Posizolid (AZD2563 or AZD5847) is an oxazolidinone, identified from an antibiotic research programme which aimed to synthesise agents that inhibited all Gram-positive bacteria, including multiresistant strains likely to be encountered clinically. Oxazolidinones bind to the 50S ribosomal subunit and inhibit the initiation phase of translation. Posizolid had been in phase II clinical trials for the treatment of tuberculosis. However, this study was discontinued.

Vanyldisulfamide is an anti-infective sulfonamide drug.

Azamulin [14-O-(5-(2-amino-1,3,4-triazolyl)thioacetyl)-dihydromutilin] is an azole derivative of the pleuromutilin class of antiinfectives. Azamulin is a selective, irreversible inhibitor of cytochrome P450 (CYP) 3A isoforms (IC50 values range from 26 to 240 nM for CYP3A4 and CYP3A4/5 from different sources). It is at least 50-fold less potent against CYP2J2 and 100-fold less effective against all other CYP isoforms. Azamulin potently blocks the hydroxylation of testosterone and midazolam by CYP3A4. Azamulin exhibited remarkable antibacterial activity against all Gram-positive pathogens including MRSA, PRSP, and VRE, except for E. faecalis.

FLOXACRINE, a dihydroacridinedione derivative, is an antimalarial agent. It showed high potency against blood-induced infection of drug-sensitive and drug-resistant lines of Plasmodium berghei in animal models.

Fomidacillin (also known as BRL 36650) is a type of penicillin with antibacterial activity. Studies on volunteers have shown that the drug possessed the bactericidal activity and could be a candidate for the treatment of gram-negative bacillary infections. However, information about the further development of this drug is not available.

Fosmidomycin (3-(formylhydroxyamino)-propylphosphonic acid mono-sodium salt, 3-(N-formyl-N-hydroxyamino)-propylphosphonic acid mono-sodium salt, FR-31564) is a potent inhibitor of P. falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR), developed by Albert Schweitzer Hospital for P. falciparum malaria treatment. Fosmidomycin was originally isolated as natural antibiotic from Streptomyces lavendulae. Fosmidomycin is active against a broad range of enterobacteria, but not against Gram-positive organisms or anaerobes. Fosmidomycin was developed as far as an early phase II study for the treatment of urinary tract infections by Fujisawa Pharmaceutical Company (Osaka, Japan) in the early eighties, but these trials have been discontinued. In recent clinical studies, it was shown that fosmidomycin is effective in curing uncomplicated Plasmodium falciparum malaria in humans. The treatment was well tolerated and resulted in a fast parasite and fever clearance. However, the high rate of recrudescence precludes the use of fosmidomycin as a monotherapy. In drug combination studies, the synergy of fosmidomycin with clindamycin was observed. Clinical studies with a fosmidomycin-clindamycin combination are currently ongoing.

Thiacetarsamide is a drug containing trivalent arsenic. In the USA it was used for the treatment of Heartworm Infection in dogs and cats under tradename Caparsolate, however, it was discontinued because of the availability of safer alternatives. The mechanism of action for thiacetarsamide is modulation of glucose uptake and metabolism; inhibition of glutathione reductase, and alteration of the structure and function of the surface of the intestinal epithelium of the parasites.

Mimbane was developed by Parke-Davis as an analgesic. Information about the current use of the drug is not available.

Lodenosine is the experimental HIV reverse transcriptase inhibitor. It was designed as a chemically and enzymatically stable anti-AIDS drug. A phase II trial of the nucleoside analog lodenosine was suspended after one participant died and others showed signs of liver or kidney damage.