Enprostil, a derivative of heptadienoic acid, is a prostaglandin E2 agonist. It is effective in the treatment of patients with duodenal or gastric ulcers.

Phloroglucinol is an organic compound that is used in the synthesis of pharmaceuticals and explosives. Phloroglucinol is a phenol derivative with antispasmodic properties that is used primarily as a laboratory reagent. The mechanism of action is most likely based on the direct inhibition of the voltage-dependent calcium channels of smooth muscle; however, the modulation of prostaglandin or nitric oxide release has also been suggested. Although it has long been used in clinical practice as an antispasmodic for painful urogenital and gastrointestinal conditions, in an early study on anesthetized rats, phloroglucinol was found to be inactive toward the contraction of the duodenum, ileum and colon. Similarly, in anesthetized dogs, phloroglucinol plus trimethyl-phloroglucinol failed to antagonize acetylcholine-induced contraction of the colon. In parallel with animal studies, phloroglucinol plus trimethyl-phloroglucinol had no clear effects in humans on ascending and sigmoid colon hypermotility evoked by neostigmine. However in Irritable bowel syndrome (IBS) patients iv phloroglucinol effectively reduced postprandial rectosigmoid motility increases after a test meal, compared to placebo. In another study of IBS patients, phloroglucinol inhibited phasic contractions provoked by intrarectally injected glycerol, but it did not modify colonic tone. In an open-label study of 100 IBS patients selected according to the Rome II criteria, po 50 mg phloroglucinol was administered three times daily for two months. The 68 patients who completed the study reported significant improvement in abdominal pain, frequency of stools per day, urgency, passage of mucus per the rectum, sense of incomplete defecation and bloating. Nevertheless, straining was unchanged. Further, a multicenter, randomized, double-blind, placebo-controlled trial examined the effects of phloroglucinol/trimethylphloroglucinol (62.2 mg P plus 80 mg TMP three times daily) or placebo for 7 d in 307 IBS patients diagnosed using the Rome II criteria. The relative decrease in pain intensity and the responder rate were significantly higher in the P/TMP-treated group, compared to the placebo-treated group. Further, the treatment effect persisted up to the 7th day in a higher percentage of patients treated with P/TMP than in those treated with placebo.

Broxyquinoline is an anti-infective agent. It exerts activity against fungi and protozoa. Broxyquinoline (Intestopan) has been used in the treatment of diarrhoeas of different aetiology. Broxyquinoline is able to promote neovascularization.

Acetarsone is a pentavalent arsenical compound with antiprotozoal and antihelmintic properties. It was first discovered in 1921 at Pasteur Institute by Ernest Fourneau, and sold under the brand name Stovarsol (fourneau is the French word for stove). Before stovarsol was used in the treatment of congenital syphilis, it had already been used in other diseases : amoebiasis, acquired syphilis, yaws, trypanosomiasis and malaria, and a formidable list of toxic manifestations can be compiled from the literature. Bender (I927) recorded six cases of poisoning with malaise, fever, cedema, jaundice, diarrhoea, albuminuria, bronchitis, coryza and skin troubles, such as diffuse erythema, dryness and pruritus. Of 232 cases of amoebiasis treated by Brown (I935) without a death, thirteen (5.6%) had toxic erythemata, some of them so severe as to amount to exfoliative dermatitis. Although its mechanism of action is not fully known, acetarsone may bind to protein-containing sulfhydryl groups located in the parasite, thereby forming lethal As-S bonds. This may prevent their functioning and eventually kill the parasite.

Nifurzide, a synthetic antimicrobial agent of the nitrofuran group. The MICs were excellent for Campylobacter spp. (97 strains); slightly higher for Shigella spp. (50 strains) and Aeromonas spp. (22 strains); and highest for Salmonella spp. (100 strains) and Yersinia enterocolitica. At low concentrations of nifurzide, the growth rate of the Escherichia coli cultures decreased, and elongated, nonseptate cells appeared. At high concentrations, complete growth inhibition occurred, accompanied by a rather strong bactericidal effect, but the appearance of the cells was normal; in particular, no bacteriolytic effect was observed. A very large number of antibiotic molecules were bound per bacterial cell. After cell disruption, similar amounts of nifurzide were found in the cytoplasm, cytoplasmic membranes, and cell wall, respectively. Nifurzide had no effect on a general infection, but significantly decreased the number of colony-forming germs in the digestive tract. It was rather insoluble in aqueous media, did not cross the intestinal barrier, and was not substantially metabolized in the intestine. The obnoxious side effects of other nitrofurans (induction of vomiting and inhibition of monoamine oxidase) were not observed with nifurzide, which makes it an interesting therapeutic agent against enteric infections.

Racecadotril (acetorphan) is an oral enkephalinase inhibitor for use in the treatment of acute diarrhea. Racecadotril reduces hypersecretion of water and electrolytes into the intestinal lumen, by preventing the degradation of endogenous enkephalins. Treatment with racecadotril reduces the incidence and duration of acute diarrhea and reduces diarrhea-associated symptoms compared with placebo in adults. Racecadotril treatment also results in significant reductions in stool output compared with placebo in infants and young children aged 2 months to 4 years with acute diarrhea. Both rotavirus-negative and rotavirus-positive infections appear to respond to treatment in the pediatric populations investigated for this infection. Racecadotril shows similar or slightly reduced efficacy to loperamide in the treatment of diarrhea in adults and children aged up to 10 years. However, in comparative trials, racecadotril was associated with fewer adverse events than loperamide, in particular, post-treatment constipation. Racecadotril is available in France (where it was first introduced in ~1990) and other European countries (including Germany, Italy, the UK, Spain and the Czech Republic) as well as most of South America and some South East Asian countries (including China, India and Thailand), but not in the United States.

This medicine promotes secretion of the bile and pancreatic juice, and accelerates flaccidity of the smooth muscle in the gastrointestinal tract (sphincter of hepatopancreatic ampulla etc.) to lower internal pressure of the gallbladder and bile duct. It improves the symptoms of the bile duct and pancreatic disease. It is usually used for improvement of cramp and bile secretion associated with cholelithiasis, cholecystitis, cholangitis, dyskinesia of the biliary tract or postcholecystectomy syndrome, or pain and gastrointestinal symptoms associated with chronic pancreatitis. Side effects are nausea, constipation, abdominal bloating, diarrhea, rash, itch, etc.

Moxaverine, a derivative of papaverine, is a phosphodiesterase inhibitor. Moxaverine has been studied in phase III of a clinical trial for the treatment of ocular blood flow in patients with age- related macular degeneration and primary open angle glaucoma. In addition, it has been studied in phase II of the clinical trial for the treatment of ischemia. This compound is prohibited by FEI (International Federation of equine).

Mitiglinide is a drug for the treatment of type 2 diabetes currently marked under tradename Glufast. Glufast® is available as the tablet for oral use, containing 5 mg or 10 mg of Mitiglinide calcium hydrate. The recommended dose is 10 mg three times daily just before each meal (within 5 minutes). Mitiglinide was approved by Pharmaceuticals and Medical Devices Agency of Japan (PMDA) on January 29, 2004, and is currently co-marketed in Japan by Kissei and Takeda. Mitiglinide is a rapid-acting insulin secretion-stimulating agent, its belongs to the meglitinide (glinide) class of blood glucose-lowering drugs. Mitiglinide is thought to stimulate insulin secretion by closing the ATP-sensitive K(+) (K(ATP)) channels in pancreatic beta-cells.