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Showing 51 - 60 of 418 results

Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Zidovudine 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. Zidovudine, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ. Zidovudine is used in combination with other antiretroviral agents for the treatment of human immunovirus (HIV) infections. Zidovudine is marketed as Retrovir.
Dexketoprofen is a nonsteroidal anti-inflammatory drug (NSAID), manufactured by Menarini under the tradename Keral. Dexketoprofen is indicated for short-term treatment of mild to moderate pain, including dysmenorrhoea. Dexketoprofen works by blocking the action of a substance in the body called cyclo-oxygenase, which is involved in the production of chemicals in the body called prostaglandins. Prostaglandins are produced in response to injury or certain diseases and would otherwise go on to cause swelling, inflammation, and pain. By blocking cyclo-oxygenase, dexketoprofen prevents the production of prostaglandins and therefore reduces inflammation and pain. Along with peripheral analgesic action, it possesses central analgesic action. Dexketoprofen may cause dizziness, and patients should not, therefore, drive or operate heavy machinery or vehicles until they are familiar with how dexketoprofen affects them. Concomitant use of alcohol and other sedatives may potentiate this effect. In a small subset of individuals, the dizziness may be intolerable and require the transition to an alternative treatment.
Flurbiprofen, a propionic acid derivative, is a nonsteroidal anti-inflammatory drug that exhibits antiinflammatory, analgesic, and antipyretic activities in animal models. Flurbiprofen Tablets are indicated for relief of the signs and symptoms of rheumatoid arthritis and for relief of the signs and symptoms of osteoarthritis. It may also be used to treat pain associated with dysmenorrhea and mild to moderate pain accompanied by inflammation (e.g. bursitis, tendonitis, soft tissue trauma). Flurbiprofen may also be used topically prior to ocular surgery to prevent or reduce intraoperative miosis. Similar to other NSAIAs, the anti-inflammatory effect of flurbiprofen occurs via reversible inhibition of cyclooxygenase (COX), the enzyme responsible for the conversion of arachidonic acid to prostaglandin G2 (PGG2) and PGG2 to prostaglandin H2 (PGH2) in the prostaglandin synthesis pathway. This effectively decreases the concentration of prostaglandins involved in inflammation, pain, swelling and fever. Flurbiprofen is a non-selective COX inhibitor and inhibits the activity of both COX-1 and -2. It is also one of the most potent NSAIAs in terms of prostaglandin inhibitory activity.
Ceftazidime is a semisynthetic, broad-spectrum, beta-lactam antibiotic, used especially for Pseudomonas and other gram-negative infections in debilitated patients. Ceftazidime is used to treat lower respiratory tract, skin, urinary tract, blood-stream, joint, and abdominal infections, and meningitis. The drug is given intravenously (IV) or intramuscularly (IM) every 8–12 hours (two or three times a day), with dose and frequency varying by the type of infection, severity, and/or renal function of the patient. Injectable formulations of ceftazidime are currently nebulized "off-label" to manage Cystic Fibrosis, non-Cystic Fibrosis bronchiectasis, drug-resistant nontuberculous mycobacterial infections, ventilator-associated pneumonia, and post-transplant airway infections. Ceftazidime is generally well-tolerated. When side effects do occur, they are most commonly local effects from the intravenous line site, allergic reactions, and gastrointestinal symptoms. According to one manufacturer, in clinical trials, allergic reactions including itching, rash, and fever, happened in fewer than 2% of patients. Rare but more serious allergic reactions, such as toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme, have been reported with this class of antibiotics, including ceftazidime. Gastrointestinal symptoms, including diarrhea, nausea, vomiting, and abdominal pain, were reported in fewer than 2% of patients.
Midazolam, previously marketed under the trade name Versed, is a medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation. Midazolam is a short-acting benzodiazepine central nervous system (CNS) depressant. Pharmacodynamic properties of midazolam and its metabolites, which are similar to those of other benzodiazepines, include sedative, anxiolytic, amnesic and hypnotic activities. Benzodiazepine pharmacologic effects appear to result from reversible interactions with the γ-amino butyric acid (GABA) benzodiazepine receptor in the CNS, the major inhibitory neurotransmitter in the central nervous system. The action of midazolam is readily reversed by the benzodiazepine receptor antagonist, flumazenil. Data from published reports of studies in pediatric patients clearly demonstrate that oral midazolam provides safe and effective sedation and anxiolysis prior to surgical procedures that require anesthesia as well as before other procedures that require sedation but may not require anesthesia. The most commonly reported effective doses range from 0.25 to 1 mg/kg in children (6 months to <16 years). The single most commonly reported effective dose is 0.5 mg/kg. Time to onset of effect is most frequently reported as 10 to 20 minutes. The effects of midazolam on the CNS are dependent on the dose administered, the route of administration, and the presence or absence of other medications.
Status:

Class (Stereo):
CHEMICAL (MIXED)


Conditions:

Labetalol is a blocker of both alpha- and beta-adrenergic receptors that is used as an antihypertensive. It may be used alone or in combination with other antihypertensive agents, especially thiazide and loop diuretics. The capacity of labetalol HCl to block alpha receptors in man has been demonstrated by attenuation of the pressor effect of phenylephrine and by a significant reduction of the pressor response caused by immersing the hand in ice-cold water ("cold-pressor test"). Labetalol HCl's beta1-receptor blockade in man was demonstrated by a small decrease in the resting heart rate, attenuation of tachycardia produced by isoproterenol or exercise, and by attenuation of the reflex tachycardia to the hypotension produced by amyl nitrite. Beta2-receptor blockade was demonstrated by inhibition of the isoproterenol-induced fall in diastolic blood pressure. Both the alpha- and beta-blocking actions of orally administered labetalol HCl contribute to a decrease in blood pressure in hypertensive patients. Labetalol HCl consistently, in dose-related fashion, blunted increases in exercise-induced blood pressure and heart rate, and in their double product. The pulmonary circulation during exercise was not affected by labetalol HCl dosing. Single oral doses of labetalol HCl administered to patients with coronary artery disease had no significant effect on sinus rate, intraventricular conduction, or QRS duration. The atrioventricular (A-V) conduction time was modestly prolonged in two of seven patients. In another study, IV labetalol HCl slightly prolonged A-V nodal conduction time and atrial effective refractory period with only small changes in heart rate. The metabolism of labetalol is mainly through conjugation to glucuronide metabolites. These metabolites are present in plasma and are excreted in the urine and, via the bile, into the feces. Approximately 55% to 60% of a dose appears in the urine as conjugates or unchanged labetalol within the first 24 hours of dosing. Labetalol has been shown to cross the placental barrier in humans. Only negligible amounts of the drug crossed the blood-brain barrier in animal studies. Labetalol is approximately 50% protein bound. Neither hemodialysis nor peritoneal dialysis removes a significant amount of labetalol HCl from the general circulation.
Cyclosporins are cyclic polypeptide macrolides that were originally derived from the soil fungus Tolypocladium inflatum. Cyclosporine (also known as cyclosporine A) was discovered by Sandoz and developed for the tretment of immune disorders. The drug was approved by FDA for such diseases as Rheumatoid Arthritis, Psoriasis (Neoral), Keratoconjunctivitis sicca (Restasis) and prevention of transplant rejections (Neoral and Sandimmune). Cyclosporine’s primary immunosuppressive mechanism of action is inhibition of T-lymphocyte function. Upon administration cyclosporine binds to cyclophilin A and thus inhibits calcineurin, leading to immune system suppression.
Status:
First approved in 1983

Class (Stereo):
CHEMICAL (ABSOLUTE)



Etoposide (trade name Etopophos) is a semisynthetic derivative of podophyllotoxin that exhibits antitumor activity. It has been in clinical use for more than two decades and remains one of the most highly prescribed anticancer drugs in the world. The primary cytotoxic target for etoposide is topoisomerase II. This ubiquitous enzyme regulates DNA under- and over winding, and removes knots and tangles from the genome by generating transient double-stranded breaks in the double helix. Etoposide kills cells by stabilizing a covalent enzyme-cleaved DNA complex (known as the cleavage complex) that is a transient intermediate in the catalytic cycle of topoisomerase II. The accumulation of cleavage complexes in treated cells leads to the generation of permanent DNA strand breaks, which trigger recombination/repair pathways, mutagenesis, and chromosomal translocations. If these breaks overwhelm the cell, they can initiate death pathways. Thus, etoposide converts topoisomerase II from an essential enzyme to a potent cellular toxin that fragments the genome. Although the topoisomerase II-DNA cleavage complex is an important target for cancer chemotherapy, there also is evidence that topoisomerase II-mediated DNA strand breaks induced by etoposide and other agents can trigger chromosomal translocations that lead to specific types of leukemia. Etopophos (etoposide phosphate) is indicated in the management of the following neoplasms: Refractory Testicular Tumors-and for Small Cell Lung Cancer. The in vitro cytotoxicity observed for etoposide phosphate is significantly less than that seen with etoposide, which is believed due to the necessity for conversion in vivo to the active moiety, etoposide, by dephosphorylation. The mechanism of action is believed to be the same as that of etoposide.
Gemfibrozil, a fibric acid antilipemic agent similar to clofibrate, is used to treat hyperlipoproteinemia and as a second-line therapy for type IIb hypercholesterolemia. It acts to reduce triglyceride levels, reduce VLDL levels, reduce LDL levels (moderately), and increase HDL levels (moderately). Gemfibrozil increases the activity of extrahepatic lipoprotein lipase (LL), thereby increasing lipoprotein triglyceride lipolysis. It does so by activating Peroxisome proliferator-activated receptor-alpha (PPARα) 'transcription factor ligand', a receptor that is involved in metabolism of carbohydrates and fats, as well as adipose tissue differentiation. This increase in the synthesis of lipoprotein lipase thereby increases the clearance of triglycerides. Chylomicrons are degraded, VLDLs are converted to LDLs, and LDLs are converted to HDL. This is accompanied by a slight increase in secretion of lipids into the bile and ultimately the intestine. Gemfibrozil also inhibits the synthesis and increases the clearance of apolipoprotein B, a carrier molecule for VLDL. Gemfibrozil is most commonly sold as the brand name, Lopid. Other brand names include Jezil and Gen-Fibro.

Class (Stereo):
CHEMICAL (ACHIRAL)



Alprazolam, a benzodiazepine, is used to treat panic disorder and anxiety disorder. Unlike chlordiazepoxide, clorazepate, and prazepam, alprazolam has a shorter half-life and metabolites with minimal activity. Alprazolam may have significant drug interactions involving the hepatic cytochrome P-450 3A4 isoenzyme. Clinically, all benzodiazepines cause a dose-related central nervous system depressant activity varying from mild impairment of task performance to hypnosis. Unlike other benzodiazepines, alprazolam may also have some antidepressant activity, although clinical evidence of this is lacking. CNS agents of the 1,4 benzodiazepine class presumably exert their effects by binding at stereo specific receptors at several sites within the central nervous system. Their exact mechanism of action is unknown. Benzodiazepines bind nonspecifically to benzodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.