The metabolism of clonidine is poorly understood. The main reaction in clonidine metabolism is the 4-hydroxylation of clonidine by CYP2D6, CYP1A2, CYP3A4, CYP1A1, and CYP3A5. Clonidine is <50% metabolized in the liver to inactive metabolites.
Clonidine hydrochloride is metabolized in the liver. In humans, 4 metabolites have been detected but only one, the inactive p-hydroxyclonidine, has been identified.
...Seventeen cDNA-expressed P450 enzymes, in addition to pooled human liver microsomes, were evaluated for clonidine 4-hydroxylation activity in vitro. Five P450 enzymes-CYP2D6, 1A2, 3A4, 1A1, and 3A5-catalyzed measurable formation of 4-hydroxyclonidine. Selective inhibition studies in human liver microsomes confirmed that these isoforms are jointly responsible for 4-hydroxylation of clonidine in vitro, and CYP2D6 accounted for approximately two-thirds of the activity. The major role of CYP2D6 in clonidine metabolism might explain the increase in its nonrenal clearance during pregnancy.
CLONIDINE SHOWS SPECIES DIFFERENCES IN THE EXTENT OF BIOTRANSFORMATION. THE FATE OF (14)C-CLONIDINE IN THE DOG HAS BEEN REPORTED AND SIX COMPONENTS WERE ISOLATED AND IDENTIFIED. UNCHANGED CLONIDINE AND ITS P-HYDROXYLATED DERIVATIVE WERE DETECTED. DICHLOROPHENYLGUANIDINE, WHICH HAS PREVIOUSLY BEEN REPORTED AS A METABOLITE IN DOGS, WAS ALSO IDENTIFIED. THREE METABOLITES NOT PREVIOUSLY DESCRIBED WERE ALSO ISOLATED FROM DOG URINE. THE MAJOR METABOLIC ROUTES FOR CLONIDINE ARE PHENYL RING HYDROXYLATION AND SPLITTING OF THE IMIDAZOLIDINE RING. COMPARATIVE STUDIES SHOWED THAT THE METABOLISM OF CLONIDINE IS RATHER SIMILAR IN RAT, DOG, AND MAN, BUT MAN EXCRETED MOST UNCHANGED DRUG AND DOG SHOWED THE MOST EXTENSIVE METABOLISM.
Hepatic. Metabolized via minor pathways. The major metabolite, <i>p</i>-hydroxyclonidine, is present in concentrations less than 10% of those of unchanged clonidine in urine. Four metabolites have been detected, but only <i>p</i>-hydroxyclonidine has been identified.
Half Life: 6-20 hours; 40-60% is excreted in urine unchanged, 20% is excreted in feces. Less than 10% is excreted by <i>p</i>-hydroxyclonidine.
Clonidine acts as an agonist at presynaptic alpha(2)-receptors in the nucleus tractus solitarius of the medulla oblongata. Stimulation of these receptors results in the supression of efferent sympathetic pathways and the subsequent decrease in blood pressure and vascular tone in the heart, kidneys, and peripheral vasculature. Clonidine is also a partial agonist at presynaptic alpha(2)-adrenergic receptors of peripheral nerves in vascular smooth muscle.
Serum aminotransferase elevations during clonidine therapy are uncommon and rates of such elevations have not been reported in the large clinical trials, demonstrating its efficacy in hypertension. Despite many decades of use, clonidine has not been implicated in instances of clinically apparent acute liver injury.
Clonidine reaches maximum concentration in 60-90 minutes after oral administration. Race and fasting status do not influence pharmacokinetics of clonidine. A 100µg oral clonidine tablet reaches a Cmax of 400.72pg/mL with an AUC of 5606.78h\*pg/mL and a bioavailability of 55-87%.
来源:DrugBank
吸收、分配和排泄
消除途径
大约50%的可乐定剂量以未改变的药物形式通过尿液排出，20%通过粪便消除。
Approximately 50% of a clonidine dose is excreted in the urine as the unchanged drug and 20% is eliminated in the feces.
Animal studies indicate that clonidine is widely distributed into body tissues; tissue concentrations of the drug are higher than plasma concentrations. The mean volume of distribution of clonidine is reported to be 2.1 L/kg. After oral administration, highest concentrations of the drug are found in the kidneys, liver, spleen, and GI tract. High concentrations of the drug also appear in the lacrimal and parotid glands. Clonidine is concentrated in the choroid of the eye and is also distributed into the heart, lungs, testes, adrenal glands, fat, and muscle. The lowest concentration occurs in the brain. Clonidine is distributed into CSF. Following epidural infusion, clonidine is rapidly and extensively distributed into CSF and readily partitions into the plasma via epidural veins. In vitro, clonidine is approximately 20-40% bound to plasma proteins, mainly albumin. Clonidine crosses the placenta1 and is distributed into milk. In one lactating woman who received approximately 0.04 mg of oral clonidine hydrochloride twice daily and 25 mg of oral dihydralazine 3 times daily, clonidine concentrations were 0.33 ng/mL in a plasma sample obtained 1 hour after a dose and 0.6 ng/mL in a milk sample obtained 2.5 hours after a dose; the drug was not detected in the plasma of the infant 1 hour after nursing.
[EN] BENZAMIDE OR BENZAMINE COMPOUNDS USEFUL AS ANTICANCER AGENTS FOR THE TREATMENT OF HUMAN CANCERS<br/>[FR] COMPOSÉS BENZAMIDE OU BENZAMINE À UTILISER EN TANT QU'ANTICANCÉREUX POUR LE TRAITEMENT DE CANCERS HUMAINS
申请人：UNIV TEXAS
公开号：WO2017007634A1
公开（公告）日：2017-01-12
The described invention provides small molecule anti-cancer compounds for treating tumors that respond to cholesterol biosynthesis inhibition. The compounds selectively inhibit the cholesterol biosynthetic pathway in tumor-derived cancer cells, but do not affect normally dividing cells.
[EN] S-NITROSOMERCAPTO COMPOUNDS AND RELATED DERIVATIVES<br/>[FR] COMPOSÉS DE S-NITROSOMERCAPTO ET DÉRIVÉS APPARENTÉS
申请人：GALLEON PHARMACEUTICALS INC
公开号：WO2009151744A1
公开（公告）日：2009-12-17
The present invention is directed to mercapto-based and S- nitrosomercapto-based SNO compounds and their derivatives, and their use in treating a lack of normal breathing control, including the treatment of apnea and hypoventilation associated with sleep, obesity, certain medicines and other medical conditions.
SULFOXIMINE SUBSTITUTED QUINAZOLINES FOR PHARMACEUTICAL COMPOSITIONS
申请人：BLUM Andreas
公开号：US20140135309A1
公开（公告）日：2014-05-15
This invention relates to novel sulfoximine substituted quinazoline derivatives of formula I
wherein Ar, R
1
and R
2
are as defined herein, and their use as MNK1 (MNK1a or MNK1b) and/or MNK2 (MNK2a or MNK2b) kinase inhibitors, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment or amelioration of MNK1 (MNK1a or MNK1b) and/or MNK2 (MNK2a or MNK2b) mediated disorders.
[EN] SULFOXIMINE SUBSTITUTED QUINAZOLINES FOR PHARMACEUTICAL COMPOSITIONS<br/>[FR] QUINAZOLINES SUBSTITUÉES PAR SULFOXIMINE POUR COMPOSITIONS PHARMACEUTIQUES
申请人：BOEHRINGER INGELHEIM INT
公开号：WO2014072244A1
公开（公告）日：2014-05-15
This invention relates to novel sulfoximine substituted quinazoline derivatives of formula (I), wherein Ar, R1 and R2 are as defined in the description and claims, and their use as MNK1 (MNK1a or MNK1b) and/or MNK2 (MNK2a or MNK2b) kinase inhibitors, pharmaceutical compositions containing the same, and methods of using the same as agents for treatment or amelioration of MNK1 (MNK1a or MNK1b) and/or MNK2 (MNK2a or MNK2b) mediated disorders.
[EN] QUINONE BASED NITRIC OXIDE DONATING COMPOUNDS<br/>[FR] COMPOSÉS DONNEURS D'OXYDE NITRIQUE À BASE DE QUINONE
申请人：NICOX SA
公开号：WO2013060673A1
公开（公告）日：2013-05-02
The present invention relates to nitric oxide donor compounds having a quinone based structure, to processes for their preparation and to their use in the treatment of pathological conditions where a deficit of NO plays an important role in their pathogenesis.
