Recent studies have provided spectral evidence for presence of inhibitory product-cytochrome P450 complexes formed from ... /metabolism of benzphetamine/. ... Complexes ... thought to reduce ... the amount of co-complexing cytochrome and to inhibit metabolism by noncompetitive mechanism.
The following pathway for metabolism of benzphetamine (bz) in rat hepatic microsomes was established: benzphetamine yields norbenzphetamine (norbz), n-hydroxynorbenzphetamine, n-benzylethyl-alpha-phenylnitrone, & 2-nitroso-1-phenylpropane. The latter product forms a complex with cytochrome p450 with an absorbance max at 455 nm. Steps 1, 2, & 4 are cytochrome p450-dependent; step 3 appears to involve the flavoprotein mixed-function amine oxidase. Step 2 is partially uncoupled, producing hydrogen peroxide at approx 3 times the rate of n-hydroxylation. Benzphetamine is oxidized to norbz in microsomes from both untreated rats (u-microsomes) & phenobarbital (pb)-treated rats, but 455-nm peak does not appear in u-microsomes until almost all of the benzphetamine has been converted to norbz, ie, benzphetamine inhibits the oxidation of norbz in u- but not in phenobarbital-microsomes. The inhibition is competitive. Benzphetamine inhibits the oxidation of nitrone to 2-nitroso-a-phenylpropane in both u- & phenobarbital-microsomes; norbz inhibits this reaction in u-microsomes only.
Electrophoretically homogeneous cytochrome p450lm2 isolated from phenobarbital-induced rabbits & p450lm4 isolated from beta-naphthoflavone-induced animals differed in the higher activity of the former toward benzphetamine & p-nitrophenetole.
IDENTIFICATION: Benzphetamine is a centrally acting antiobesity agent. Benzphetamine is a clear liquid which is insoluble in water. Soluble in ethanol, methanol, chloroform, acetone, ether or benzene. Benzphetamine hydrochloride is a solid crystalline material. HUMAN EXPOSURE: Main risks and target organs: Acute central nervous system stimulation, cardiotoxicity causing tachycardia, arrhythmias, hypertension and cardiovascular collapse. High risk of dependency and abuse. Cardiovascular: Palpitation, chest pain, tachycardia, arrhythmias and hypertension are common; cardiovascular collapse can occur in severe poisoning. Myocardial ischemia, infarction and ventricular dysfunction are described. Central Nervous System (CNS): Stimulation of CNS, tremor, restlessness, agitation, insomnia, increased motor activity, headache, convulsions, coma and hyperreflexia are described. Stroke and cerebral vasculitis have been observed. Gastrointestinal: Vomiting, diarrhea and cramps may occur. Acute transient ischemic colitis has occurred with chronic methamphetamine abuse. Genitourinary: Increased bladder sphincter tone may cause dysuria, hesitancy and acute urinary retention. Renal failure can occur secondary to dehydration or rhabdomyolysis. Renal ischemia may be noted. Dermatologic: Skin is usually pale and diaphoretic, but mucous membranes appear dry. Endocrine: Transient hyperthyroxinemia may be noted. Metabolism: Increased metabolic and muscular activity may result in hyperventilation and hyperthermia. Weight loss is common with chronic use. Fluid/Electrolyte: Hypo- and hyperkalemia have been reported. Dehydration is common. Musculoskeletal: Fasciculations and rigidity may be noted. Rhabdomyolysis is an important consequence of severe amphetamine poisoning. Psychiatric: Agitation, confusion, mood elevation, increased wakefulness, talkativeness, irritability and panic attacks are typical. Chronic abuse can cause delusions and paranoia. A withdrawal syndrome occurs after abrupt cessation following chronic use. Contraindications to its use included: Anorexia, insomnia, psychopathic personality disorders, suicidal tendencies, Gilles de la Tourette syndrome and other disorders, hyperthyroidism, narrow angle glaucoma, diabetes mellitus and cardiovascular diseases such as angina, hypertension and arrythmias. Oral: Readily absorbed from the gastro-intestinal tract and buccal mucosa. It is resistant to metabolism by monoamine oxidase. Inhalation: Amphetamine is rapidly absorbed by inhalation and is often abused by this route. Absorption by route of exposure: Amphetamine is rapidly absorbed after oral ingestion. Peak plasma levels occur within 1 to 3 hours, varying with the degree of physical activity and the amount of food in the stomach. Absorption is usually complete by 4 to 6 hours. Sustained release preparations are available as resin-bound, rather than soluble, salts. These compounds display reduced peak blood levels compared with standard amphetamine preparations, but total amounts absorbed and time to peak levels remain similar. Distribution by route of exposure: Amphetamines are concentrated in the kidney, lungs, cerebrospinal fluid and brain. They are highly lipid soluble and readily cross the blood-brain barrier. Protein binding and volume of distribution varies widely, but the average volume of distribution is 5 L/kg body weight. Biological half-life by route of exposure: Under normal conditions, about 30% of amphetamine is excreted unchanged in the urine but this excretion is highly variable and is dependent on urinary pH. When the urinary pH is acidic (pH 5.5 to 6.0), elimination is predominantly by urinary excretion with approximately 60% of a dose of amphetamine being excreted unchanged by the kidney within 48 hours. When the urinary pH is alkaline (pH 7.5 to 8.0), elimination is predominantly by deamination (less than 7% excreted unchanged in the urine); the half-life ranging from 16 to 31 hours. Metabolism: The major metabolic pathway for amphetamine involves deamination by cytochrome P450 to para-hydroxyamphetamine and phenylacetone; this latter compound is subsequently oxidized to benzoic acid and excreted as glucuronide or glycine (hippuric acid) conjugate. Smaller amounts of amphetamine are converted to norephedrine by oxidation. Hydroxylation produces an active metabolite, O-hydroxynorephedrine, which acts as a false neurotransmitter and may account for some drug effect, especially in chronic users. Elimination and excretion: Normally 5 to 30% of a therapeutic dose of amphetamine is excreted unchanged in the urine by 24 hours, but the actual amount of urinary excretion and metabolism is highly pH dependent. Mode of action: Amphetamine appears to exert most or all of its effect in the CNS by causing release of biogenic amines, especially norepinephrine and dopamine, from storage sites in nerve terminals. It may also slow down catecholamine metabolism by inhibiting monoamine oxidase. The toxic dose varies considerably due to individual variations and the development of tolerance. Teratogenicity: The use of amphetamine for medical indications does not pose a significant risk to the fetus for congenital anomalies. Amphetamine congeners generally do not appear to be human teratogens. Mild withdrawal symptoms may be observed in the newborn, but the few studies of infant follow-up have not shown long-term sequelae, although more studies of this nature are needed. Illicit maternal use or abuse of amphetamine presents a significant risk to the fetus and newborn, including intrauterine growth retardation, premature delivery and the potential for increased maternal, fetal and neonatal morbidity. Interactions may include the following: Acetazolamide: administration may increase serum concentration of amphetamine. Alcohol: may increase serum concentration of amphetamine. Ascorbic acid: lowering urinary pH, may enhance amphetamine excretion Furazolidone: amphetamines may induce a hypertensive response in patients taking furazolidone. Guanethidine: amphetamine inhibits the antihypertensive response to guanethidine. Haloperidol: limited evidence indicates that haloperidol may inhibit the effects of amphetamine but the clinical importance of this interaction is not established. Lithium carbonate: isolated case reports indicate that lithium may inhibit the effects of amphetamine. Monoamine oxidase inhibitor: severe hypertensive reactions have followed the administration of amphetamine congeners to patients taking monoamine oxidase inhibitors. Norepinephrine: amphetamine abuse may enhance the pressor response to norepinephrine. Phenothiazines: amphetamine may inhibit the antipsychotic effect of phenothiazines, and phenothiazines may inhibit the anorectic effect of amphetamines. Sodium bicarbonate: large doses of sodium bicarbonate inhibit the elimination of amphetamine, thus increasing the amphetamine effect. Tricyclic antidepressants: theoretically increases the effect of amphetamine, but clinical evidence is lacking.
Although the mechanism of action of the sympathomimetic appetite suppressants in the treatment of obesity is not fully known, these medications have pharmacological effects similar to those of amphetamines. Amphetamine and related sympathomimetic medications (such as benzphetamine) are thought to stimulate the release of norepinephrine and/or dopamine from storage sites in nerve terminals in the lateral hypothalamic feeding center, thereby producing a decrease in appetite. This release is mediated by the binding of benzphetamine to centrally located adrenergic receptors.
[EN] METHYL OXAZOLE OREXIN RECEPTOR ANTAGONISTS<br/>[FR] MÉTHYLOXAZOLES ANTAGONISTES DU RÉCEPTEUR DE L'OREXINE
申请人：MERCK SHARP & DOHME
公开号：WO2016089721A1
公开（公告）日：2016-06-09
The present invention is directed to methyl oxazole compounds which are antagonists of orexin receptors. The present invention is also directed to uses of the compounds described herein in the potential treatment or prevention of neurological and psychiatric disorders and diseases in which orexin receptors are involved. The present invention is also directed to compositions comprising these compounds. The present invention is also directed to uses of these compositions in the potential prevention or treatment of such diseases in which orexin receptors are involved.
The present invention relates to compounds of formula I
wherein R
1
to R
4
and G are as defined in the description and claims and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prevention of diseases which are associated with the modulation of H3 receptors.
The present invention relates to compounds of formula I
wherein A and R
1
to R
4
are as defined in the description and claims, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prevention of diseases which are associated with the modulation of H3 receptors.
BENZOFURAN AND BENZOTHIOPHENE-2-CARBOXYLIC ACID AMIDE DERIVATIVES
申请人：Mohr Peter
公开号：US20090029976A1
公开（公告）日：2009-01-29
The present invention relates to compounds of formula I
wherein X, A and R
1
to R
4
are as defined in the description and claims, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prevention of diseases which are associated with the modulation of H3 receptors.
Disclosed herein are new heterocyclic compounds of Formula IIa:
and compositions thereof, and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
