Thioguanine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute nonlymphocytic leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. Thioguanine was first synthesized and entered into clinical trial more than 30 years ago. It is a 6-thiopurine analogue of the naturally occurring purine bases hypoxanthine and guanine. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Thioguanine is cross-resistant with mercaptopurine. Cytotoxicity is cell cycle phase-specific (S-phase). Thioguanine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to 6-thioguanilyic acid (TGMP), which reaches high intracellular concentrations at therapeutic doses. TGMP interferes with the synthesis of guanine nucleotides by its inhibition of purine biosynthesis by pseudofeedback inhibition of glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway of purine ribonucleotide synthesis. TGMP also inhibits the conversion of inosinic acid (IMP) to xanthylic acid (XMP) by competition for the enzyme IMP dehydrogenase. Thioguanine nucleotides are incorporated into both the DNA and the RNA by phosphodiester linkages, and some studies have shown that incorporation of such false bases contributes to the cytotoxicity of thioguanine. Its tumor inhibitory properties may be due to one or more of its effects on feedback inhibition of de novo purine synthesis; inhibition of purine nucleotide interconversions; or incorporation into the DNA and RNA. The overall result of its action is a sequential blockade of the utilization and synthesis of the purine nucleotides. Thioguanine is used for remission induction and remission consolidation treatment of acute nonlymphocytic leukemias. It is marketed under the trade name Lanvis and Tabloid among others.

Idoxuridine is an antiviral agent use in keratitis caused by herpes simplex virus. As a prescription drug it comes as a 0.1% ophthalmic solution/drops (Herplex and Dendrid). The first studies of the compound for treatment of human herpes simplex started in early 1960s. Being a structural analog of thymidine idoxuridine inhibits viral DNA replication by substituting thymidine. The effect of idoxuridine results in the inability of the virus to reproduce and/or infect tissues. Idoxuridine also blocks viral thymidine kinase as its substrate analog.

Polythiazide is a thiazide diuretic with actions and uses similar to those of hydrochlorothiazide. Polythiazide under brand name Rense is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. Renese is indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs in the more severe forms of hypertension. The mechanism of action results in an interference with the renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosage, all thiazides are approximately equal in their diuretic potency. The mechanism whereby thiazides function in the control of hypertension is unknown, but as a diuretic, polythiazide inhibits active chloride reabsorption at the early distal tubule via the thiazide-sensitive Na-Cl cotransporter (TSC), resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like polythiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of polythiazide may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle.

Chloroxylenol is used as a preservative in cooling fluids, cosmetics, topical medications, urinary antiseptics and metal working fluids. Products containing Chloroxylenol are used for cleaning and disinfecting wounds, abrasions and abscesses, for minor cuts and scratches, insect bites, burns, inflammation of the skin. It is also found in hair conditioners, toilet cleaners, deodorants, soaps and paste. New use cases continue to be identified. Chloroxylenol has been shown to be effective at reducing the number of pathogenic bacteria in clinical environments. Chloroxylenol has been reviewed and is permitted for use within the European Union (EU) in cosmetic products and is also permitted for use in a number of topical pharmaceutical products as licensed by the UK Medicines and Health Regulatory Agency. Chloroxylenol could cause mild skin irritation in some individuals, or cause an allergic reaction in others. Developed in Europe in the 1920s and used in the United States since the 1950s, Chloroxylenol is one of the most mature antimicrobial agents

Amphenidone is a sedative and hypnotic drug. Aminophenidone was launched as Dornwal in April 1960 through a retail division of Wallace & Tiernan called Maltbie Laboratories. Amphenidone was a mild to moderate and safe antianxiety and antitension substance and suited mainly for neurotic anxiety reaction. Amphenidone has also been shown to have antithyroid activity.

Methyclothiazide, a diuretic-antihypertensive agent, is a member of the benzothiadiazine (thiazide) class of drugs. Methyclothiazide has a per mg natriuretic activity approximately 100 times that of the prototype thiazide, chlorothiazide. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic/natriuretic effects. Like other benzothiadiazines, methyclothiazide also has antihypertensive properties, and may be used for this purpose either alone or to enhance the antihypertensive action of other drugs. Methyclothiazide appears to block the active reabsorption of chloride and possibly sodium in the ascending loop of Henle, altering electrolyte transfer in the proximal tubule. This results in excretion of sodium, chloride, and water and, hence, diuresis. As a diuretic, methyclothiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like methyclothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of methyclothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. Methyclothiazide is used in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Also used as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.

Benzthiazide (trade names Aquatag, Dihydrex, Diucen, Edemax, Exna, Foven and others) is a thiazide diuretic used in the treatment of high blood pressure and edema. It is no longer available in the United States. As a diuretic, benzthiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. The following is a list of possible side effects that may occur from all constituting ingredients of Exna Tablet: vomiting, diarrhoea, photosensitivity reactions, increased in uric acid concentrations, megaloblastic anaemia, thrombocytopenia. Exna tablet may interact with the following drugs and products: ACE inhibitors, angiotensin II receptor antagonists, potassium-sparing diuretics.

Fluprednisolone is glucocorticoid with the general properties of the corticosteroids. It is the drug of choice for all conditions in which routine systemic corticosteroid therapy is indicated (hypersensitivity dermatoses, contact dermatitis, pemphigus, pemphigoid, lupus erythematosus, neoplasia etc), except adrenal deficiency states.

Clemizole is a drug in clinical development for the treatment of hepatitis C virus (HCV) infection. Clemizole is a novel inhibitor of TRPC5 channels. Clemizole is an H1 antagonist. Clemizole, an antihistamine drug that was once widely used for treatment of allergic disease, was recently discovered to be a potent inhibitor (IC50, 24 nM) of the interaction between an HCV protein (NS4B) and HCV RNA. Although clemizole was widely used during the 1950s and 1960s, this was before contemporary regulatory requirements were established for new drug development, and there is very minimal information about its pharmacokinetics and metabolism.

Aminoglutethimide, marketing as Cytadren has been used in the treatment of advanced breast and prostate cancer. It was formerly used for its weak anticonvulsant properties. Cytadren is indicated for the suppression of adrenal function in selected patients with Cushing’s syndrome. Morning levels of plasma cortisol in patients with adrenal carcinoma and ectopic ACTH producing tumors were reduced on the average to about one half of the pretreatment levels, and in patients with adrenal hyperplasia to about two thirds of the pretreatment levels, during 1-3 months of therapy with Cytadren. Data available from the few patients with adrenal adenoma suggest similar reductions in plasma cortisol levels. Measurements of plasma cortisol showed reductions to at least 50% of baseline or to normal levels in one third or more of the patients studied, depending on diagnostic groups and time of measurement. Because Cytadren does not affect the underlying disease process, it is used primarily as an interim measure until more definitive therapy such as surgery can be undertaken or in cases where such therapy is not appropriate. Only small numbers of patients have been treated for longer than 3 months. A decreased effect or “escape phenomenon” seems to occur more frequently in patients with pituitary dependent Cushing’s syndrome, probably because of increasing ACTH levels in response to decreasing glucocorticoid levels. Cytadren blocks several other steps in steroid synthesis, including the C-11, C-18, and C-21 hydroxylations and the hydroxylations required for the aromatization of androgens to estrogens, mediated through the binding of Cytadren to cytochrome P-450 complexes. A decrease in adrenal secretion of cortisol is followed by an increased secretion of pituitary adrenocorticotropic hormone (ACTH), which will overcome the blockade of adrenocortical steroid synthesis by Cytadren. The compensatory increase in ACTH secretion can be suppressed by the simultaneous administration of hydrocortisone. Since Cytadren increases the rate of metabolism of dexamethasone but not that of hydrocortisone, the latter is preferred as the adrenal glucocorticoid replacement. Although Cytadren inhibits the synthesis of thyroxine by the thyroid gland, the compensatory increase in thyroid-stimulating hormone (TSH) is frequently of sufficient magnitude to overcome the inhibition of thyroid synthesis due to Cytadren. In spite of an increase in TSH, Cytadren has not been associated with increased prolactin secretion. At low doses, aminogluthethimide is only an effective inhibitor of aromatase (Cytochrome P450 11A1), but at higher doses, it effectively blocks Cytochrome P450 11A1 (P450scc) as well. Citadel was marketed previously as an anticonvulsant but was withdrawn from marketing for that indication in 1966 because of the effects on the adrenal gland.