Tilozepine is a thienobenzazepine derivative patented Wander A.-G. as hypnotic, sedative, antipsychotic, and muscle relaxant. Tilozepine acts as a non-selective antagonist of dopamine receptors and shows neuroleptic activity in animal models.

Sulmarin is a water-soluble coumarin derivative with vitamin P activity. In preclinical models Sulmarin facilitates excitatory transmission from parasympathetic fibers to the gastric musculature, increasing acetylcholine release. Sulmarin reduced the tone of isolated calf coronary arteries and also inhibited the contractile response of the arteries to angiotensin II amide (Hypertensin).

Sulfasymazine is a sulfanilamide derivative patented by American Cyanamid Co. as antibacterial agents for Staphylococcus and Streptococcus infections. In preclinical models, Sulfasymazine shows activity on a dosage basis ranged from 2- to 10-fold that of sulfisoxazole, and from 1/3 to equal on a blood-level basis, but was not as potent as sulfadiazine.

Sofinicline is a selective agonist of the a4b2 subtype of nAChR. It is under development by Abbott Laboratories in collaboration with NeuroSearch. It is produced as a capsule in doses of 1, 2 or 4 mg. Sofinicline is a full agonist of the a4b2 nAChR. It has high binding affinity, ~ 0.1 nM, for this receptor. Sofinicline is orally active and is metabolized hepatically. Sofinicline has been used in trials studying the treatment of ADHD, neuralgia, diabetic neuropathies, diabetic polyneuropathy, and diabetic neuropathic pain, among others.

Soraprazan (remofuscin), a potassium-competitive acid blocker (P-CAB; formerly called an acid pump antagonist [APA]), is being developed by Katairo GmbH for the treatment of Stargardt's disease and dry age-related macular degeneration (AMD). Clinical development is underway for Stargardt's disease and dry age-related macular degeneration in the Netherlands and Germany. On 13 November 2013, orphan designation was granted by the European Commission to Katairo GmbH, Germany, for soraprazan for the treatment of Stargardt’s disease. Soraprazan is a a highly potent reversible, and fast-acting inhibitor of gastric H,K-ATPase. Soraprazan shows immediate inhibition of acid secretion in various in vitro models and in vivo and was found to be more than 2000-fold selective for H,K-ATPase over Na,K- and Ca-ATPases.

Nabitan is a synthetic cannabinoid analog of dronabinol with antiemetic and analgesic effects. Nabitan is not currently used in medicine as dronabinol or nabilone are felt to be more useful for most conditions, however, it is sometimes used in research into the potential therapeutic applications of cannabinoids.

Mitemcinal (GM-611), an erythromycin-derived prokinetic agent, was developed by Chuga as an agonist of the motilin receptor. Mitemcinal acts by a novel mechanism whereby it stimulates and promotes peristalsis in the stomach and other segments of the gastrointestinal tract. This drug was studied as a potential treatment for gastric motility disorder, as well as reflux esophagitis, non-ulcer dyspepsia, and diabetic gastroparesis. Mitemcinal was involved in phase II clinical trials in Patients with diabetic gastroparesis. Although gastroparetic symptoms improved with both mitemcinal and placebo, the prominent placebo effect was not statistically exceeded by mitemcinal. That is why the development of this drug has stalled. In addition, mitemcinal has been studied in phase II for the treatment of irritable bowel syndrome, but this study was also discontinued.

Mezilamine is a dopamine antagonist, it blocks presynaptic but stimulates postsynaptic alpha-adrenoceptors. Potential antipsychotic drug.

Methastyridone (MK-202), a centrally acting stimulant, was studied with chronic anergic schizophrenics. Information about the current use of this compound is not available.