Both the N-demethylation and hydroxylation pathways of theophylline biotransformation are capacity-limited. Due to the wide intersubject variability of the rate of theophylline metabolism, non-linearity of elimination may begin in some patients at serum theophylline concentrations <10 mcg/mL. Since this non-linearity results in more than proportional changes in serum theophylline concentrations with changes in dose, it is advisable to make increases or decreases in dose in small increments in order to achieve desired changes in serum theophylline concentrations. Accurate prediction of dose-dependency of theophylline metabolism in patients a priori is not possible, but patients with very high initial clearance rates (i.e., low steady-state serum theophylline concentrations at above average doses) have the greatest likelihood of experiencing large changes in serum theophylline concentration in response to dosage changes. /Theophylline/
Caffeine and 3-methylxanthine are the only theophylline metabolites with pharmacologic activity. 3-methylxanthine has approximately one tenth the pharmacologic activity of theophylline and serum concentrations in adults with normal renal function are <1 ug/mL. In patients with end-stage renal disease, 3-methylxanthine may accumulate to concentrations that approximate the unmetabolized theophylline concentration. Caffeine concentrations are usually undetectable in adults regardless of renal function. In neonates, caffeine may accumulate to concentrations that approximate the unmetabolized theophylline concentration and thus, exert a pharmacologic effect. /Theophylline/
Theophylline is metabolized by the liver to 1,3-dimethyluric acid, 1-methyluric acid, and 3-methylxanthine. ... Individuals metabolize theophylline at different rates; however, individual metabolism of the drug is generally reproducible. Theophylline and its metabolites are excreted mainly by the kidneys. Renal clearance of the drug, however, contributes only 8-12% of the overall plasma clearance of theophylline. Small amounts of theophylline are excreted in feces unchanged. /Theophylline/
Theophylline is metabolized via the microsomal cytochrome p450 system, primarily by the isozyme CYP1A2. The major pathway is demethylation to 3-methylxanthine in addition to being demethylated or oxidized to other metabolites. Less than 10% of theophylline is excreted in the urine unchanged. /Theophylline/
Following oral dosing, theophylline does not undergo any measurable first-pass elimination. In adults and children beyond one year of age, approximately 90% of the dose is metabolized in the liver. Biotransformation takes place through demethylation to 1-methylxanthine and 3-methylxanthine and hydroxylation to 1,3-dimethyluric acid. 1-methylxanthine is further hydroxylated, by xanthine oxidase, to 1-methyluric acid. About 6% of a theophylline dose is N-methylated to caffeine. Theophylline demethylation to 3-methylxanthine is catalyzed by cytochrome P-450 1A2, while cytochromes P-450 2E1 and P-450 3A3 catalyze the hydroxylation to 1,3-dimethyluric acid. Demethylation to 1-methylxanthine appears to be catalyzed either by cytochrome P-450 1A2 or a closely related cytochrome. In neonates, the N-demethylation pathway is absent while the function of the hydroxylation pathway is markedly deficient. The activity of these pathways slowly increases to maximal levels by one year of age. /Theophylline/
IDENTIFICATION AND USE: Aminophylline is white or slightly yellowish granules or powder. Aminophylline is prepared from theophylline and aqueous ethylenediamine. It is used as bronchodilator agent. HUMAN EXPOSURE AND TOXICITY: Aminophylline can trigger seizures in patients without known underlying epilepsy or added risk factor for seizure exacerbation in epilepsy. Most of these seizures are difficult to control and are underappreciated compared to other drug toxicities. Despite a long clinical history of aminophylline-induced seizures, relatively little is known about the underlying molecular mechanisms that contribute to methylxanthine-induced seizure generation. Fatalities in adults have generally occurred during or following IV administration of large doses of aminophylline in patients with renal, hepatic, or cardiovascular complications. In other patients, the rapidity of the injection, rather than the dose used, appears to be the more important factor precipitating acute hypotension, seizures, coma, cardiac standstill, ventricular fibrillation, and death. IV aminophylline or theophylline should therefore be given slowly. In children, fatalities usually are a result of overdosage and marked sensitivity to the CNS stimulation of theophylline. There are some reports of aminophylline hypersensitivity reaction and the most cases were delayed type reaction in English literatures. However, most of Japanese cases were immediate type. Acetylation is a main metabolic pathway of ethylenediamine. Most of Japanese have a rapid or intermediate acetylators on the other hand. Caucasian have a 50% likelihood of being slow acetylators. This difference suggest the different incidences of immediate and delayed reaction of aminophylline hypersensitivity reaction in Japanese and Caucasian respectively. Aminophylline treatment might be associated with elevated levels of myocardial enzymes. In vitro, aminophylline protected apoptosis of MRC-5 cells through the inactivation of caspases 3 and 8. ANIMAL STUDIES: Aminophylline (100-250 mg/kg) consistently induced seizures and post-ictal mortality in mice, and conventional anticonvulsants and adenosine agonists were ineffective in antagonizing them. Biochemical assay of brain homogenates showed that aminophylline seizures were associated with enhancements in brain malone dialdehyde and nitric oxide metabolites levels, whereas, superoxide dismutase activity was reduced, and these changes were attenuated after melatonin and L-NAME pretreatment. Aminophylline induced convulsions in rats in a dose-dependent manner, and both incidence of seizure and mortality were maximum at 300 mg/kg and there was significant increase of free radical generation. Pre-treatment with antioxidants showed differential attenuating effects on aminophylline induced free radical generation, but they were very much ineffective in antagonizing aminophylline induced seizures and post-seizure mortality by any appreciable extent. In pregnant rabbits, aminophylline treatment produced no acceleration in general anatomic lung development, as reflected in the ratio of lung air-space capacity to lung tissue weight. Under similar experimental conditions, maternal caffeine treatment had no effect on fetal rabbit lungs. In other experiment, pregnant rabbit does were treated intravenously with aminophylline (6 mg/kg/day) from the twenty-fifth day after the day of mating, and the fetuses were delivered by hysterotomy on the twenty-eighth day. One group of neonates was breathing air, and another group 100% oxygen. Lung mechanics were evaluated in the newborn animals during spontaneous or artificial ventilation, and the lungs were studied histologically with particular reference to the alveolar volume density. Aminophylline-treated litters had greater body weights, an improved survival rate, and an increased amount of phosphatidylglycerol in lung lavage fluid. Respiratory frequency was increased in aminophylline-treated animals breathing air, but data on lung compliance showed no significant difference between treated and control animals. It was concluded that the beneficial effect of aminophylline can be attributed largely to a combination of accelerated fetal growth and improved postnatal regulation of breathing and less to a specific influence on the biochemical and functional maturation of the lung. Aminophylline, exacerbated seizure-induced damage in the developing brain in rats.
参考文献:M Chen, V Vijay, Q Shi, Z Liu, H Fang, W Tong. 美国食品药品监督管理局批准的药物标签用于研究药物诱导的肝损伤,《药物发现今日》,16(15-16):697-703, 2011. PMID:21624500 DOI:10.1016/j.drudis.2011.05.007
M Chen, A Suzuki, S Thakkar, K Yu, C Hu, W Tong. DILIrank:按人类发展药物诱导肝损伤风险排名的最大参考药物清单。《药物发现今日》2016, 21(4): 648-653. PMID:26948801 DOI:10.1016/j.drudis.2016.02.015
References:M Chen, V Vijay, Q Shi, Z Liu, H Fang, W Tong. FDA-Approved Drug Labeling for the Study of Drug-Induced Liver Injury, Drug Discovery Today, 16(15-16):697-703, 2011. PMID:21624500 DOI:10.1016/j.drudis.2011.05.007
M Chen, A Suzuki, S Thakkar, K Yu, C Hu, W Tong. DILIrank: the largest reference drug list ranked by the risk for developing drug-induced liver injury in humans. Drug Discov Today 2016, 21(4): 648-653. PMID:26948801 DOI:10.1016/j.drudis.2016.02.015
IV theophylline produces the highest and most rapid serum theophylline concentration. Following a single IV dose of theophylline (as aminophylline) of about 5 mg/kg over 30 minutes to healthy adults, mean peak serum theophylline concentrations of about 10 ug/mL are reached.
In neonates, approximately 50% of the theophylline dose is excreted unchanged in the urine. Beyond the first three months of life, approximately 10% of the theophylline dose is excreted unchanged in the urine. /Theophylline/
When administered IM, theophylline is usually absorbed slowly and incompletely. Rectal suppositories (no longer commercially available in the US) are slowly and erratically absorbed, regardless of whether the suppository base is hydrophilic or lipophilic. /Theophylline/
[EN] NOVEL COMPOUNDS AND PHARMACEUTICAL COMPOSITIONS THEREOF FOR THE TREATMENT OF INFLAMMATORY DISORDERS<br/>[FR] NOUVEAUX COMPOSÉS ET COMPOSITIONS PHARMACEUTIQUES LES COMPRENANT POUR LE TRAITEMENT DE TROUBLES INFLAMMATOIRES
申请人:GALAPAGOS NV
公开号:WO2017012647A1
公开(公告)日:2017-01-26
The present invention discloses compounds according to Formula (I), wherein R1, R3, R4, R5, L1, and Cy are as defined herein. The present invention also provides compounds, methods for the production of said compounds of the invention, pharmaceutical compositions comprising the same and their use in allergic or inflammatory conditions, autoimmune diseases, proliferative diseases, transplantation rejection, diseases involving impairment of cartilage turnover, congenital cartilage malformations, and/or diseases associated with hypersecretion of IL6 and/or interferons. The present invention also methods for the prevention and/or treatment of the aforementioned diseases by administering a compound of the invention.
The present invention relates compounds of the formula: or pharmaceutically acceptable salts thereof, useful as sodium channel blockers, as well as compositions containing the same, processes for the preparation of the same, and therapeutic methods of use therefore in promoting hydration of mucosal surfaces and the treatment of diseases including cystic fibrosis, chronic obstructive pulmonary disease, asthma, bronchiectasis, acute and chronic bronchitis, emphysema, and pneumonia.
CHLORO-PYRAZINE CARBOXAMIDE DERIVATIVES WITH EPITHELIAL SODIUM CHANNEL BLOCKING ACTIVITY
申请人:Parion Sciences, Inc.
公开号:US20140171447A1
公开(公告)日:2014-06-19
This invention provides compounds of the formula I:
and their pharmaceutically acceptable salts, useful as sodium channel blockers, compositions containing the same, therapeutic methods and uses for the same and processes for preparing the same.
The present invention provides compounds, compositions thereof, and methods of using the same.
本发明提供了化合物、其组合物以及使用这些化合物的方法。
SUBSTITUTED INDOLES
申请人:Gant Thomas G.
公开号:US20090191183A1
公开(公告)日:2009-07-30
Disclosed herein are substituted indole cysteinyl leukotriene receptor modulators of Formula I, process of preparation thereof, pharmaceutical compositions thereof, and methods of use thereof.