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/
... Following a 1 hr IV infusion of 70 mg of (3)HCaspofungin acetate to healthy subjects, excretion of drug-related material was very slow, such that 41 and 35% of the dosed radioactivity was recovered in urine and feces, respectively, over 27 days. Plasma and urine samples collected around 24 hr postdose contained predominantly unchanged caspofungin acetate, together with trace amounts of a peptide hydrolysis product, M0, a linear peptide. However, at later sampling times, M0 proved to be the major circulating component, whereas corresponding urine specimens contained mainly the hydrolytic metabolites M1 and M2, together with M0 and unchanged MK-0991, whose cumulative urinary excretion over the first 16 days postdose represented 13, 71, 1, and 9%, respectively, of the urinary radioactivity. The major metabolite, M2, was highly polar and extremely unstable under acidic conditions when it was converted to a less polar product identified as N-acetyl-4(S)-hydroxy-4-(4-hydroxyphenyl)-L-threonine gamma-lactone. Derivatization of M2 in aqueous media led to its identification as the corresponding gamma-hydroxy acid, N-acetyl-4(S)-hydroxy-4-(4-hydroxyphenyl)-L-threonine. Metabolite M1, which was extremely polar, eluting from HPLC column just after the void volume, was identified by chemical derivatization as des-acetyl-M2. Thus, the major urinary and plasma metabolites of MK-0991 resulted from peptide hydrolysis and/or N-acetylation. /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.
与诱导剂或药物清除的混合诱导剂/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）联合使用卡泊芬净可能会导致卡泊芬净血药浓度显著降低。
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.
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.
