Stavudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Stavudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. Stavudine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate dGTP and by its incorporation into viral DNA. Stavudine is used for the treatment of human immunovirus (HIV) infections. Stavudine is sold under the brand name Zerit among others.

Clofibrate is a fibric acid derivative used to lower cholesterol and triglyceride (fat-like substances) levels in the blood. This may help prevent medical problems caused by such substances clogging the blood vessels. However, this treatment was discontinued in 2002 due to adverse effects. Clofibrate is an agonist of the PPAR-α receptor in muscle, liver, and other tissues. This agonism ultimately leads to modification in gene expression resulting in increased beta-oxidation, decreased triglyceride secretion, increased HDL, and increased lipoprotein lipase activity. Clofibrate increased the activity of extrahepatic lipoprotein lipase (LL), thereby increasing lipoprotein triglyceride lipolysis, inhibited the synthesis, and increases the clearance of apolipoprotein B, a carrier molecule for VLDL. In addition, clofibrate was investigated as a novel therapy agent in multiple myeloma and it shown the promising results.

Chlorprothixene (Taractan, Tarasan, Truxal) is a thioxanthine derivative developed by Lundbeck for the treatment of psychotic disorders. The drug exerts its activity by binding to and inhibiting serotonin receptors, dopamine receptors, muscarinic acetylcholine receptor, histamine H1 receptor and alpha1-adrenergic receptor.

Sulfinpyrazone was approved by the U.S. Food and Drug Administration (FDA) on May 13, 1959. It was developed and marketed as Anturane® by Novartis. Sulfinpyrazone is an oral uricosuric agent (pyrazolone derivative) used to treat chronic or intermittent gouty arthritis. Sulfinpyrazone competitively inhibits the reabsorption of uric acid at the proximal convoluted tubule, thereby facilitating urinary excretion of uric acid and decreasing plasma urate concentrations. This is likely done through inhibition of the urate anion transporter (hURAT1) as well as the human organic anion transporter 4 (hOAT4). Sulfinpyrazone is not intended for the treatment of acute attacks because it lacks therapeutically useful analgesic and anti-inflammatory effects. Sulfinpyrazone and its sulfide metabolite possess COX inhibitory effects. Sulfinpyrazone has also been shown to be a UDP-glucuronsyltransferase inhibitor and a very potent CYP2C9 inhibitor. Sulfinpyrazone is also known to be a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor as well as an inhibitor of several multridrug resistance proteins (MRPs). Branded and generic forms of sulfinpyrazone have been discontinued in the US.

Chlorpropamide (DIABINESE®), is a sulfonylurea hypoglycemic agent used in the treatment of non-insulin-dependent diabetes mellitus not responding to dietary modification. It appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which chlorpropamide (DIABINESE®) lowers blood glucose during long-term administration has not been clearly established. Extra-pancreatic effects may play a part in the mechanism of action of oral sulfonylurea hypoglycemic drugs. While chlorpropamide is a sulfonamide derivative, it is devoid of antibacterial activity. Chlorpropamide (DIABINESE®) may also prove effective in controlling certain patients who have experienced primary or secondary failure to other sulfonylurea agent.

Acenocoumarol is mono-coumarin derivative with racemic mixture of R (+) and S (-) enantiomers. Acenocoumarol is structurally similar to vitamin K and is competitively able to inhibit the enzyme vitamin K-epoxide reductase. It exerts anticoagulant action by preventing the regeneration of reduced vitamin K by interfering with action of vitamin K epoxide reductase. Acenocoumarol is prescribed as the anticoagulant in various thromboembolic disorders.

Reserpine is an alkaloid, isolated from the Rauwolfia serpentina plant and developed by Ciba pharma. Reserpine was approved by FDA for the treatment of hypertension and psychotic disorders. The drug exerts its effect by blocking two vesicular monoamine transporters, VMAT1 and VMAT2. The blockade results in vesicles that lose their ability to store neurotransmitter molecules. Neurotransmitters, thus retained in cytosol, are then neutralized by MAO.

Phenylbutazone is an anti-inflammatory drug, which binds to and inactivates cyclooxygenases and prostacyclin synthase through peroxide (H2O2) mediated deactivation. The reduced production of prostaglandin leads to reduced inflammation of the surrounding tissues. Phenylbutazone was marked under the brand name butazolidin for the treatment rheumatoid arthritis and gout, but then this usage was discontinued. In addition, phenylbutazone is used in UK for the treatment of ankylosing spondylitis, but only in those cases, when other therapies are unsuitable.

Phenindione is an anticoagulant which functions as a Vitamin K antagonist. The drug was discontinued in USA, but still in use worldwide.

Tubocurarine, a naturally occurring alkaloid, is used to treat smoking withdrawl syndrom. Tubocurarine, the chief alkaloid in tobacco products, binds stereo-selectively to nicotinic-cholinergic receptors at the autonomic ganglia, in the adrenal medulla, at neuromuscular junctions, and in the brain. Two types of central nervous system effects are believed to be the basis of Tubocurarine's positively reinforcing properties. A stimulating effect is exerted mainly in the cortex via the locus ceruleus and a reward effect is exerted in the limbic system. At low doses the stimulant effects predominate while at high doses the reward effects predominate. Intermittent intravenous administration of Tubocurarine activates neurohormonal pathways, releasing acetylcholine, norepinephrine, dopamine, serotonin, vasopressin, beta-endorphin, growth hormone, and ACTH. Tubocurarine competes with acetylcholine for post-synaptic nicotinic NM receptors and blocks them.