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Showing 151 - 160 of 1060 results

Miglustat, an N-alkylated imino sugar, is a synthetic analogue of D-glucose. Miglustat is an inhibitor of the enzyme glucosylceramide synthase, which is a glucosyl transferase enzyme responsible for catalyzing the formation of glucosylceramide (glucocerebroside). Glucosylceramide is a substrate for the endogenous glucocerebrosidase, an enzyme that is deficient in Gaucher's disease. The accumulation of glucosylceramide due to the absence of glucocerebrosidase results in the storage of this material in the lysosomes of tissue macrophages, leading to widespread pathology due to infiltration of lipid-engorged macrophages in the viscera, lymph nodes, and bone marrow. This results in secondary hematologic consequences including sever anemia and thrombocytopenia, in addition to the characteristic progressive hepatosplenomegaly, as well as skeletal complications including osteonecrosis and osteopenia with secondary pathological fractures. Miglustat functions as a competitive and reversible inhibitor of the enzyme glucosylceramide synthase, the initial enzyme in a series of reactions which results in the synthesis of most glycosphingolipids. The goal of treatment with miglustat is to reduce the rate of glycosphingolipid biosynthesis so that the amount of glycosphingolipid substrate is reduced to a level which allows the residual activity of the deficient glucocerebrosidase enzyme to be more effective (substrate reduction therapy), reducing the accumulation of glucocerebroside in macrophages. In vitro and in vivo studies have shown that miglustat can reduce the synthesis of glucosylceramide-based glycosphingolipids. In clinical trials, miglustat improved liver and spleen volume, as well as hemoglobin concentration and platelet count. Inhibition of glycosphingolipid synthesis has also shown to reduce intracellular lipid storage, improve fluid-phase endosomal uptake and normalize lipid transport in peripheral blood B lymphocytes of NP-C patients, which results in a decrease in the potentially neurotoxic accumulation of gnagliosides GM2 and GM3, lactosylceramide and glucosylceramide, possibly preventing further neuronal damage. Other studies have also suggested that miglustat may indirectly modulate intracellular calcium homeostasis through its effects on glucosylceramide levels, and evidence has shown that an initiating factor in the pathogenesis of NP-C may be impaired calcium homeostasis related to sphingosine storage. Therefore, the effect that miglustat exerts on intracellular calcium levels may influence an important underlying pathogenic mechanism of NP-C. Miglustat is used for the treatment of adult patients with mild to moderate type 1 (nonneuropathic) Gaucher's disease for whom enzyme replacement therapy is not a therapeutic option (e.g. due to constraints such as allergy, hypersensitivity, or poor venous access). Now approved in some countries for the treatment of progressive neurological symptoms in adult and pediatric patients with Niemann-Pick disease type C (NP-C). Miglustat is marketed under the trade name Zavesca.

Class (Stereo):
CHEMICAL (ACHIRAL)


Conditions:

Olmesartan medoxomil, a prodrug, is hydrolyzed to olmesartan during absorption from the gastrointestinal tract. Olmesartan is a selective AT1 subtype angiotensin II receptor antagonist. Olmesartan blocks the vasoconstrictor effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in vascular smooth muscle. Oral olmesartan medoxomil 10-40 mg once daily is recommended for the treatment of adult patients with hypertension, this dosage has consistently helped achieve a double-digit reduction both in systolic and diastolic blood pressure, a reduction which is maintained for one year. Extensive clinical evidence from several large well designed trials and the clinical practice setting has confirmed the antihypertensive efficacy and good tolerability profile of oral olmesartan medoxomil, as monotherapy in patients with hypertension. Olmesartan medoxomil has shown no clinically important pharmacokinetic interactions with digoxin, warfarin or antacid (aluminium magnesium hydroxide). Adverse events were infrequent in clinical studies of olmesartan medoxomil and were similar to those attributed to placebo.
Eletriptan (eletriptan hydrobromide, trade name Relpax) is a selective 5-hydroxytryptamine (5-HT1B/1D) serotonin receptor agonist (triptan) indicated for the acute treatment of migraine with or without aura in adults. Eletriptan binds with high affinity to 5-HT1B, 5-HT1D and 5-HT1F receptors, and has modest affinity for 5-HT1A, 5-HT1E, 5-HT2B and 5-HT7 receptors. The therapeutic activity of eletriptan for the treatment of migraine headache is thought to be due to the agonist effects at the 5-HT1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release. Eletriptan (Relpax) has been approved for use in the acute treatment of migraine in 51 countries and has been introduced in 17 countries including Mexico, Italy, France and Japan.

Class (Stereo):
CHEMICAL (ABSOLUTE)


Conditions:

Eplerenone, an aldosterone receptor antagonist similar to spironolactone, has been shown to produce sustained increases in plasma renin and serum aldosterone, consistent with inhibition of the negative regulatory feedback of aldosterone on renin secretion. The resulting increased plasma renin activity and aldosterone circulating levels do not overcome the effects of eplerenone. Eplerenone selectively binds to recombinant human mineralocorticoid receptors relative to its binding to recombinant human glucocorticoid, progesterone and androgen receptors. Eplerenone binds to the mineralocorticoid receptor and thereby blocks the binding of aldosterone (component of the renin-angiotensin-aldosterone-system, or RAAS). Aldosterone synthesis, which occurs primarily in the adrenal gland, is modulated by multiple factors, including angiotensin II and non-RAAS mediators such as adrenocorticotropic hormone (ACTH) and potassium. Aldosterone binds to mineralocorticoid receptors in both epithelial (e.g., kidney) and nonepithelial (e.g., heart, blood vessels, and brain) tissues and increases blood pressure through induction of sodium reabsorption and possibly other mechanisms. Used for improvement of survival of stable patients with left ventricular systolic dysfunction (ejection fraction <40%) and clinical evidence of congestive heart failure after an acute myocardial infarction.
Tizoxanide, the primary active metabolite of the FDA approved drug nitazoxanide, an anti-infective that has been approved for the treatment of diarrhea caused by Giardia lamblia. Tizoxanide, an active metabolite of nitazoxanide in humans, is also an antiparasitic drug of the thiazolide class. It has broad-spectrum antiparasitic and broad-spectrum antiviral properties. Besides, it has being found that Tizoxanide exhibits appreciable antagonist activity for both mGluR1 and mGluR5 (IC50 = 1.8 uM and 1.2 uM, respectively).
Nitisinone, 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) is a triketone with herbicidal activity. Orfadin® capsules contain nitisinone used in the treatment of hereditary tyrosinemia type 1 (HT-1). Nitisinone is a competitive inhibitor of 4-hydroxyphenyl-pyruvate dioxygenase, an enzyme upstream of fumarylacetoacetase in the tyrosine catabolic pathway. By inhibiting the normal catabolism of tyrosine in patients with HT-1, nitisinone prevents the accumulation of the catabolic intermediates maleylacetoacetate and fumarylacetoacetate. In patients with HT-1, these catabolic intermediates are converted to the toxic metabolites succinylacetone and succinylacetoacetate, which are responsible for the observed liver and kidney toxicity. Succinylacetone can also inhibit the porphyrin synthesis pathway leading to the accumulation of 5-aminolevulinate, a neurotoxin responsible for the porphyric crises characteristic of HT-1. Zeneca Agrochemicals and Zeneca Pharmaceuticals made NTBC available for clinical use and, with the approval of the Swedish Medical Products Agency, a seriously ill child with an acute form of tyrosinaemia type 1 was successfully treated in February 1991. Nitisinone is investigated as a potential treatment for other disorders of tyrosine metabolism including alkaptonuria.
Escitalopram is one of a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Escitalopram, also known by the brand names Lexapro and Cipralex among others, is an antidepressant. The mechanism of antidepressant action of escitalopram, the S-enantiomer of racemic citalopram, is presumed to be linked to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT). In vitro and in vivo studies in animals suggest that escitalopram is a highly selective serotonin reuptake inhibitor (SSRI) with minimal effects on norepinephrine and dopamine neuronal reuptake. Escitalopram is at least 100-fold more potent than the R-enantiomer with respect to inhibition of 5-HT reuptake and inhibition of 5-HT neuronal firing rate. LEXAPRO (escitalopram) is indicated for the treatment of major depressive disorder and generalized anxiety disorder .

Class (Stereo):
CHEMICAL (ACHIRAL)


Conditions:

Sodium oxybate is the sodium salt of gamma-hydroxybutyrate (GHB), an endogenous metabolite of gamma-aminobutyric acid (GABA) a major inhibitory neurotransmitter. Evidence suggests a role for GHB as a neuromodulator/neurotransmitter. Under endogenous conditions and concentrations, and depending on the cell group affected, GHB may increase or decrease neuronal activity by inhibiting the release of neurotransmitters that are co-localised with GHB. After exogenous administration, most of the observed behavioural effects appear to be mediated via the activity of GHB at GABA(B) receptors, as long as the concentration is sufficient to elicit binding, which does not happen at endogenous concentrations. Xyrem (sodium oxybate) oral solution is indicated for the treatment of cataplexy in narcolepsy and excessive daytime sleepiness (EDS) in narcolepsy.
Dutasteride is a synthetic 4-azasteroid compound that is a selective inhibitor of both the type 1 and type 2 isoforms of steroid 5 alpha-reductase (5AR), intracellular enzymes that convert testosterone to 5 alpha-dihydrotestosterone (DHT). Type I 5a-reductase is predominant in the sebaceous glands of most regions of skin, including scalp, and liver. Type I 5a-reductase is responsible for approximately one-third of circulating DHT. The Type II 5a-reductase isozyme is primarily found in prostate, seminal vesicles, epididymides, and hair follicles as well as liver, and is responsible for two-thirds of circulating DHT. Dutasteride inhibits the conversion of testosterone to 5 alpha-dihydrotestosterone (DHT), which is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5 alpha-reductase, which exists as 2 isoforms, type 1 and type 2. Dutasteride is a competitive and specific inhibitor of both type 1 and type 2 5 alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Used for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate gland to improve symptoms, and reduce the risk of acute urinary retention and the need for surgery. Marketed under the brand name Avodart.
Imatinib (GLEEVEC®) is a tyrosine kinase inhibitor and antineoplastic agent that inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in chronic myeloid leukaemia (CML). It inhibits proliferation and induces apoptosis in BCR-ABL positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive CML. Imatinib (GLEEVEC®) inhibits colony formation in assays using ex vivo peripheral blood and bone marrow samples from CML patients. It is also an inhibitor of the receptor tyrosine kinases for platelet-derived growth factor (PDGF) and stem cell factor (SCF), c-kit, and inhibits PDGF- and SCF-mediated cellular events. In vitro, imatinib (GLEEVEC®) inhibits proliferation and induces apoptosis in gastrointestinal stromal tumor (GIST) cells, which express an activating c-kit mutation.