Mild, transient, asymptomatic elevations in serum aminotransferase levels occur in a small proportion of patients receiving octreotide, and in some individuals the elevations are persistent and worsen over time and may require drug discontinuation. In addition, several instances of acute, clinically apparent liver injury attributable to octreotide have been described. The onset is generally within 1 to 6 months of starting therapy and injury may be more frequent with higher doses. Most cases of liver injury associated with octreotide therapy have been asymptomatic and anicteric, and marked by prominent elevations in serum ALT and AST with normal or near normal serum alkaline phosphatase, GGT and bilirubin. In some instances, however, jaundice has arisen, particularly with rechallenge. There have been no instances of acute liver failure or vanishing bile duct syndrome associated with octreotide, and a characteristic feature of the injury is the rapidity of improvement upon stopping the injections or infusions. Several instances of marked aminotransferase elevations with rapid improvements on stopping have been reported in newborns and infants with congenital hyperinsulinemia who were treated with continuous infusions of high doses of octreotide.
Octreotide causes inhibition of gall bladder contractility and decrease in bile secretion, and long term therapy is associated with a high rate of cholesterol gallstone formation. In prospective studies, between 25% and 65% of patients with acromegaly treated with maintenance octreotide developed gallstones detected by ultrasonography and a proportion developed symptomatic cholelithiasis requiring hospitalization and cholecystectomy. Even after cholecystectomy, cholesterol stones may form in the common bile duct and intrahepatic ducts causing symptoms, episodes of sepsis and need for partial hepatic resection. Therapy with ursodiol does not appear to prevent gallstone formation during octreotide therapy, although it may help. Octreotide has also been associated with acute pancreatitis, which may be due to its inhibitory effect on gastrointestinal hormone release, although other cases may be secondary to passage of gall bladder stones and pancreatic duct obstruction.
Likelihood score: C (probable cause of clinically apparent liver injury).
◉ Summary of Use during Lactation:The excretion of octreotide into breastmilk has not been studied. However, because it has a high molecular weight of 1019 daltons it is likely to be poorly excreted into breastmilk. It is poorly absorbed orally and has been safely administered directly to infants by injection, so it is unlikely to adversely affect the breastfed infant. At least 3 infants have been successfully breastfed with no adverse effects reported. Until more data are available, octreotide should be used in nursing mothers with careful infant monitoring, especially if the infant is under 2 months of age.
◉ Effects in Breastfed Infants:One mother was treated for acromegaly during pregnancy and postpartum with octreotide (dose not stated). She breastfed (extent not stated) her infant for 4 months with no apparent problems noted in the infant.
A woman with acromegaly took long-acting octreotide (Sandostatin LAR; dose not stated) every 6 weeks postpartum while breastfeeding. At 6 months postpartum, the frequency of the injections was increased to every 4 weeks. She breastfed her infant (extent not stated) for 12 months. At age 5 years the child had developed normally.
◉ Effects on Lactation and Breastmilk:A pregnant woman with acromegaly started long-acting octreotide 10 mg monthly at 12 weeks gestation. After delivery, she breastfed her until 6 weeks postpartum when she required an increase in octreotide LAR to 20 mg monthly. She continued to breastfeed successfully on octreotide.
来源:Drugs and Lactation Database (LactMed)
毒理性
蛋白质结合
大约65%的剂量在血浆中与脂蛋白和清蛋白结合。
Approximately 65% of the dose is bound in the plasma to lipoproteins and albumin.
After a subcutaneous dose, octreotide is absorbed completely upon administration. After the administration of an oral delayed-release capsule, peak concentrations were found to be 33% lower than after subcutaneous administration. The Cmax was attained at 1.67–2.5 hours after oral administration versus 30 minutes for the subcutaneous route. At 20 mg twice a day in patients with acromegaly, peak concentration was 2.5 mg/nL versus 5.30 ng/mL at 40 mg twice a day. AUC increases in proportion with the dose, regardless of the route.
About 32% of an oral octreotide dose is excreted into the urine and 30-40% is excreted by the liver into the feces.. About 11% of the unchanged parent drug is found in the urine, and 2% of the unchanged parent drug can be recovered in the feces.
In a pharmacokinetic study, the volume of distribution was 13.6 L in healthy volunteers. One pharmacokinetic study revealed a volume of distribution ranging from 18.1-30.4L after intravenous administration in healthy volunteers.
来源:DrugBank
吸收、分配和排泄
清除
奥曲肽的总体清除率为7-10 L/h。一项药代动力学研究显示总体清除率为11.4 L/h。
The total body clearance of octreotide is 7-10 L/h. One pharmacokinetic study revealed a total body clearance of 11.4 L/h.
glycosides possessing strong antitumor activity in vitro have still not passed phase I clinical trials, mostly due to poor tumor selectivity and systemic toxicity. To overcome this drawback, we designed octreotide-periplogenin (OCT-PPG) conjugate by coupling PPG-succinate to the amino-terminal end of octreotide. In comparison with free PPG, the conjugate exhibited significantly stronger cytotoxicity on
improved efficiency. N-Phenyl-N-aceto-vinylsulfonamide exhibits higher reactivity and has emerged as an efficient reagent that has the ability to realize the selective modification of peptides and proteins at the N-terminus via aza-Michael addition. We showed that, after conjugation of peptides and proteins with the reagent containing a bioorthogonal functional group, the derivatives could be further
合成并筛选了许多乙烯基磺酰胺,以鉴定可用于在生物 pH 值和室温下以更高的效率修饰奥曲肽的试剂。N-Phenyl-N-aceto-vinylsulfonamide 表现出更高的反应性,并已成为一种有效的试剂,能够通过 aza-Michael 加成在 N 端实现肽和蛋白质的选择性修饰。我们表明,在肽和蛋白质与含有生物正交官能团的试剂缀合后,衍生物可以通过功能进一步标记,包括荧光标签、修饰药物和聚乙二醇 (PEG) 聚合物,而无需事先处理。生长抑素、溶菌酶和 RNaseA 在 N 端进行了选择性修饰,说明了该方法的应用。
Process for the formation of disulfide bonds in cyclic peptides
申请人:Cappelletti Silvana
公开号:US20050239695A1
公开(公告)日:2005-10-27
A non-oxidative process is described for the formation of an intramolecular disulfide bond in precursors of the peptide or peptidomimetic type; said process comprises the preparation of a linear intermediate containing an —SH group in the S-sulfonate form and a second —SH group which is obtainable in the free form by means of acid treatment.