Instruct: Given a question, retrieve passages that answer the question.
Query: Is metabolite a drug?
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body. Usually these effects are similar to those of the parent drug but weaker, although they can still be significant (see e.g. 11-hydroxy-THC, morphine-6-glucuronide). Certain drugs such as codeine and tramadol have metabolites (morphine and "O"-desmethyltramadol respectively) that are stronger than the parent drug and in these cases the metabolite may be responsible for much of the therapeutic action of the parent drug. Sometimes, however, metabolites may produce toxic effects and patients must be monitored carefully to ensure they do not build up in the body. This is an issue with some well-known drugs such as pethidine (meperidine) and dextropropoxyphene.
There are two major medications derived from methylphenidate's isomers: a racemic mixture of half d-threo-methylphenidate and half l-threo-methylphenidate called methylphenidate (Ritalin, Concerta), and an enantiopure formulation containing just d-threo-methylphenidate called dexmethylphenidate (Focalin).
JWH-018 usage is readily detected in urine using "spice" screening immunoassays from several manufacturers focused on both the parent drug and its omega-hydroxy and carboxyl metabolites. JWH-018 will not be detected by older methods employed for detecting THC and other cannabis terpenoids. Determination of the parent drug in serum or its metabolites in urine has been accomplished by GC-MS or LC-MS. Serum JWH-018 concentrations are generally in the 1–10 μg/L range during the first few hours after recreational usage. The major urinary metabolite is a compound that is monohydroxylated on the omega minus one carbon atom of the alkyl side chain. A lesser metabolite monohydroxylated on the omega (terminal) position was present in the urine of 6 users of the drug at concentrations of 6–50 μg/L, primarily as a glucuronide conjugate.
Corticosteroids (cortisone), accutane (isotretinoin) and other vitamin A derivatives, barbiturates, certain antibiotics, propofol, volatile anesthetics, non-depolarizing muscle relaxants, some local anesthetics, statins, fibrates, glitazones, beta blockers, biguanides, amiodarone, some chemotherapies, some neuroleptics, nucleoside reverse transcriptase inhibitors and various other drugs.
Sometimes drugs are formulated in an inactive form that is designed to break down inside the body to form the active drug. These are called prodrugs. The reasons for this type of formulation may be because the drug is more stable during manufacture and storage as the prodrug form, or because the prodrug is better absorbed by the body or has superior pharmacokinetics (e.g., lisdexamphetamine).
Bioequivalence does not mean generic drugs must be exactly the same as the brand-name product ("pharmaceutical equivalent"). Chemical differences may exist; a different salt or ester may be used, for instance. Different inactive ingredients means that the generic may look different to the originator brand. However, the therapeutic effect of the drug must be the same ("pharmaceutical alternative"). Most small molecule drugs are accepted as bioequivalent if their pharmacokinetic parameters of area under the curve (AUC) and maximum concentration (C) are within a 90% confidence interval of 80–125%; most approved generics are well within this limit. For more complex products—such as inhalers, patch delivery systems, liposomal preparations, or biosimilar drugs—demonstrating pharmacodynamic or clinical equivalence is more challenging.
A generic drug is a chemically equivalent, cheaper version of a brand-name drug. A generic drug form is required to have the same dose, strength and active ingredient(s) as the brand name drug; thus, they carry the same risks and benefits. To ensure compliance, the FDA Generic Drugs Program conducts stringent reviews (3,500 inspections of manufacturing plants per year). Although generic drugs sound like a great money-saver, generic medicines can only be sold after the patents of the brand name versions end. Because of this mandatory period of exclusivity for many brand-name drugs (a period in which generic medicines cannot be sold), delay of generic drugs reaching the market is expected. The high cost of upfront research that the brand-name products have to go through to ensure safety and efficacy largely account for the high discrepancy in pricing between the two groups.
Group D
Group C
An organic diet is an effective way to reduce exposure to the organophosphorus pesticides commonly used in agricultural production. Organophosphate metabolite levels rapidly drop, and for some metabolites, become undetectable in children's urine when an organic diet is consumed. This is speculative based on a short study of 23 children, in which only a few organophosphate compounds were potentially reduced, no effect was shown for the majority of them that were found in the samples.
Dexmethylphenidate has a 4–6 hour duration of effect (a long-acting formulation, Focalin XR, which spans 12 hours is also available and has been shown to be as effective as -TMP (threo-methylphenidate) XR (extended release) (Concerta, Ritalin LA), with flexible dosing and good tolerability.) It has also been demonstrated to reduce ADHD symptoms in both children and adults. d-MPH has a similar side-effect profile to MPH and can be administered without regard to food intake.
Zopiclone, as traditionally sold worldwide, is a racemic mixture of two stereoisomers, only one of which is active. In 2005, the pharmaceutical company Sepracor of Marlborough, Massachusetts began marketing the active stereoisomer eszopiclone under the name Lunesta in the United States. This had the consequence of placing what is a generic drug in most of the world under patent control in the United States. Generic forms of Lunesta have since become available in the United States. Zopiclone is currently available off-patent in a number of European countries, as well as Brazil, Canada, and Hong Kong. The eszopiclone/zopiclone difference is in the dosage—the strongest eszopiclone derivative dosage contains 3 mg of the therapeutic stereoisomer, whereas the highest zopiclone dosage (10 mg) contains 5 mg of the active stereoisomer. The two agents have not yet been studied in head-to-head clinical trials to determine the existence of any potential clinical differences (efficacy, side effects, developing dependence on the drug, safety, etc.).
H-antihistamines are among first-line therapy to treat gastrointestinal conditions including peptic ulcers and gastroesophageal reflux disease. Some formulations are available over the counter. Most side effects are due to cross-reactivity with unintended receptors. Cimetidine, for example, is notorious for antagonizing androgenic testosterone and DHT receptors at high doses.
Estradiol, estrone, and estriol have all been approved as pharmaceutical drugs and are used medically. Estetrol is currently under development for medical indications, but has not yet been approved in any country. A variety of synthetic estrogen esters, such as estradiol valerate, estradiol cypionate, estradiol acetate, estradiol benzoate, estradiol undecylate, and polyestradiol phosphate, are used clinically. The aforementioned compounds behave as prodrugs to estradiol, and are much longer-lasting in comparison when administered by intramuscular or subcutaneous injection. Esters of estrone and estriol also exist and are or have been used in clinical medicine, for example estrone sulfate (e.g., as estropipate), estriol succinate, and estriol glucuronide (as Emmenin and Progynon).
A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations for the chemical elements, and subscripts to indicate the number of atoms involved. For example, water is composed of two hydrogen atoms bonded to one oxygen atom: the chemical formula is HO. Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service (CAS): its CAS number.
Any substance consisting of two or more different types of atoms (chemical elements) in a fixed stoichiometric proportion can be termed a "chemical compound"; the concept is most readily understood when considering pure chemical substances. It follows from their being composed of fixed proportions of two or more types of atoms that chemical compounds can be converted, via chemical reaction, into compounds or substances each having fewer atoms. The ratio of each element in the compound is expressed in a ratio in its chemical formula. A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations for the chemical elements, and subscripts to indicate the number of atoms involved. For example, water is composed of two hydrogen atoms bonded to one oxygen atom: the chemical formula is HO. In the case of non-stoichiometric compounds, the proportions may be reproducible with regard to their preparation, and give fixed proportions of their component elements, but proportions that are not integral [e.g., for palladium hydride, PdH (0.02 < x < 0.58)].
Bis-choline tetrathiomolybdate (or tiomolibdate USAN, trade name Decuprate), is a salt of tetrathiomolybdate (TTM, MoS) and choline currently under investigation as a therapy against Wilson's disease, a rare and potentially fatal disease in which the body cannot regulate copper. Wilson's disease is an autosomal recessive genetic disorder that is manifested by serious hepatic, neurologic or psychiatric symptoms. The disease is fatal if left undiagnosed and untreated. It is estimated that approximately 1 individual in every 30,000 worldwide have Wilson's disease, corresponding to approximately 15,000 individuals in the European Union and approximately 11,000 in the United States.
Currently most people who use an antihistamine to treat allergies use a second generation drug.
21st century begins with the first complete sequences of individual human genomes by Human Genome Project, on February 12, 2001, this allowed a switch in drug development and research from the traditional way of drug discovery that was isolating molecules from plants or animals or create new molecules and see if they could be useful in treatment of illness in humans, to pharmacogenomics, that is the study and knowledge of how genes respond to drugs. Another field beneficed by Human Genome Project is pharmacogenetics, that is the study of inherited genetic differences in drug metabolic pathways which can affect individual responses to drugs, both in terms of therapeutic effect as well as adverse effects.
Wilson Therapeutics' lead product, Decuprate, is the proprietary bis-choline salt of tetrathiomolybdate. Decuprate is initially being developed as a novel treatment for Wilson's disease, a rare genetic disease that affects approximately 1 in 30,000, causing copper overload in the liver, brain and other tissues and resulting in organ damage and dysfunction. Decuprate has been granted orphan drug designation for the treatment of Wilson's disease in both Europe and the United States.. Wilson Therapeutics presented during the 10th Kempen & Co Life Sciences Conference 2017 and showed the world the result with the drug Decuprate. The company also presented during the international investmentconference Bioequity Europe in Paris, France, on May 23rd 2017 and showed some promising result.
Chemical compounds have a unique and defined chemical structure held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be molecular compounds held together by covalent bonds, salts held together by ionic bonds, intermetallic compounds held together by metallic bonds, or the subset of chemical complexes that are held together by coordinate covalent bonds. Pure chemical elements are generally not considered chemical compounds, failing the two or more atom requirement, though they often consist of molecules composed of multiple atoms (such as in the diatomic molecule H, or the polyatomic molecule S, etc.). Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service (CAS): its CAS number.
Metabolites from chemical compounds, whether inherent or pharmaceutical, are formed as part of the natural biochemical process of degrading and eliminating the compounds. The rate of degradation of a compound is an important determinant of the duration and intensity of its action. Profiling metabolites of pharmaceutical compounds, drug metabolism, is an important part of drug discovery, leading to an understanding of any undesirable side effects.
A drug or its metabolite may also stimulate CD8 T or CD4 T cells to initiate autoimmune responses by directly binding to the T cell receptors on these T cells. Again, this binding appears to develop only on certain T cell receptors. Since the genes for these receptors are highly edited, i.e. altered to encode proteins with different amino acid sequences, and since the human population may express more than 100 trillion different (i.e. different amino acid sequences) T cell receptors while an individual express only a fraction of these, a drug's or its metabolite's ability to induce the DRESS syndrome by interacting with a T cell receptor is limited to those individuals whose T cells express a T cell receptor(s) that can interact with drug or its metabolite. Thus, only rare individuals are predisposed to develop a SCARs disorder in response to a particular drug on the bases of their expression of specific cell receptor types. While the evidence supporting these ideas is limited, one study identified the preferential presence of the TCR-V-b and complementarity determining region 3 in T cell receptors found on the T cells in the blisters of patients with allopurinol-induced DRESS syndrome. This finding is compatible with the notion that specific types of T cell receptors are involved in the development of specific drug-induced SCARs.
Flumequine is considered to be well absorbed and is excreted in the urine and feces as the glucuronide conjugates of the parent drug and 7-hydroxyflumequine. It is eliminated within 168 hours post-dosing. However, studies concerning the calf liver showed additional unidentified residues, of which a new metabolite, ml, represented the major single metabolite 24 hours after the last dose and at all subsequent time points. The metabolite ml, which exhibited no antimicrobial activity, was present in both free and protein-bound fractions. The major residue found in the edible tissues of sheep, pigs, and chickens was parent drug together with minor amounts of the 7-hydroxy-metabolite. The only detected residue in trout was the parent drug.
Like other SCARs-inducing drugs, DRESS syndrome-inducing drugs or their metabolites stimulate CD8 T or CD4 T cells to initiate autoimmune responses. Studies indicate that the mechanism by which a drug or its metabolites accomplishes this stimulation involves subverting the antigen presentation pathways of the innate immune system. The drug or metabolite covalently binds with a host protein to form a non-self, drug-related epitope. An antigen presenting cell (APC) takes up these alter proteins; digests them into small peptides; places the peptides in a groove on the human leukocyte antigen (i.e. HLA) component of their major histocompatibility complex (i.e. MHC); and presents the MHC-associated peptides to the T-cell receptor on CD8 T or CD4 T cells. Those peptides expressing a drug-related, non-self epitope on their HLA-A, HLA-B, HLA-C, HLA-DM, HLA-DO, HLA-DP, HLA-DQ, or HLA-DR proteins may bind to a T-cell receptor to stimulate the receptor-bearing parent T cell to initiate attacks on self tissues. Alternatively, a drug or metabolite may stimulate these T cells by inserting into the groove on a HLA protein to serve as a non-self epitope or bind outside of this groove to alter a HLA protein so that it forms a non-self epitope. Importantly, however, non-self epitopes must bind to specific HLA serotypes in order to stimulate T cells. Since the human population expresses some 13,000 different HLA serotypes while an individual expresses only a fraction of them and since a DRESSs-inducing drug or metabolite interacts with only one or a few HLA serotypes, a drug's ability to induce SCARs is limited to those individuals who express HLA serotypes targeted by the drug or its metabolite. Thus, only rare individuals are predisposed to develop SCARs in response to a particular drug on the bases of their expression of HLA serotypes. Studies have identified several HLA serotypes associated with development of the DRESS syndrome in response to certain drugs, have developed tests to identify individuals who express some of these serotypes, and thereby have identified individuals who should avoid certain DRESS syndrome-inducing drugs.