Paramethadione is an anticonvulsant in the oxazolidinedione class developed by the Abbott Laboratories, approved by the Food and Drug Administration in 1949 for the treatment of absence seizures, also called partial seizures. Paramethadione acts to reduce T-type calcium currents in thalamic neurons which has been proposed to underlie the 3-Hz spike-and-wave discharge seen on electroencephalogram (EEG) during absence seizures.

Quinacrine was initially developed as an anti-malarial drug marketed under the name Atabrine. Also it was approved for the teratment of ascites, however it was wothdrawn for both indication in 1995 and 2003, respectively. The drug is also used for the treatment of giardiasis, lupus, rheumatoid arthritis, refractory pulmonary effusion and pneumothorax, induce female sterilization etc. Proposed mechanisms of action include DNA intercalation interference with RNA transcription and translation, inhibition of succinate oxidation interference with electron transport, inhibition of cholinesterase, and inhibitor of phospholipase.

Mephobarbital us a barbiturate derivative used primary as an anticonvulsant, but also as a sedative and anxiolytic. Marketing of mephobarbital was discontinued in 2012.

Aconitine is an alkaloid found in the Aconitum species. Aconitine is a highly toxic cardiotoxin and neurotoxin. In China and other countries, the herbal extract containing aconitine was used for the treatment of pain in musculoskeletal disorders, however the safety margin between therapeutic analgesic effect of aconitine and its known cardiotoxic effect is so narrow that the treatment may cause poisoning and death. The mechanism of aconitine action is explained by its ability to activate voltage-dependent sodium-ion channels.

QUININE HYPOPHOSPHITE, a salt of quinine, was formerly used, along with the hypophosphites of sodium, potassium, calcium, and iron, in the treatment of phthisis and neurasthenic conditions.

Aminophenazone is a phenyl-pyrazolone derivative with potent analgesic and antipyretic properties. Aminophenazone has been used as salt or complexes, including topically as the salicylate. It was recommended for the treatment of a fever, neuralgia, myositis, acute rheumatism, arthritis, chorea. In 1999 the FDA suspended aminophenazone. The drug caused agranulocytosis. Some of the cases of agranulocytosis were fatal. Another reason for suspending this drug from the market was its ability to react with nitrite-containing food, thus forming carcinogenic nitrosamines. A breath test with 13C-labeled aminopyrine has been used as a non-invasive measure of cytochrome P-450 metabolic activity in liver function tests.

Antipyrine is an analgesic and antipyretic that has been given by mouth and as ear drops. It is often used in testing the effects of other drugs or diseases on drug-metabolizing enzymes in the liver. It inhibits cyclooxygenases and shows little anti-inflammatory activity. Like many old and approved substances after almost 100 years of use, antipyrine has been associated with some serious side effects, namely agranulocytosis and shock reactions.

Quinine ascorbate is a salt of antimalarial drug quinine and ascorbic acid (vitamin C). Ascorbate reduces the potency of quinolone-containing anti-malarial drugs. Quinine ascorbate was marketed as a component of over-the-counter smoking deterrent products but was not recognized as safe by the FDA regulation in 1993.

Flotufolastat F 18 (POSLUMA®) is an 18F-labelled radiohybrid (rh) prostate-specific membrane antigen (PSMA)-targeted imaging agent being developed by Blue Earth Diagnostics, a subsidiary of Bracco Imaging, for prostate cancer imaging. In May 2023, flotufolastat F 18 received its first approval in the USA as a radioactive diagnostic agent for positron emission tomography (PET) of PSMA positive lesions in men with prostate cancer with suspected metastasis who are candidates for initial definitive therapy or with suspected recurrence based on elevated serum prostate-specific antigen (PSA) level. Flotufolastat F 18 binds to PSMA (IC50 = 4.4 nM) expressed on cells, including prostate cancer cells, and is internalized. Prostate cancer cells usually overexpress PSMA. Fluorine-18 is a beta emitting radionuclide that can be detected using positron emission tomography.