Mercaptopurine, marketed under the brand name Purinethol among others, is a medication used for cancer and autoimmune diseases. Mercaptopurine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to thioinosinic acid (TIMP). This intracellular nucleotide inhibits several reactions involving inosinic acid (IMP), including the conversion of IMP to xanthylic acid (XMP) and the conversion of IMP to adenylic acid (AMP) via adenylosuccinate (SAMP). In addition, 6-methylthioinosinate (MTIMP) is formed by the methylation of TIMP. Both TIMP and MTIMP have been reported to inhibit glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway for purine ribonucleotide synthesis. Experiments indicate that radiolabeled mercaptopurine may be recovered from the DNA in the form of deoxythioguanosine. Some mercaptopurine is converted to nucleotide derivatives of 6-thioguanine (6-TG) by the sequential actions of inosinate (IMP) dehydrogenase and xanthylate (XMP) aminase, converting TIMP to thioguanylic acid (TGMP). PURINETHOL (mercaptopurine) is indicated for maintenance therapy of acute lymphatic (lymphocytic, lymphoblastic) leukemia as part of a combination regimen. The response to this agent depends upon the particular subclassification of acute lymphatic leukemia and the age of the patient (pediatric or adult).

Furadantin (nitrofurantoin), a synthetic chemical, is a stable, yellow, crystalline compound. Furadantin is an antibacterial agent for specific urinary tract infections. Orally administered Furadantin is readily absorbed and rapidly excreted in urine. Blood concentrations at therapeutic dosage are usually low. Unlike many drugs, the presence of food or agents delaying gastric emptying can increase the bioavailability of Furadantin, presumably by allowing better dissolution in gastric juices. Nitrofurantoin is active against some gram positive organisms such as S. aureus, S. epidermidis, S. saprophyticus, Enterococcus faecalis, S. agalactiae, group D streptococci, viridians streptococci and Corynebacterium. Its spectrum of activity against gram negative organisms includes E. coli, Enterobacter, Neisseria, Salmonella and Shigella. It may be used as an alternative to trimethoprim/sulfamethoxazole for treating urinary tract infections though it may be less effective at eradicating vaginal bacteria. May also be used in females as prophylaxis against recurrent cystitis related to coitus. Nitrofurantoin is highly stable to the development of bacterial resistance, a property thought to be due to its multiplicity of mechanisms of action. Nitrofurantoin is activated by bacterial flavoproteins (nitrofuran reductase) to active reduced reactive intermediates that are thought to modulate and damage ribosomal proteins or other macromolecules, especially DNA, causing inhibition of DNA, RNA, protein, and cell wall synthesis. The overall effect is inhibition of bacterial growth or cell death.

Pyrimethamine, sold under the trade name Daraprim, is one of the folic acid antagonists that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis. In addition it was approved in Chemoprophylaxis of Malaria. However, resistance to pyrimethamine is prevalent worldwide. It is not suitable as a prophylactic agent for travelers to most areas. Pyrimethamine is well absorbed with peak levels occurring between 2 to 6 hours following administration. It is eliminated slowly and has a plasma half-life of approximately 96 hours. Pyrimethamine is 87% bound to human plasma proteins. Pyrimethamine acts by selectively inhibiting malarial dihydrofolate reductase-thymidylate synthase and the rationale for its therapeutic action is based on the differential requirement between host and parasite for nucleic acid precursors involved in growth. This activity is highly selective against plasmodia and Toxoplasma gondii. Pyrimethamine possesses blood schizonticidal and some tissue schizonticidal activity against malaria parasites of humans. The action of pyrimethamine against Toxoplasma gondii is greatly enhanced when used in conjunction with sulfonamides.

Methimazole (also known as Tapazole or Thiamazole or MMI) is an antithyroid drug. Methimazole binds to thyroid peroxidase and thereby inhibits the conversion of iodide to iodine. Thyroid peroxidase normally converts iodide to iodine (via hydrogen peroxide as a cofactor) and also catalyzes the incorporation of the resulting iodide molecule onto both the 3 and/or 5 positions of the phenol rings of tyrosines found in thyroglobulin. Thyroglobulin is degraded to produce thyroxine (T4) and tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. So methimazole effectively inhibits the production of new thyroid hormones. Methimazole is used for the treatment of hyperthyroidism, goiter, Graves disease and psoriasis.

Propylthiouracil is thyroid peroxidase inhibitor used to treat hyperthyroidism, which includes hyperthyroidism due to Graves' disease and toxic multinodular goiter. Propylthiouracil is used to ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy in patients who are intolerant of methimazole.

Phenytoin is an anti-epileptic drug. Phenytoin has been used with much clinical success against all types of epileptiform seizures, except petit mal epilepsy. Phenytoin is a available for oral administration (tablets, capsules, suspension). CEREBYX® (fosphenytoin sodium injection) is a prodrug intended for parenteral administration; its active metabolite is phenytoin. CEREBYX should be used only when oral phenytoin administration is not possible. Although several potential targets for phenytoin action have been identified within the CNS (Na-K-ATPase, the GABAA receptor complex, ionotropic glutamate receptors, calcium channels and sigma binding sites) to date, though, the best evidence hinges on the inhibition of voltage-sensitive Na channels in the plasma membrane of neurons undergoing seizure activity.

Piperonyl butoxide (PBO) is an organic compound used as a component of pesticide formulations. It is a waxy white solid. It is a semisynthetic derivative of safrole. It is used for the treatment of head, pubic (crab), and body lice. Piperonyl butoxide is a synergist. It has no pesticidal activity of its own, but acts to increase the activity of pesticides such as carbamates, pyrethrins, pyrethroids, and rotenone. PBO acts as an insecticide synergist by inhibiting the natural defense mechanisms of the insect, the most important of which is the Mixed Function Oxidase system, also known as the cytochrome P-450 system. The MFO system is the primary route of detoxification in insects, and causes the oxidative breakdown of insecticides like pyrethrins and the synthetic pyrethroids - thus when PBO is added, higher insecticide levels remain in the insect to exercise their lethal effect. An important consequence of this property is that, by enhancing the activity of a given insecticide, less may be used to achieve the same result. PBO does not appear to have a significant effect on the MFO system in humans. Skin Sensitization PBO has a low acute toxicity by oral, inhalation and dermal routes. It is minimally irritating to the eyes and skin. It is a not a dermal sensitizer. No evidence suggests that PBO disrupts the normal functioning of the endocrine system. This includes the recently developed data to assess the possible interaction of PBO with the endocrine system.

Caffeine is a methylxanthine alkaloid found in the seeds, nuts, or leaves of a number of plants native to South America and East Asia that is structurally related to adenosine and acts primarily as an adenosine receptor antagonist with psychotropic and anti-inflammatory activities. Upon ingestion, caffeine binds to adenosine receptors in the central nervous system (CNS), which inhibits adenosine binding. This inhibits the adenosine-mediated downregulation of CNS activity; thus, stimulating the activity of the medullary, vagal, vasomotor, and respiratory centers in the brain. The anti-inflammatory effects of caffeine are due the nonselective competitive inhibition of phosphodiesterases. Caffeine is used by mouth or rectally in combination with painkillers (such as aspirin and acetaminophen) and a chemical called ergotamine for treating migraineheadaches. It is also used with painkillers for simple headaches and preventing and treating headaches after epidural anesthesia. Caffeine creams are applied to the skin to reduce redness and itching in dermatitis. Healthcare providers sometimes give caffeine intravenously (by IV) for headache after epidural anesthesia, breathing problems in newborns, and to increase urine flow. In foods, caffeine is used as an ingredient in soft drinks, energy drinks, and other beverages.

Isopropanolamine (1-Amino-2-propanol) is a colorless to yellowish liquid with an amine-like odor. It is miscible in water. Intermediate used in the production of dyes, lubrification oils, corrosion inhibitor, detergents, cutting fluids.