's disease. It is also a selective phosphodiesterase-4 inhibitor that is specific for cAMP. Etazolate showed anxiolytic and antidepressant activity and could be useful in managing post-traumatic stress disorder.

Etintidine is a potent competitive antagonist of histamine H2-receptors. It has a low level of antiandrogenic activity. Etintidine was being investigated in the treatment of peptic ulcer, however, its development has been discontinued.

Tomelukast (previously known as LY171883), an orally active antagonist of the CysLT1 receptor (leukotriene D4), which was investigated to treat asthma, but this study was discontinued because of adverse gastrointestinal effect.