Ciproquazone (SL-573) is a non-steroidal anti-inflammatory drug, a derivative of quinazolinone, discovered by Sumimoto Chemical Co. in the late 1970s. Ciproquazone acts as a reversible inhibitor of prostaglandin synthetase. In animal models, ciproquazone demonstrated antipyretic, analgesic and anti-inflammatory activity. The drug was evaluated in a clinical in acute purulent diseases in the field of orodental surgery.

Pytamine is a nitrosamine derivative patented by Hercules Powder Co. as antioxidants, stabilizers, rubber additives, insecticides, fungicides, bactericides, and pharmaceutical intermediates. In preclinical trials Pytamine shows potent psychotropic effects associated modulation of GABAA receptors.

Efipladib is an inhibitor of cytosolic phospholipase A2 alpha both in vitro and in vivo. It is able to relieve inflammatory pain in animal model. Additionally, efipladib exerts antitumor potential. Efipladib was in clinical trials for the treatment of asthma and arthritis however its development has been discontinued.

Vanitiolide is a choleretic agent.

Fosquidone (also known as GR63178A), a pentacyclic pyrroloquinone that was developed as an anticancer agent. Fosquidone participated in phase II clinical trial for the treatment of patients with colorectal, renal and non-small cell lung cancer. However, the drug didn’t show significant antitumor activity. The further development of this drug was discontinued.

Fospirate is an organophosphorus insecticide used in veterinary as an anthelmintic agent.

Flurocitabine is an anti-metabolite that was developed by Hoffmann-La Roche for the treatment of cancer. The drug is metabolized to 2 biologically active substances, AFC (1-beta-D-arabinofuranosyl-5-fluorocytosine) and AFU (arabinofuranosyl-5-fluorouracil). Flurocitabine was tested against stomach cancer, pancreatic cancer, small cell lung cancer and AML, however, the development was terminated in the early phases.

Fluprofen was invented as an analgesic and anti-inflammatory agent. However, information about the current use of this drug is not available.

Pipequaline (PK-8165, 2-phenyl-4[2-(4-piperidinyl) ethyl]quinoline) is a benzodiazepine receptor partial agonist.