英文药名: Procytox (cyclophosphamide tablets) 中文药名: 环磷酰胺片 药品名称 中文别名:环磷氮芥,安道生,癌得星,癌得散。 CTX为HN2的衍生物,其作用与HN2类似,但抗瘤谱比HN2广,毒性亦比HN2小,亦为细胞周期非特异性药物,但对G2期作用显著。本品在体外无活性,在体内经肝微烂漫混合功能氧化酶P450活化后方具有烷化活力。首先是其环N原子邻近的C被氧化,生成4-羟基环烯磷酰胺,自发开环生成醛磷酰胺(aldophosphoramide),4-羟基环磷酰胺与醛磷酰胺两者维持动态平衡,经可溶性酶分别氧化成4-酮基环磷酰胺和羧基磷酰胺,后两者无细胞毒作用,是从尿中排泄的失活性产物,约占CTX用量的80%。未经氧化的醛磷酰胺可自发生成丙烯醋和磷酰胺氮芥(PM),PM是CTX的活性代谢物,具有烷化活性和细胞毒作用。4-羟基环磷酰胺和醛磷酰胺不具有烷化活性,是一种转运型化合物,将高度极性的PM转运到细胞内和血液循环中,PM和DNA形成交叉联结,影响DNA功能,抑制肿瘤细胞生长与繁殖。CTX在临床上的耐药机制正在研究中,许多学者认为与多药耐药基因及P糖蛋白有关。 本品口服后易被吸收,迅速分布全身,生物利用度为74%~97%,血液浓度1小时后达高峰,与血浆蛋白结合不足20%。在肝脏转化释放出磷酰胺氮芥,半衰期为4~6.5小时;48小时内由肾脏排出50%~70%,68%为代谢物,32%为原形。静脉给药60mg/kg后,血浆峰浓度500umol/L,血浆半衰期为3~10小时。环磷酰胺能少量通过血脑屏障,脑脊液中的浓度仅为血浆的20%。 本品为目前广泛应用的烷化剂之一。 成人: (1)骨髓抑制:以白细胞下降为最常见,在用药后的8~15日达到最低点,但恢复较快,一般在用药后18~25日即可恢复正常;血小板减少不常出现。 (1)孕妇及哺乳妇女禁用。 (1)使用本品采用大剂量冲击或中等剂量间歇给药比小剂量连续给药疗效好。 片剂:25mg/片,50mg/片。 Cyclophosphamide review |
Cyclophosphamide is marketed under the brand name Cytoxan. It is available in tablet form as well as a powder used for intravenous injection. It is prescribed to individuals who are suffering from certain types of cancer such as ovarian, breast, and leukemia. It is also known to cure nephritic syndrome, an ailment of the kidneys among children.
The initial dosage of Cyclophosphamide is at least 40 mg injected in a stretch of 3-5 days divided in various doses. The usual dosage for oral use is 1-5 mg/kg per day. The dosage is then adjusted depending on the tumor’s response to the medication and its side effects.
Cyclophosphamide should be taken as prescribed by a physician. While using Cyclophosphamide, patients should drink more water and urinate more frequently. This should help the kidneys in removing the drug from the system and lowering the chances of occurrence of side effects.
Patients should not stop using Cyclophosphamide until the prescribed schedule of a physician, or even if they experience nausea or vomiting.
This drug usually works a month or two before producing positive results. The effects also hinge on the illness being treated.
One of the most common side effects is nausea. Doctors usually prescribe another medication to reduce this side effect.
Users may also experience bleeding and inflammation of the bladder wall, or haemorrhagic cystitis characterized by blood in the urine. To reduce the chances of this side effect, patients are advised to drink more water, preferably up to 10 glasses a day.
This drug can also have an effect on the blood count of the patient. It can also result to hair loss, irregular menstrual periods, and mouth ulcers. In case a patient develops these symptoms after using Cyclophosphamide, he or she should immediately inform a doctor.
Patients who came into close contact with a person with chicken pox are advised to stop using Cyclophosphamide and immediately consult a doctor. This case usually requires a special, antiviral treatment since chicken pox can be severe among people who are undergoing treatment with Cyclophosphamide.
Since Cyclophosphamide may affect the bladder and the blood, doctors may have to arrange for a blood and urine examination before allowing the patient to start treatment with Cyclophosphamide. Regular examinations are also required while the patient takes Cyclophosphamide. Patients should not take Cyclophosphamide unless they are undergoing regular blood and urine examinations.
Certain medications may interact negatively with other drugs. Patients should make it a point to inform their physicians if they are beginning to take new drugs while taking Cyclophosphamide.
Taking Cyclophosphamide may lead to a decrease in fertility among women and men; so young users are advised to use this medication with caution.
Pregnant women should never take this drug. Cyclophosphamide may also be passed on to infants so breastfeeding mothers should not take this medication.
Cyclophosphamide has the following structural formula:
• Chemical IUPAC Name is 2-[bis(2-chloroethyl)amino] tetrahydro-2H-13,2- oxazaphosphorine 2-oxide monohydrate
• Molecular weight is 279.1 g/mol
• Cyclophosphamide available : 25mg tablets, 50mg tablets
Brand name(s): Clafen, Claphene, Cyclophosphamid, Cyclophosphamidum, Cyclophosphan, Cyclophosphane, Cyclophosphoramide, Cyclostin, Cyklofosfamid, Cytophosphan, Cytoxan, Endoxan, Endoxan R, Endoxana, Endoxanal, Endoxane, Enduxan, Genoxal, Hexadrin, Lyophilized Cytoxan, Mitoxan, Neosar, Procytox, Semdoxan, Sendoxan, Senduxan, Zyklophosphamid