Edifolone (SC-35135) is a structurally unique class Ia antiarrhythmic agent. It acts as a sodium channel antagonist. Edifolone development has been discontinued.

Mozenavir is a non-peptidomimetic, water soluble, cyclic urea that is a selective inhibitor of HIV-1 protease. Mozenavir is active against the virus with the signature D30N nelfinavir resistance-associated mutation and the L90M mutants with decreased susceptibility to a number of other protease inhibitors. In a dose-ranging study assessing Mozenavir, in doses of 750 mg 3 times a day, 1250 mg twice daily, or 1250 mg 3 times a day, compared with standard doses of indinavir, both in combination with lamivudine and stavudine, plasma HIV-1 RNA levels were reduced to below 50 copies/mL in 75% to 80% of patients receiving Mozenavir-based treatment and in 70% of those receiving indinavir-based treatment. Mozenavir-based regimens were generally well tolerated. However, the virus was able to mount considerable resistance against this compound, which was not further developed, also because of poor oral bioavailability in humans and highly variable blood levels.

Altoqualine (458L) is a derivative of benzylisoquinoline, it inhibited kidney histidine decarboxylase and decreased the passive anaphylactic bronchospasm in guinea pigs. Altoqualine is an antihistamine and antiallergic agent.

Amfepentorex (CB 2201) was marketed as an appetite suppressant in France in the 1970s.

Alphamethadol is a synthetic opioid analgesic. Alphamethadol is composed of two isomers itself, L-α-methadol, and D-α-methadol. L-α-methadol is an important active metabolite of levacetylmethadol (LAAM), a medication therapy for individuals addicted to opiates that provides an alternative to methadone. Isomers of Alphamethadol bind to and activate the μ-opioid receptor; they are active as opioid analgesics.

Altapizone is a platelet aggregation inhibitor. It is a vasodilator.

Dimeprozan is a tranquillizer. It is equipotent with chlorpromazine in producing ataxia, decreased motor activity, and loss of righting reflex in mice.

Begacestat (GSI-953 or PF-5212362), a gamma-secretase inhibitor (GSI) that selectively inhibits cleavage of APP over Notch, was discovered for the treatment of Alzheimer's disease. The drug has shown promise results in phase I clinical trials, however further studies were discontinued.

Bolazine is a synthetic anabolic steroid that uses as the ester prodrug bolazine capronate.

Bofumustine, also known as RFCNU was studied as an antitumor agent. Bofumustine participated in phase II trials in patients with digestive tract tumors. It was shown that 30% has remissions among which 13% were greater than 50%. In addition, bofumustine participated in phase II clinical trials, where it showed to be effective in 8% of digestive tumors, in 1 out of 7 pancreatic cancers and in 3 out of 10 hepatic and pulmonary metastases from an undiscovered primary adenocarcinoma. However, further information is not available.