H2 antagonists, sometimes referred to as H2RAs and also called H2 blockers, are a class of medications that block the action of histamine at the histamine H2 receptors of the parietal cells in the stomach. This decreases the production of stomach acid. H2 antagonists can be used in the treatment of dyspepsia, peptic ulcers and gastroesophageal reflux disease. They have been surpassed by proton pump inhibitors (PPIs). The PPI omeprazole was found to be more effective at both healing and alleviating symptoms of ulcers and reflux oesophagitis than the H2 blockers ranitidine and cimetidine.
An International Nonproprietary Name (INN) is an official generic and nonproprietary name given to a pharmaceutical substance or an active ingredient. INNs are intended to make communication more precise by providing a unique standard name for each active ingredient, to avoid prescribing errors. The INN system was initiated by the World Health Organization (WHO) in 1953.
Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers.
Ranitidine, previously sold under the brand name Zantac among others, is a medication used to decrease stomach acid production. It was commonly used in treatment of peptic ulcer disease, gastroesophageal reflux disease, and Zollinger–Ellison syndrome. It can be given by mouth, injection into a muscle, or injection into a vein.
Etoperidone, associated with several brand names, is an atypical antidepressant which was developed in the 1970s and either is no longer marketed or was never marketed. It is a phenylpiperazine related to trazodone and nefazodone in chemical structure and is a serotonin antagonist and reuptake inhibitor (SARI) similarly to them.
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic drug that can be bought without a prescription and provides relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects. Antihistamines are usually for short-term treatment. Chronic allergies increase the risk of health problems which antihistamines might not treat, including asthma, sinusitis, and lower respiratory tract infection. Consultation of a medical professional is recommended for those who intend to take antihistamines for longer-term use.
The orexin receptor (also referred to as the hypocretin receptor) is a G-protein-coupled receptor that binds the neuropeptide orexin. There are two variants, OX1 and OX2, each encoded by a different gene (HCRTR1, HCRTR2).
Casopitant (INNTooltip International Nonproprietary Name), former tentative trade names Rezonic (U.S.) and Zunrisa (Europe), is an NK1 receptor antagonist which was undergoing research for the treatment of chemotherapy-induced nausea and vomiting. It was under development by GlaxoSmithKline. In July 2008, the company filed a marketing authorisation application with the European Medicines Agency. The application was withdrawn and development was discontinued in September 2009 because GlaxoSmithKline decided that further safety assessment was necessary. However, a 2022 review listed casopitant as under development as a potential novel antidepressant for the treatment of major depressive disorder, with a phase 2 clinical trial having been completed.
Nemonapride, also previously known as emonapride and sold under the brand name Emilace, is an atypical antipsychotic which is used in the treatment of schizophrenia. It is taken by mouth.
Vedaclidine (INN, codenamed LY-297,802, NNC 11-1053) is an experimental analgesic drug which acts as a mixed agonist–antagonist at muscarinic acetylcholine receptors, being a potent and selective agonist for the M1 and M4 subtypes, yet an antagonist at the M2, M3 and M5 subtypes. It is orally active and an effective analgesic over 3× the potency of morphine, with side effects such as salivation and tremor only occurring at many times the effective analgesic dose. Human trials showed little potential for development of dependence or abuse, and research is continuing into possible clinical application in the treatment of neuropathic pain and cancer pain relief.
Vestipitant (INN) is a drug developed by GlaxoSmithKline which acts as a selective antagonist for the NK1 receptor. It is under development as a potential antiemetic and anxiolytic drug, and as a treatment for tinnitus and insomnia.
Intepirdine (INN; developmental codes SB-742457, RVT-101) is a selective 5-HT6 receptor antagonist with potential cognition, memory, and learning-enhancing effects. It was under development by GlaxoSmithKline for the treatment of Alzheimer's disease and demonstrated some preliminary efficacy in phase II clinical trials. GSK chose not to continue development and sold the rights to Axovant Sciences for $5 million in December 2014.
Tums (stylized as TUMS) is an antacid made of sucrose (table sugar) and calcium carbonate (CaCO3) manufactured by Haleon in St. Louis, Missouri, US. They are also available in a sugar-free version. It is an over-the-counter drug, available at many retail stores, including drug stores, grocery stores and mass merchandisers. It provides relief from heartburn and indigestion ("sour stomach").
Epelsiban is an orally bioavailable drug which acts as a selective and potent oxytocin receptor antagonist. It was initially developed by GlaxoSmithKline (GSK) for the treatment of premature ejaculation in men and then as an agent to enhance embryo or blastocyst implantation in women undergoing embryo or blastocyst transfer associated with in vitro fertilization (IVF)., and was also investigated for use in the treatment of adenomyosis.
Clorotepine, also known as octoclothepin or octoclothepine, is an antipsychotic of the tricyclic group which was derived from perathiepin in 1965 and marketed in the Czech Republic by Spofa in or around 1971 for the treatment of schizophrenic psychosis.
There are several classes of drugs for acid-related disorders, such as dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD), or laryngopharyngeal reflux.
Serlopitant (INN, codenamed VPD-737) is a drug which acts as an NK1 receptor antagonist. It was assessed in clinical trials for the treatment of urinary incontinence and overactive bladder, but while it was superior to placebo it provided no advantage over existing approved drugs, and was not approved for further development for this indication. Serlopitant is now undergoing clinical trials for the treatment of chronic pruritus (itch)
Remeglurant is a drug which acts as a selective antagonist of the mGlu5 receptor. It is under development by Merz Pharmaceuticals for the treatment of drug-induced dyskinesia but no development has been reported since at least 2016.
Sufotidine (INN, USAN, codenamed AH25352) is a long-acting competitive H2 receptor antagonist which was under development as an antiulcerant by Glaxo (now GlaxoSmithKline). It was planned to be a follow-up compound to ranitidine (Zantac). When taken in doses of 600 mg twice daily it induced virtually 24-hour gastric anacidity thus closely resembling the antisecretory effect of the proton pump inhibitor omeprazole. Its development was terminated in 1989 from phase III clinical trials based on the appearance of carcinoid tumors in long-term toxicity testing in rodents.
Rolapitant (INN, trade name Varubivə-ROO-bee in the US and Varuby in the European Union) is a drug originally developed by Schering-Plough and licensed for clinical development by Tesaro, which acts as a selective NK1 receptor antagonist (antagonist for the NK1 receptor). It has been approved as a medication for the treatment of chemotherapy-induced nausea and vomiting (CINV) after clinical trials showed it to have similar or improved efficacy and some improvement in safety over existing drugs for this application.
