Amidapsone (aminoureidosulfone) is an urea analog of dapsone used in treatment of herpesvirus caused Marek's diseases.

Alphameprodine (ACSCN 9604) is an opioid analgesic classified by the United States Drug Enforcement Administration under Schedule I of illegal substances. The stereoisomer betameprodine is similarly classified, however alphameprodine is more widely used (both are referred to as Meprodine). Alphameprodine is a structural analogue of meperidine. It exerts physiological effects characteristic of opioids, such as analgesia, euphoria and sedation, as well as itching, nausea, and respiratory depression.

Dimenoxadol is an opioid analgesic which produces typical opioid effects such as analgesia and sedation. It is structurally similar to methadone and is a benzilic acid derivative. In the United States it is classified as a Schedule I controlled drug.

Bisfentidine (DA-5047), a histamine-2 receptor antagonist was studied for the treatment of colds and gingivitis.

Paliroden is an orally active drug that activates the synthesis of endogenous neurotrophins or nerve growth factors. Paliroden was investigated in phase II clinical trial in patients with Alzheimer's disease and to evaluate its effect on 18F-Dopa PET imaging in patients with Parkinson's disease. The further development of paliroden was discontinued due to its insufficient efficacy.

Felipyrine is a 1-aryl-2-pyrrolidinone derivative exerting anti-inflammatory activity.