Rivenprost (ONO-4819) is a potent and selective EP4 receptor agonist. This compound can increase bone formation by stimulating osteoblast differentiation and function, possibly by modulating mesenchymal cell differentiation. Rivenprost has also been studied for its potential to prevent bone loss (in osteoporosis) and stabilize bone implants. Combined with risedronate, rivenprost may be an effective treatment for osteoporosis. A phase II study evaluating rivenprost in ulcerative colitis was terminated in 2009.

Fenmetramide is an antidepressant drug.

Norlevorphanol is the levo-isomer of 3-hydroxymorphinan (morphinan-3-ol). It is is an opioid analgesic of the morphinan family. Norlevorphanol is a Schedule I controlled substance (opiate).

Cromakalim is an ATP-sensitive potassium (KATP) channel opener, which was studied for the treatment of gastric ulcer, hypertension and preventing a cardiomyopathy. But the development of this drug was discontinued due to heart lesions found in monkey chronic toxicity studies.

Sanguinarine is an extract of the bloodroot plant Sanguinaria canadensis, a member of the poppy family. It is an inhibitor of protein phosphatases PP1, PP2C and PP2B in vitro. Also inhibits mitogen-activated protein kinase phosphatase-1 (MKP-1) and other enzymes. Sanguinarine exerts a protective effect in cerebral ischemia, and this effect is associated with its anti-inflammatory and anti-apoptotic properties. It was clinically tested as an agent against gingivitis and tooth plaques.