Slowly metabolized by hydrolysis and N-acetylation; also undergoes spontaneous chemical degradation and further hydrolysis to constitutive amino acids and their degredates, including dihydroxyhomotyrosine and N-acetyl-dihydroxyhomotyrosine.
Caspofungin is slowly metabolized in the liver via hydrolysis and N-acetylation; 35 and 41% of the parent drug and metabolites were excreted in feces and urine, respectively, following a single IV radiolabeled dose.
The metabolism, excretion, and pharmacokinetics of caspofungin were investigated after administration of a single intravenous dose to mice, rats, rabbits, and monkeys. ... Excretion of radioactivity in all species studied was slow, and low levels of radioactivity were detected in daily urine and fecal samples throughout a prolonged collection period. Although urinary profiles indicated the presence of several metabolites (M0, M1, M2, M3, M4, M5, and M6), the majority of the total radioactivity was associated with the polar metabolites M1 [4(S)-hydroxy-4-(4-hydroxyphenyl)-L-threonine] and M2 (N-acetyl-4(S)-hydroxy-4-(4-hydroxyphenyl)-L-threonine). Caspofungin was thus primarily eliminated by metabolic transformation; however, the rate of metabolism was slow. ...
Caspofungin is slowly metabolized by hydrolysis and N-acetylation. Caspofungin also undergoes spontaneous chemical degradation to an open-ring peptide compound, L-747969. At later time points (> or = 5 days postdose), there is a low level (< or = 7 picomoles/mg protein, or < or = 1.3% of administered dose) of covalent binding of radiolabel in plasma following single-dose administration of (3)H caspofungin acetate, which may be due to two reactive intermediates formed during the chemical degradation of caspofungin to L-747969. Additional metabolism involves hydrolysis into constitutive amino acids and their degradates, including dihydroxyhomotyrosine and N-acetyl-dihydroxyhomotyrosine. These two tyrosine derivatives are found only in urine, suggesting rapid clearance of these derivatives by the kidneys. /Caspofungin acetate/
◉ Summary of Use during Lactation:No information is available on the use of caspofungin during breastfeeding. Because caspofungin is 97% bound to plasma proteins and has poor oral bioavailability, it is unlikely to reach the milk and be absorbed by the infant. Caspofungin can safely be given intravenously to infants of aged 3 months or older. Any amount absorbed from milk is likely to be far less than an infant dose. If caspofungin is required by the mother, it is not a reason to discontinue breastfeeding.
◉ Effects in Breastfed Infants:Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk:Relevant published information was not found as of the revision date.
... In this study the efficacies of caspofungin and meropenem - separately and together - in mice with disseminated candidiasis were studied. Immunocompetent mice were infected intravenously with 2x10(6) CFU of Candida albicans. At 24 hr postinfection, intraperitoneal therapy was initiated and was continued for 7 days. Therapy groups included those given caspofungin (0.5, 1.25, 5 mg/kg/day), meropenem (20 mg/kg/day), and a combination of the two drugs. ... Kidney CFU counts showed that mice that had received both drugs had lower residual burdens. Caspofungin was effective at doses of 0.5, 1.25, 5 mg/kg compared to infected untreated controls. In vitro, MICs of caspofungin and meropenem were <0.075 ug/mL and >64 ug/mL, respectively. Synergism was observed with the combination. Histopathology showed that the degree of inflammation was 25% less and tubular necrosis was more restricted in combined therapy than monotherapy. The results indicate that concurrent caspofungin and meropenem therapy may be beneficial.
Concomitant use /with tacrolimus/ may result in decreased tacrolimus blood concentrations; monitoring of tacrolimus concentrations is recommended, and dosage adjustments may be required.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
相互作用
Potential pharmacokinetic interaction (reduction in caspofungin plasma concentrations.).
可能存在药代动力学相互作用(降低卡泊芬净血药浓度)。
Coadministration of caspofungin with inducers or mixed inducer/inhibitors of drug clearance such as efavirenz, nelfinavir, nevirapine, phenytoin, rifampin, dexamethasone, or carbamazepine may result in clinically important reductions in plasma caspofungin concentrations.
与诱导剂或混合诱导剂/抑制剂(如依非韦伦、奈非那韦、奈韦拉平、苯妥英、利福平、地塞米松或卡马西平)共同给药可能导致卡泊芬净血药浓度出现具有重要临床意义的降低。
Potential pharmacokinetic interaction (reduction in caspofungin plasma concentrations.). Coadministration of caspofungin with inducers or mixed inducer/inhibitors of drug clearance such as efavirenz, nelfinavir, nevirapine, phenytoin, rifampin, dexamethasone, or carbamazepine may result in clinically important reductions in plasma caspofungin concentrations. ...
The potential for interactions between caspofungin and nelfinavir or rifampin was evaluated in two parallel-panel studies. In study A, healthy subjects received a 14-day course of caspofungin alone (50 mg administered intravenously [IV] once daily) (n = 10) or with nelfinavir (1,250 mg administered orally twice daily) (n = 9) or rifampin (600 mg administered orally once daily) (n = 10). In study B, 14 subjects received a 28-day course of rifampin (600 mg administered orally once daily), with caspofungin (50 mg administered IV once daily) coadministered on the last 14 days, and 12 subjects received a 14-day course of caspofungin alone (50 mg administered IV once daily). The coadministration/administration alone geometric mean ratio for the caspofungin area under the time-concentration profile calculated for the 24-hr period following dosing [AUC(0-24)] was as follows (values in parentheses are 90% confidence intervals [CIs]): 1.08 (0.93-1.26) for nelfinavir, 1.12 (0.97-1.30) for rifampin (study A), and 1.01 (0.91-1.11) for rifampin (study B). The shape of the caspofungin plasma profile was altered by rifampin, resulting in a 14 to 31% reduction in the trough concentration at 24 hr after dosing (C(24h)), consistent with a net induction effect at steady state. Both the AUC and the C(24hr) were elevated in the initial days of rifampin coadministration in study A (61 and 170% elevations, respectively, on day 1) but not in study B, consistent with transient net inhibition prior to full induction. The coadministration/administration alone geometric mean ratio for the rifampin AUC(0-24) on day 14 was 1.07 (90% CI, 0.83-1.38). Nelfinavir does not meaningfully alter caspofungin pharmacokinetics. Rifampin both inhibits and induces caspofungin disposition, resulting in a reduced C(24hr) at steady state. An increase in the caspofungin dose to 70 mg, administered daily, should be considered when the drug is coadministered with rifampin.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
吸收
36-48小时内静脉输注后92%的组织分布
92% tissue distribution within 36-48 hours after intravenous infusion
After single intravenous administration of [3H] caspofungin acetate, excretion of caspofungin and its metabolites in humans was 35% of dose in feces and 41% of dose in urine.
Elimination: Fecal: 35% as drug or metabolites. Renal: 41% as drug (approximately 1.4% unchanged) or metabolites. In dialysis: Not removed by hemodialysis.
Following administration of a single 70 mg irradiated dose, approximately 92% of the administered radioactivity was distributed into tissues within 36 to 48 hours. Distribution into red blood cells in minimal.
(1,3)- D -葡聚糖合成酶是真菌细胞壁合成的关键成分。卡泊芬净通过非竞争性抑制该酶发挥抗真菌作用。静脉给药后,药物在组织中的分布迅速导致血浆药物浓度下降,随后逐渐从组织中释放。随着剂量的增加,药物代谢也会增加,并且多次给药达到稳态的时间也具有剂量相关性。因此,在临床应用中需注意调整剂量,以避免不良反应。