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Pivampicillin
Pivampicillin is a pivaloyloxymethyl ester of ampicillin. It is a prodrug, which is thought to enhance the oral bioavailability of ampicillin because of its greater lipophilicity compared to that of ampicillin. Adverse effects Prodrugs that release pivalic acid when broken down by the body—such as pivampicillin, pivmecillinam, and cefditoren pivoxil—have long been known to deplete levels of carnitine. This effect is not due to the drug itself but to pivalate, which is mostly removed from the body by forming a conjugate with carnitine. Although short-term use of these drugs can cause a marked decrease in blood levels of carnitine, it is unlikely to be of clinical significance; long-term use, however, is not recommended. Availability Worldwide, pivampicillin is only available in Denmark, where it is sold as Pondocillin® by PharmaCoDane, or Miraxid® by LEO Pharma LEO Pharma A/S is a multinational Danish pharmaceutical company, founded in 1908, with a presence in about 100 co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivmecillinam
Pivmecillinam (INN) or amdinocillin pivoxil (USAN, trade names Selexid, Penomax and Coactabs) is an orally active prodrug of mecillinam, an extended-spectrum penicillin antibiotic. Pivmecillinam is the pivaloyloxymethyl ester of mecillinam. Pivmecillinam is only considered to be active against Gram-negative bacteria, and is used primarily in the treatment of lower urinary tract infections. In the Nordic countries, it has been widely used in that indication since the 1970s. It has been proposed as the first-line drug of choice for empirical treatment of acute cystitis. It has also been used to treat paratyphoid fever and shigellosis. Activity Adverse effects The adverse effect profile of pivmecillinam is similar to that of other penicillins. The most common side effects of mecillinam use are rash and gastrointestinal upset, including nausea and vomiting. Retrieved on August 31, 2008. Prodrugs that release pivalic acid when broken down by the body — such as pivmecillinam, pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivaloyloxymethyl
Pivaloyloxymethyl (POM, pivoxil, pivoxyl) is a protecting group used in organic synthesis.''Protective Groups in Organic Synthesis'', 3rd Edition, Theodora M. Greene and Peter G. M. Wuts, The POM radical has the formula (CH3)3C-CO-O-CH2. The POM group is also sometimes used to produce prodrugs. For example, the POM group can be attached to a negatively charged organophosphate group(s) of a drug causing a neutralization of the negative charge, which can allow the drug to become more lipid-soluble and thus more able to diffuse passively across cell membranes into cells. Upon entry into cells, the POM portion of the molecule can be removed by cellular processes resulting in release of active drug. Clinically used prodrugs containing pivaloyloxymethyl groups include adefovir dipivoxil, pivampicillin, cefditoren pivoxil, pivmecillinam, and valproate pivoxil. Tenofovir disoproxil contains a very similar prodrug group. See also * Pivalic acid Pivalic acid is a carboxylic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampicillin
Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include ''Clostridium difficile'' colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe. Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a generic medication. Medical uses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnitine
Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids into mitochondria to be oxidized for energy production, and also participates in removing products of metabolism from cells. Given its key metabolic roles, carnitine is concentrated in tissues like skeletal and cardiac muscle that metabolize fatty acids as an energy source. Generally individuals, including strict vegetarians, synthesize enough L-carnitine in vivo. Carnitine exists as one of two stereoisomers (the two enantiomers -carnitine (''S''-(+)-) and -carnitine (''R''-(−)-)). Both are biologically active, but only -carnitine naturally occurs in animals, and -carnitine is toxic as it inhibits the activity of the -form. At room temperature, pure carnitine is a whiteish powder, and a water-soluble zwitterion with relatively low toxicity. Derived from amino acids, carnitine was first extracte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. The kidney participates in the control of the volume of various body fluids, fluid osmolality, acid–base balance, various electrolyte concentrations, and removal of toxins. Filtration occurs in the glomerulus: one-fifth of the blood volume that enters the kidneys is filtered. Examples of substances reabsorbed are solute-free water, sodium, bicarbonate, glucose, and amino acids. Examples of substances secreted are hydrogen, ammonium, potassium and uric acid. The nephron is the structural and functional unit of the kidney. Each adult human kidney contains around 1 million nephrons, while a mouse kidney contains on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prodrug
A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug is absorbed, distributed, metabolized, and excreted (ADME). Prodrugs are often designed to improve bioavailability when a drug itself is poorly absorbed from the gastrointestinal tract. A prodrug may be used to improve how selectively the drug interacts with cells or processes that are not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. History Many herbal extracts historically used in medicine contain glycosides (sugar derivatives) of the active agent, which are hydrolyzed in the intestines to release the active and more bioavailable aglycone. For example, salicin is a β-D-glucopyranosid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via routes other than intravenous, its bioavailability is generally lower than that of intravenous due to intestinal endothelium absorption and first-pass metabolism. Thereby, mathematically, bioavailability equals the ratio of comparing the area under the plasma drug concentration curve versus time (AUC) for the extravascular formulation to the AUC for the intravascular formulation. AUC is used because AUC is proportional to the dose that has entered the systemic circulation. Bioavailability of a drug is an average value; to take population variability into account, deviation range is shown as ±. To ensure that the drug taker who has poor absorption is dosed appropriately, the bottom value o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipophilicity
Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipophilic (translated as "fat-loving" or "fat-liking"), and the axiom that "like dissolves like" generally holds true. Thus lipophilic substances tend to dissolve in other lipophilic substances, but hydrophilic ("water-loving") substances tend to dissolve in water and other hydrophilic substances. Lipophilicity, hydrophobicity, and non-polarity may describe the same tendency towards participation in the London dispersion force, as the terms are often used interchangeably. However, the terms "lipophilic" and "hydrophobic" are not synonymous, as can be seen with silicones and fluorocarbons, which are hydrophobic but not lipophilic. __TOC__ Surfactants Hydrocarbon-based surfactants are compounds that are amphiphilic (or amphipathic), having a hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pivalic Acid
Pivalic acid is a carboxylic acid with a molecular formula of (CH3)3CCO2H. This colourless, odiferous organic compound is solid at room temperature. A common abbreviation for the pivalyl or pivaloyl group (''t''-BuC(O)) is Piv and for pivalic acid (''t''-BuC(O)OH) is PivOH. Preparation Industrial route Pivalic acid is prepared by hydrocarboxylation of isobutene via the Koch reaction: :(CH3)2C=CH2 + CO + H2O → (CH3)3CCO2H Such reactions require an acid catalyst such as hydrogen fluoride. ''tert''-Butyl alcohol and isobutyl alcohol can also be used in place of isobutene. Globally, several million kilograms are produced annually. Pivalic acid is also economically recovered as a byproduct from the production of semisynthetic penicillins like ampicillin and amoxycillin. Laboratory methods It was originally prepared by the oxidation of pinacolone with chromic acid and by the hydrolysis of ''tert''-butyl cyanide. Convenient laboratory routes proceed via ''tert''-butyl chloride via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cefditoren Pivoxil
Cefditoren, also known as cefditoren pivoxil is an antibiotic used to treat infections caused by Gram-positive and Gram-negative bacteria that are resistant to other antibiotics. It is mainly used for treatment of community acquired pneumonia. It is taken by mouth and is in the cephalosporin family of antibiotics, which is part of the broader beta-lactam group of antibiotics. Structure Like other cephalosporins, cefditoren has a β-lactam ring at the 7 position of cephalosporin ring that is responsible for its inhibitory action on bacterial cell wall synthesis. In addition to the cephem nucleus common to all cephalosporins, cefditoren has an aminothiazole group that enhances its activity against Gram-negative organisms, a methylthiazole group that enhances its activity against Gram-positive organisms, a methoxyimino group that gives it stability against β-lactamases, and a pivoxil ester group that enhances oral bioavailability. Antimicrobial activity The spectrum of cefdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
