The metabolism of sildenafil is facilitated primarily by the CYP3A4 hepatic microsomal isoenzymes and to a minor extent, via the CYP2C9 hepatic isoenzymes. The predominant circulating metabolite results from the N-demethylation of sildenafil. This particular resultant metabolite possesses a phosphodiesterase selectivity that is similar to the parent sildenafil molecule and a corresponding in vitro potency for PDE5 that is approximately 50% that of the parent drug. Moreover, plasma concentrations of the metabolite are about 40% of those recorded for sildenafil, a percentage that accounts for about 20% of sildenafil’s pharmacologic effects. This primary N-desmethyl metabolite of sildenafil also undergoes further metabolism, with a terminal half-life of about 4 hours. In patients with pulmonary arterial hypertension, plasma concentrations of the primary N-desmethyl metabolite are about 72% those of the original parent sildenafil molecule after a regimen of 20 mg three times a day - which is consequently responsible for about a 36% contribution to sildenafil’s overall pharmacological effects.
Sildenafil is cleared predominantly by the CYP3A4 (major route) and CYP2C9 (minor route) hepatic microsomal isoenzymes. The major circulating metabolite results from N-desmethylation of sildenafil, and is itself further metabolized. This metabolite has a phosphodiesterase (PDE) selectivity profile similar to sildenafil and an in vitro potency for phosphodiesterase type 5 (PDE-5) approximately 50% of the parent drug. Plasma concentrations of this metabolite are approximately 40% of those seen for sildenafil, so that the metabolite accounts for about 20% of sildenafil's pharmacologic effects.
Pharmacokinetics were studied in mouse, rat, rabbit, dog and man after single intravenous and/or oral doses of sildenafil or (14)C-sildenafil (Viagra). .... Five principal pathways of metabolism in all species were piperazine N-demethylation, pyrazole N-demethylation, loss of a two-carbon fragment from the piperazine ring (N,N'-deethylation), oxidation of the piperazine ring and aliphatic hydroxylation. Additional metabolites arose through combinations of these pathways. Sildenafil was the major component detected in human plasma. Following oral doses, AUC (infinity) for the piperazine N-desmethyl and piperazine N,N'-desethyl metabolites were 55 and 27% that of parent compound respectively.
Sildenafil is eliminated mainly in the feces as metabolites. In healthy adults and those with erectile dysfunction, approximately 80% of an oral dose is excreted as metabolites in feces and 13% is excreted in urine. In feces, the N-dealkylated, hydroxylated, N-demethylated, and N-dealkylated/demethylated metabolites of sildenafil comprise about 22, 13, 3, and 3% of total fecal excretion. In healthy individuals, sildenafil is excreted in urine mainly as the hydroxylated metabolite, with this metabolite representing about 41% of total urinary excretion of the drug.
/Sprague Dawley rats (10/sex/dose) were administered 10, 45 or 200 mg/kg/day of sildenafil for 1 month by oral gavage./ Plasma concentrations of sildenafil were higher in females than in males, while concentrations of the metabolite, UK-103,320, were higher in males than in females. As a result, females were exposed predominantly to the unchanged drug and males to an almost equal balance of drug and metabolite. These data indicate that N-demethylation of sildenafil to UK-103,320 is an important route of sildenafil biotransformation in male rats. Concentrations of UK-95,340 were generally below the limit of determination (30 ng/mL). ... /From table/
In single-dose volunteer studies of doses up to 800 mg, adverse reactions were similar to those seen at lower doses, but the incidence rates and severities were increased. Doses of 200 mg did not result in increased efficacy but the incidence of adverse reaction (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased. Due to the lack of data on the effect of sildenafil indicated for the treatment of pulmonary arterial hypertension (PAH) in pregnant women, sildenafil is not recommended for women of childbearing potential unless also using appropriate contraceptive measures. The safety and efficacy of sildenafil indicated for treating PAH in a woman during labor and delivery have not been studied. Caution should ultimately be exercised when sildenafil is administered to nursing women as it is not known if sildenafil or its metabolites are excreted in human breast milk. The safety and efficacy of sildenafil for the treatment of PAH in children below 1 year of age has not been established as no data is available. Clinical experience with the elderly population in the use of sildenafil for the treatment of PAH has been varied. Some reports suggest that there are no identified differences in responses between elderly and younger patients while others have documented that clinical efficacy as measured by 6-minute walk distance could be less in elderly patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Conversely, when sildenafil was used to treat erectile dysfunction in healthy elderly volunteers (65 years or over), a reduced clearance of sildenafil was observed. This reduction resulted in about 90% higher plasma concentrations of sildenafil and the active N-desmethyl metabolite compared to those seen in healthy younger volunteers (18-45 years). Due to age-differences in plasma protein binding, the corresponding increase in free sildenafil plasma concentration was approximately 40%. Sildenafil was not carcinogenic when administered to rats for 24 months at a dose resulting in total systemic drug exposure (AUCs) for unbound sildenafil and its major metabolite of 29- and 42- times, for male and female rats, respectively, the exposures observed in human males given the Maximum Recommended Human Dose (MRHD) of 100 mg. Sildenafil was not carcinogenic when administered to mice for 18-21 months at dosages up to the Maximum Tolerated Dose (MTD) of 10 mg/kg/day, approximately 0.6 times the MRHD on a mg/m2 basis. Sildenafil was negative in in vitro bacterial and Chinese hamster ovary cell assays to detect mutagenicity, and in vitro human lymphocytes and in vivo mouse micronucleus assays to detect clastogenicity. There was no impairment of fertility in rats given sildenafil up to 60 mg/kg/day for 36 days to females and 102 days to males, a dose producing an AUC value of more than 25 times the human male AUC.
IDENTIFICATION AND USE: Sildenafil is a white to off-white crystalline powder that is formulated into film-coated tablets, oral suspension, and parenteral injection. Sildenafil is a phosphodiesterase-5 (PDE-5) inhibitor. It is used both for the treatment of erectile dysfunction and for the treatment of pulmonary arterial hypertension (PAH) in adults to improve exercise ability and delay clinical worsening. HUMAN EXPOSURE AND TOXICITY: In general, overdosage of sildenafil may be expected to produce effects that are extensions of common adverse reactions. In studies of healthy individuals receiving single sildenafil doses up to 800 mg, the types of adverse events (e.g., decreased blood pressure, syncope, and prolonged erection) observed were similar to those observed at lower doses, but the incidences were increased. Serious adverse effects have also been reported at therapeutic dose levels including sudden decrease or loss of hearing, sudden loss of vision in one or both eyes, and prolonged erection lasting greater than 4 hours or priapism (a painful erection lasting greater than 6 hours). Serious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of sildenafil for erectile dysfunction. Most, but not all, of these patients had preexisting cardiovascular risk factors. Therefore it was not possible to determine whether these events were related directly to sildenafil, to sexual activity, to the patient's underlying cardiovascular disease, to a combination of these factors, or to other factors. The use of sildenafil is not recommended in children. In a long-term trial in pediatric patients with PAH, an increase in mortality with increasing sildenafil dose was observed. Pulmonary vasodilators such as sildenafil may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease. Sildenafil profoundly potentiates the vasodilatory effects of organic nitrates and nitrites. The drug did not exhibit clastogenic potential in an in vitro human lymphocytes test system. ANIMAL STUDIES: Lethality after oral administration occurred at 1000 mg/kg and 500 mg/kg in rats and 1000 mg/kg in mice. Female rats were more affected than male rats. Acute sildenafil treatment stimulated testosterone production in adult male rats. There was no impairment of fertility in rats given sildenafil up to 60 mg/kg/day for 36 days to females and 102 days to males. However, in another study male rats were gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (approximately 33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. No evidence of teratogenicity, embryotoxicity or fetotoxicity was observed in rats and rabbits which received up to 200 mg/kg/day during organogenesis. In another study, adult male rabbits received sildenafil at doses up to 9 mg/kg/day for 4 weeks to investigate the testicular histological alterations induced by overdoses of this drug. Abnormality in the germinal epithelium of the seminiferous tubules included spermatocytes karyopyknosis, spermatocytes degeneration, desquamation, spermatid giant cells and arrest of spermatogenesis. Additionally, increased Leydig cells cellularity, tubular degeneration, thickening of the interstitium were also observed. The encountered histological findings indicate that chronic exposure to sildenafil overdoses produces significant morphological and histological alterations in the testes which finally might lead to complete arrest of spermatogenesis. There was no evidence of carcinogenicity when sildenafil was administered orally to rats and mice for up to two years. Sildenafil did not exhibit evidence of mutagenicity in vitro in bacterial and Chinese hamster ovary cell assays. The drug also did not exhibit clastogenic potential in vivo in the mouse micronucleus test. Sildenafil is cleared predominantly by the CYP3A4 (major route) and CYP2C9 (minor route) hepatic microsomal isoenzymes. The major circulating metabolite results from N-desmethylation of sildenafil, and is itself further metabolized. This metabolite has a phosphodiesterase (PDE) selectivity profile similar to sildenafil and an in vitro potency for phosphodiesterase type 5 (PDE-5) approximately 50% of the parent drug. Plasma concentrations of this metabolite are approximately 40% of those seen for sildenafil, so that the metabolite accounts for about 20% of sildenafil's pharmacologic effects.
There have been at least 5 reports of acute liver injury attibuted to sildenafil use, but no instances of acute hepatic failure. The latency in most reports has been unclear because of the intermittent and sometimes unacknowledged use of sildenafil, but appears to be within 1 to 8 weeks. The pattern of serum enzyme elevations has ranged from hepatocellular to cholestatic, sometimes evolving from one to the other. The most convincing cases have been a mild cholestatic or "mixed" hepatitis arising within 1 to 3 months of starting sildenafil. Immunoallergic features and autoantibodies were not observed. Cases of acute onset with high serum aminotransferase levels have been reported after use of sildenafil that have some characteristics of ischemic injury. In other instances, the pattern of injury suggested anabolic steroid use. In two cases, re-exposure did not result in recurrence. Thus, the hepatotoxicity of sildenafil is not completely convincing and must be quite rare, if it occurs at all.
Sildenafil is known to be quickly absorbed, with maximum plasma concentrations being observed within 30-120 minutes (with a median of 60 minutes) of oral administration in a fasting patient. Moreover, the mean absolute bioavailability observed for sildenafil is about 41% (from a range of 25-63%). In particular, after oral three times a day dosing of sildenafil, the AUC and Cmax increase in proportion with dose over the recommended dosage range of 25-100 mg. When used in pulmonary arterial hypertension patients, however, the oral bioavailability of sildenafil after a dosing regimen of 80 mg three times a day, was on average 43% greater than compared to the lower doses. Finally, if sildenafil is administered orally with food, the rate of absorption is observed to be decreased with a mean delay in Tmax of about 60 minutes and a mean decrease in Cmax of approximately 29%. Regardless, the extent of absorption is not observed to be significantly affected as the recorded AUC decreased by only about 11 %.
After either oral or intravenous administration, sildenafil is excreted as metabolites predominantly in the feces (approximately 80% of the administered oral dose) and to a lesser extent in the urine (approximately 13% of the administered oral dose).
来源:DrugBank
吸收、分配和排泄
分布容积
西地那非的平均稳态分布体积约为105升——这个值表明该药物在组织中分布。
The mean steady-state volume of distribution documented for sildenafil is approximately 105 L - a value which suggests the medication undergoes distribution into the tissues.
来源:DrugBank
吸收、分配和排泄
清除
西地那非的全身清除率记录为41升/小时。
The total body clearance documented for sildenafil is 41 L/h.
Sildenafil is rapidly and almost completely absorbed following oral administration. Bioequivalence has been established between the 20-mg tablet and the 10-mg/mL oral suspension when administered as a single oral dose of 20 mg. Although single-dose studies indicate that more than 90% of an oral sildenafil dose is absorbed from the GI tract, the drug undergoes extensive metabolism in the GI mucosa during absorption and on first pass through the liver, with only about 40% of a dose reaching systemic circulation unchanged. Pharmacokinetics of the drug (as determined by peak plasma concentrations or area under the plasma concentration-time curve (AUC)) are dose proportional over the single-dose range of 1.25-200 mg. Peak plasma concentrations of sildenafil and its active N-desmethyl metabolite are achieved within 30-120 (median: 60) minutes following oral administration in fasting adults.
[EN] NOVEL DUAL MODE OF ACTION SOLUBLE GUANYLATE CYCLASE ACTIVATORS AND PHOSPHODIESTERASE INHIBITORS AND USES THEREOF [FR] NOUVEAUX ACTIVATEURS DE LA GUANYLATE CYCLASE SOLUBLES À DOUBLE MODE D'ACTION, INHIBITEURS DE PHOSPHODIESTÉRASE ET LEURS UTILISATIONS
DISUBSTITUTED TRIFLUOROMETHYL PYRIMIDINONES AND THEIR USE
申请人：BAYER PHARMA AKTIENGESELLSCHAFT
公开号：US20160221965A1
公开（公告）日：2016-08-04
The present application relates to novel 2,5-disubstituted 6-(trifluoromethyl)pyrimidin-4(3H)-one derivatives, to processes for their preparation, to their use alone or in combinations for the treatment and/or prevention of diseases, and to their use for preparing medicaments for the treatment and/or prevention of diseases, in particular for treatment and/or prevention of cardiovascular, renal, inflammatory and fibrotic diseases.
Compositions for Treatment of Cystic Fibrosis and Other Chronic Diseases
申请人：Vertex Pharmaceuticals Incorporated
公开号：US20150231142A1
公开（公告）日：2015-08-20
The present invention relates to pharmaceutical compositions comprising an inhibitor of epithelial sodium channel activity in combination with at least one ABC Transporter modulator compound of Formula A, Formula B, Formula C, or Formula D. The invention also relates to pharmaceutical formulations thereof, and to methods of using such compositions in the treatment of CFTR mediated diseases, particularly cystic fibrosis using the pharmaceutical combination compositions.
[EN] CALPAIN MODULATORS AND THERAPEUTIC USES THEREOF<br/>[FR] MODULATEURS DE CALPAÏNE ET LEURS UTILISATIONS THÉRAPEUTIQUES
申请人：BLADE THERAPEUTICS INC
公开号：WO2019190885A1
公开（公告）日：2019-10-03
Small molecule calpain modulator compounds, including their pharmaceutically acceptable salts, can be included in pharmaceutical compositions. The compounds can be useful in inhibiting calpain, or competitive binding with calpastatin, by contacting them with CAPN1, CAPN2, and/or CAPN9 enzymes residing inside a subject. The compounds and composition can also be administered to a subject in order to treat a fibrotic disease or a secondary disease state or condition of a fibrotic disease.
NOVEL GLUCOKINASE ACTIVATORS AND METHODS OF USING SAME
申请人：Ryono Denis E.
公开号：US20080009465A1
公开（公告）日：2008-01-10
Compounds are provided which are phosphonate and phosphinate activators and thus are useful in treating diabetes and related diseases and have the structure
wherein
is a heteroaryl ring;
R
4
is —(CH
2
)
n
-Z-(CH
2
)
m
—PO(OR
7
)(OR
8
), —(CH
2
)
n
Z-(CH
2
)
m
—PO(OR
7
)R
g
, —(CH
2
)
n
-Z-(CH
2
)
m
—OPO(OR
7
)R
g
, —(CH
2
)
n
Z—(CH
2
)
m
—OPO(R
9
)(R
10
), or —(CH
2
)
n
Z—(CH
2
)
m
—PO(R
9
)(R
10
);
R
5
and R
6
are independently selected from H, alkyl and halogen;
Y is R
7
(CH
2
)
s
or is absent; and
X, n, Z, m, R
4
, R
5
, R
6
, R
7
, and s are as defined herein; or a pharmaceutically acceptable salt thereof.
A method for treating diabetes and related diseases employing the above compounds is also provided.
提供了磷酸酯和磷酸酯激活剂，因此在治疗糖尿病和相关疾病方面非常有用，并具有以下结构：
其中
是杂环芳基环；
R
4
为—(CH
2
)
n
-Z-(CH
2
)
m
—PO(OR
7
)(OR
8
)、—(CH
2
)
n
Z-(CH
2
)
m
—PO(OR
7
)R
g
、—(CH
2
)
n
-Z-(CH
2
)
m
—OPO(OR
7
)R
g
、—(CH
2
)
n
Z—(CH
2
)
m
—OPO(R
9
)(R
10)
或—(CH
2
)
n
Z—(CH
2
)
m
—PO(R
9
)(R
10)
；
R
5
和R
6
分别选择自H、烷基和卤素；
Y为R
7
(CH
2
)
s
或不存在；以及
X、n、Z、m、R
4
、R
5
、R
6
、R
7
和s如本文所定义；或其药用盐。
还提供了一种利用上述化合物治疗糖尿病和相关疾病的方法。
PYRIMIDINYL AND 1,3,5-TRIAZINYL BENZIMIDAZOLES AND THEIR USE IN CANCER THERAPY
申请人：Rewcastle Gordon William
公开号：US20110009405A1
公开（公告）日：2011-01-13
Provided herein are pyrimidinyl and 1,3,5-triazinyl benzimidazoles of Formula I, and their pharmaceutical compositions, preparation, and use as agents or drugs for cancer therapy, either alone or in combination with radiation and/or other anticancer drugs.
