Guanabenz, an antihypertensive agent for oral administration-, is an aminoguanidine derivative, 2,'6-dichlorobenzylideneamina-guanidine acetate. It is white to an almost white powder having not more than a slight odor. Sparingly soluble in water and in 0.1 N hydrochloric acid; soluble in alcohol and in propylene glycol. Guanabenz is an orally active central alpha-2 adrenergic agonist. Its antihypertensive action appears to be mediated via stimulation of central alpha-adrenergic receptors, resulting in a decrease of sympathetic outflow from the brain at the bulbar level to the peripheral circulatory system. In clinical trials, guanabenz acetate, given orally to hypertensive patients, effectively controlled blood pressure without any significant effect on glomerular filtration rate, renal blood flow, body fluid volume or body weight. The Myelin Repair Foundation and the National Institutes of Health (National Institute of Neurological Disorders and Stroke) are developing guanabenz for the treatment of multiple sclerosis. Unlike the currently available treatment for multiple sclerosis that suppresses the immune system, guanabenz, an FDA approved the drug for the treatment of high blood pressure, has a potential to reduce the loss of myelin by protecting and repairing myelin-producing cells in the brain from damage. Phase I development is underway in the US.

Cefoperazone (marketed under the name Cefobid) is a third-generation cephalosporin antibiotic. Cefoperazone has a broad spectrum of activity: Respiratory Tract Infections caused by S. pneumoniae, H. influenzae, S. aureus (penicillinase and non-penicillinase producing strains), S. pyogenes (Group A beta-hemolytic streptococci), P. aeruginosa, Klebsiella pneumoniae, E. coli, Proteus mirabilis, and Enterobacter species. Peritonitis and Other Intra-abdominal Infections caused by E. coli, P. aeruginosa, and anaerobic gram-negative bacilli (including Bacteroides fragilis). Bacterial Septicemia caused by S. pneumoniae, S. agalactiae, S. aureus, Pseudomonas aeruginosa, E. coli, Klebsiella spp., Klebsiella pneumoniae, Proteus species (indole-positive and indole-negative), Clostridium spp. and anaerobic gram-positive cocci. Infections of the Skin and Skin Structures caused by S. aureus (penicillinase and non-penicillinase producing strains), S. pyogenes, and P. aeruginosa. Pelvic Inflammatory Disease, Endometritis, and Other Infections of the Female Genital Tract caused by N. gonorrhoeae, S. epidermidis, S. agalactiae, E. coli, Clostridium spp., Bacteroides species (including Bacteroides fragilis), and anaerobic gram-positive cocci. Cefobid has no activity against Chlamydia trachomatis. Therefore, when Cefobid is used in the treatment of patients with pelvic inflammatory disease and C. trachomatis is one of the suspected pathogens, appropriate anti-chlamydial coverage should be added. Urinary Tract Infections caused by Escherichia coli and Pseudomonas aeruginosa. Cefoperazone, a third-generation cephalosporin, interferes with cell wall synthesis by binding to the penicillin-binding proteins (PBPs), thus preventing cross-linking of nascent peptidoglycan. Cefoperazone is stable to penicillinases and has a high degree of stability to many beta-lactamases produced by gram-negative bacteria. When tested in vitro, cefoperazone has demonstrated synergistic interactions with aminoglycosides against gram-negative bacilli. As with all cephalosporins, hypersensitivity manifested by skin reactions or drug fever. Reversible neutropenia may occur with prolonged administration. Diarrhea or loose stools has been reported also.

XENON XE-127, a radioactive gas, was developed at Brookhaven National Laboratory in 1973 for lung ventilation imaging. It appears to be preferable to xenon-133 because of the higher counting rates, lower patient radiation dose, and longer shelf life. However, its production ceased in 1993 due to various reasons.

Cefotaxime sodium is a semisynthetic, broad spectrum cephalosporin antibiotic for parenteral administration. It’s a 3rd Generation Cephalosporin that is FDA approved for the treatment of lower respiratory tract infections, genitourinary infections, gynecologic infections, bacteremia/septicemia, skin and skin structure infections, intra-abdominal infections, bone and/or joint infections and central nervous system infections. The bactericidal activity of cefotaxime sodium results from inhibition of cell wall synthesis. Cefotaxime sodium has in vitro activity against a wide range of gram-positive and gram-negative organisms. Cefotaxime sodium has a high degree of stability in the presence of ß-lactamases, both penicillinases and cephalosporinases, of gram-negative and gram-positive bacteria. Increased nephrotoxicity has been reported following concomitant administration of cephalosporins and aminoglycoside antibiotics. Common adverse reactions include injection site pain, injection site phlebitis, rash, diarrhea, vomiting. Increased nephrotoxicity has been reported following concomitant administration of cephalosporins and aminoglycoside antibiotics.

Sulfadoxine is an antimalarial agent which, together with pyrimethamine, composes an FDA-approved drug, Fansidar. Sulfadoxine acts by inhibiting dihydropteroate synthase; it crosses the blood-brain barrier and achieves 30% to 60% of the plasma concentration.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.

Dipivefrin is a prodrug with little or no pharmacologically activity until it is hydrolyzed into epinephrine inside the human eye. The liberated epinephrine, an adrenergic agonist, appears to exert its action by stimulating α -and/or β2-adrenergic receptors, leading to a decrease in aqueous production and an enhancement of outflow facility. The dipivefrin prodrug delivery system is a more efficient way of delivering the therapeutic effects of epinephrine, with fewer side effects than are associated with conventional epinephrine therapy. Dipivefrin is used as initial therapy for the control of intraocular pressure in chronic open-angle glaucoma.

Oxamniquine is an anthelmintic with schistosomicidal activity against Schistosoma mansoni, but not against other Schistosoma spp. Oxamniquine is a potent single-dose agent for treatment of S. mansoni infection in man, and it causes worms to shift from the mesenteric veins to the liver, where the male worms are retained; the female worms return to the mesentery, but can no longer release eggs. Oxamniquine is a semisynthetic tetrahydroquinoline and possibly acts by DNA binding, resulting in contraction and paralysis of the worms and eventual detachment from terminal venules in the mesentry, and death. Its biochemical mechanisms are hypothesized to be related to an anticholinergic effect, which increases the parasite’s motility, as well as to synthesis inhibition of nucleic acids. Oxamniquine acts mainly on male worms, but also induces small changes on a small proportion of females. Like praziquantel, it promotes more severe damage of the dorsal tegument than of the ventral surface. The drug causes the male worms to shift from the mesenteric circulation to the liver, where the cellular host response causes its final elimination. The changes caused in the females are reversible and are due primarily to the discontinued male stimulation rather than the direct effect of oxamniquine

Etidronate is a salt of etidronic acid (brand name Didronel, also known as EHDP) a diphosphonate, which is indicated for the treatment of symptomatic Paget’s disease of bone and in the prevention and treatment of heterotopic ossification following total hip replacement or due to spinal cord injury. Didronel is not approved for the treatment of osteoporosis. This drugs acts primarily on bone. It can inhibit the formation, growth, and dissolution of hydroxyapatite crystals and their amorphous precursors by chemisorption to calcium phosphate surfaces. Inhibition of crystal resorption occurs at lower doses than are required to inhibit crystal growth. Both effects increase as the dose increases. Preclinical studies indicate etidronate disodium does not cross the blood-brain barrier. Didronel is not metabolized. The amount of drug absorbed after an oral dose is approximately 3 percent. Bisphosphonates, when attached to bone tissue, are absorbed by osteoclasts, the bone cells that breaks down bone tissue. Although the mechanism of action of non-nitrogenous bisphosphonates has not been fully elucidated, available data suggest that they bind strongly to hydroxyapatite crystals in the bone matrix, preferentially at the sites of increased bone turnover and inhibit the formation and dissolution of the crystals. Other actions may include direct inhibition of mature osteoclast function, promotion of osteoclast apoptosis, and interference with osteoblast-mediated osteoclast activation. Etidronic acid may promote osteoclast apoptosis by competing with adenosine triphosphate (ATP) in the cellular energy metabolism. The osteoclast initiates apoptosis and dies, leading to an overall decrease in the breakdown of bone.

Ticarcillin (also known as Ticar) is a semisynthetic antibiotic with a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria. Ticarcillin is not absorbed orally; therefore, it must be given intravenously or intramuscularly. Ticarcillin's antibiotic properties arise from its ability to prevent cross-linking of peptidoglycan during cell wall synthesis when the bacteria tries to divide, causing death. Usage of ticar was discontinued.