Fluorfenidine F-18 is a radionucleotide used in positron emission tomography (PET) imaging procedures.

Teglarinad (also known as GMX1777) is a prodrug of GMX1778 and is an inhibitor of nicotinamide phosphoribosyl transferase (NAMPT). It is known that NAMPT involves in NAD(+) biosynthesis, which serves as an important substrate for proteins involved in DNA repair. Teglarinad was evaluated in two human head and neck cancer models in combination with radiotherapy. It was shown that the combining GMX1777 with pemetrexed was an effective new therapeutic strategy to treat nonsquamous non-small cell lung carcinoma (NSCLC). In addition, the drug participated in clinical trial phase I/II in combination with temozolomide for the treatment of metastatic melanoma, however, this study was terminated due to financial constraints.

Guanoctine was studied as an antihypertensive agent.

Guancydine, an antihypertensive agent which anti-angiotensin effect was not observed.

Zaltidine (CP-57,361) is a guanidinothiazolylimidazole compound which is a highly specific H2-receptor antagonist. It potently inhibits gastric acid secretion. Zaltidine appears to be an effective treatment of duodenal ulcer in human studies. However, the incidence of hepatic damage (8%) seems higher than with commonly used H2-receptor antagonists.

Tuvatidine (HUK 978) is a potent H2-antagonist. HUK 978 was shown to be devoid of activity at the histamine H1-receptor, the muscarinic receptor and the alpha and beta-adrenergic receptors. In both the guinea-pig gastric mucosa preparation and the rat perfused stomach model, HUK 978 was a powerful inhibitor of acid secretion. HUK 978 is a highly specific H2-antagonist and inhibits acid secretion for longer periods than other competitive compounds.