Benactyzine, an anticholinergic drug, had been used as an antidepressant in the treatment of depression and associated anxiety. It is no longer used in medicine due to its ineffectiveness but is widely used in scientific research. Benactyzine is a muscarinic antagonist which also inhibits the nicotinic acetylcholine receptor.

Tubocurarine, a naturally occurring alkaloid, is used to treat smoking withdrawl syndrom. Tubocurarine, the chief alkaloid in tobacco products, binds stereo-selectively to nicotinic-cholinergic receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system effects are believed to be the basis of Tubocurarine's positively reinforcing properties. A stimulating effect is exerted mainly in the cortex via the locus ceruleus and a reward effect is exerted in the limbic system. At low doses the stimulant effects predominate while at high doses the reward effects predominate. Intermittent intravenous administration of Tubocurarine activates neurohormonal pathways, releasing acetylcholine, norepinephrine, dopamine, serotonin, vasopressin, beta-endorphin, growth hormone, and ACTH. Tubocurarine competes with acetylcholine for post-synaptic nicotinic NM receptors and blocks them.

Hydrastinine is a synthetic alkaloid prepared by various processes from either hydrastine, berberine, or narcotine. It exerts a strong stimulating action on the uterus of all species studied, including human. Hydrastinine and the closely related alkaloid cotarnine have been employed as hemostatics, particularly in abnormal uterine conditions. In the non-pregnant animal, hydrastinine in doses of 10 mg. depressed both tonus and activity, even after the section of the hypogastric. In the pregnant cat, it caused the uterus to contract. A stimulant action was also noted in the non-pregnant animal if nicotine were administered prior to hydrastinine. The rabbit uterus in situ was strongly contracted. Laidlaw believed that hydrastinine acted on the uterus both directly on the smooth muscle and also through its sympathetic innervation. Repeated administration of large doses for a period of time resulted in greatly increased amplitude of contractions which persisted after removal of the drug. The drug was patented by Bayer as a haemostatic drug during the 1910s.

Melatonin (5-methoxy N-acetyltryptamine) is a hormone synthesized and released from the pineal gland at night, which acts on specific high affinity G-protein coupled receptors to regulate various aspects of physiology and behaviour, including circadian and seasonal responses, and some retinal, cardiovascular and immunological functions. Melatonin is also made synthetically and available without a prescription as an over-the-counter (OTC) dietary supplement in the U.S. Melatonin supplementation has many uses, however, it has been widely studied for treatment of jet lag and sleep disorders. Parents may consider using melatonin to help their child who has a trouble falling asleep. A medical professional should always evaluate insomnia or other sleeping disorders in children. Additionally, melatonin has been shown to protect against oxidative stress in various, highly divergent experimental systems. There are many reasons for its remarkable protective potential. In mammals, melatonin binds to a number of receptor subtypes including high-affinity (MT1 and MT2) and low-affinity (MT3, nuclear orphan receptors) binding sites, which are distributed throughout the central nervous system and periphery.

Domperidone is a peripherally selective D2 receptor antagonist. It acts as an antiemetic and a prokinetic agent through its effects on the chemoreceptor trigger zone and motor function of the stomach and small intestine. Domperidone was not approved in USA due to risks of cardiac arrhythmias, cardiac arrest, and sudden death, but is available in other countries. However, FDA allows access to Domperidone through an expanded access investigational new drug application (IND) to patients with gastroesophageal reflux disease with upper GI symptoms, gastroparesis, and chronic constipation. As an “off-label” use, domperidone is prescribed to breastfeeding women to enhance their milk production.

Nitenpyram is a neonicotinoid, a neurotoxin that blocks neural messages and used in agriculture and veterinary medicine to kill external parasites of pets. Imidacloprid act as agonists at the insect nicotinic acetylcholine receptor (nAChR). The botanical insecticide nicotine acts at the same target without the neonicotinoid level of effectiveness or safety. Fundamental differences between the nAChRs of insects and mammals confer remarkable selectivity for the neonicotinoids. Whereas ionized nicotine binds at an anionic subsite in the mammalian nAChR, the negatively tipped ("magic" nitro or cyano) neonicotinoids interact with a proposed unique subsite consisting of cationic amino acid residue(s) in the insect nAChR. Nitenpyram was introduced into the United States in 1994 as a veterinary flea control treatment, structural pest and crop insecticide, and seed treatment. It has been used orally in dogs, cats, and some wildlife species for over 10 years. After ingestion, it begins killing adult fleas within 30 minutes, and effects continue for up to 48 hours. Though nitenpyram is used to kill adult fleas quickly on an infected animal, it does not kill insect eggs and has no long-term activity. Thus, it is not effective as a long-term flea preventative; however, it can be repeatedly applied over the course of several days to eradicate a single instance of infestation. Nitenpyram can be combined with a longer-term flea preventative like fipronil or lufenuron to prevent reinfestation. Neonicotinoids for veterinary use are considered to have a low order of toxicity for domestic animals and there are no reports of nitenpyram intoxication.

Elobixibat is the first in class ileal bile acid transporter (IBAT) inhibitor. IBAT inhibitors block ileal absorption of bile acids by: (1) interrupting the enterohepatic circulation of bile resulting in a fall in serum cholesterol and (2) increasing the delivery of bile acids into the colon. Elobixibat stimulates both motor and secretory functions in the colon. Elobixibat is approved in Japan for the treatment of chronic constipation. Elobixibat has potential benefit in the treatment of non-alcoholic steatohepatitis.

Gabexate is a synthetic protease inhibitor, was shown to be effective in treating patients with sepsis-associated disseminated intravascular coagulation in which tumor necrosis factor-alpha (TNF-alpha) plays a critical role. Gabexate mesylate is a drug marketed only in Italy and Japan and it is considered an essential drug in the treatment of acute pancreatitis. Gabexate is marketed under the brand name REMINARON among others in Japan. It relieves inflammatory symptoms in the pancreas by inhibiting various enzymes. It also improves organ disorders and bleeding tendency caused by blood clots in blood vessels by inhibiting blood coagulation. It is usually used to treat acute pancreatitis with deviation of proteolytic enzymes (such as trypsin, kallikrein and plasmin), acute exacerbation of chronic recurrent pancreatitis, acute pancreatitis after surgery and disseminated intravascular coagulation.

Evocalcet (MT-4580, KHK7580) is an allosteric calcium-sensing receptor agonist. Evocalcet directly acts on calcium receptors on parathyroid cells to suppress synthesis and secretion of parathyroid hormone (PTH), and it consequently decreases serum PTH and serum calcium. ORKEDIA® TABLETS (generic name: evocalcet, code name: KHK7580) has been listed on the National Health Insurance (NHI) Drug Price List and launched for the treatment of secondary hyperparathyroidism in patients on maintenance dialysis in Japan.

Azasetron is an antiemetic drug. It acts as serotonin 3 receptor antagonist. It is currently used to prevent nausea and vomiting caused by cancer chemotherapy (including cisplatin chemotherapy). Also it was demonstrated that azasetron has potent antimitogenic and apoptotic effect on cancer cell line. It was preclinically tested to treat cocaine abuse.