Pharmacokinetics of liposomal amphotericin B during extracorporeal albumin dialysis

Extracorporeal blood purification techniques such as hemofiltration or albumin dialysis can exert a significant, but not easily predictable influence on plasma pharmacokinetics of antimicrobial agents. The effect of albumin dialysis on the pharmacokinetics of liposomal amphotericin B (AMB) and other lipid-formulated drugs has not been investigated so far. Therefore, plasma concentrations of liberated and liposomal AMB were measured in a patient, who obtained liposomal AMB for suspected invasive mycosis and required albumin dialysis because of cholestatic liver failure caused by graft versus host disease after bone marrow transplantation. Liberated and liposomal AMB were separated by solid phase extraction and measured by high performance liquid chromatography. No excessive AMB elimination took place during albumin dialysis. Plasma levels of liposomal AMB exceeded those of liberated AMB. Pharmacokinetic data were comparable to those obtained previously in patients on hemofiltration and in critically ill patients without extracorporeal blood purification.     

Renal effects of amphotericin B lipid complex

A study was conducted to compare the renal effects of amphotericin B lipid complex (ABLC), a lipid formulation of the widely used antifungal medication, with conventional amphotericin B (AmB) in the treatment of serious fungal infections, including invasive candidiasis, cryptococcal meningitis, and aspergillosis. The clinical experience of ABLC includes two types of open-label studies: randomized comparative (ABLC 5 mg/kg/d compared with AmB 0.6 to 1 mg/kg) and emergency use. In the comparative studies, changes in serum creatinine were evaluated three ways: doubling of the baseline value, an increase from < or = 1.5 mg/dL at baseline to > or = 1.5 mg/dL, and an increase from < or = 1.5 mg/dL at baseline to > or = 2.0 mg/dL. More patients in the AmB group reached these end points than in the ABLC group (P < or = 0.007), and the time needed to reach each of these end points was significantly shorter for the AmB group (P < or = 0.02). Increased serum creatinine was reported as an adverse event more frequently by patients receiving AmB than by patients receiving ABLC. In the emergency use study, a steady and statistically significant decrease in serum creatinine was observed among patients who started ABLC treatment with serum creatinine greater than 2.5 mg/dL due to prior AmB treatment. ABLC offers the physician a valuable, less-nephrotoxic alternative to AmB for the treatment of patients with severe, invasive fungal infections.     

Comparative safety of amphotericin B lipid complex and amphotericin B deoxycholate as aerosolized antifungal prophylaxis in lung-transplant recipients

BACKGROUND: Aerosolized administrations of amphotericin B deoxycholate (AmBd) and amphotericin B lipid complex (ABLC) in lung transplant recipients were compared for safety and tolerability. The incidence of invasive fungal infections in patients receiving aerosolized amphotericin B formulations as sole prophylaxis was determined. METHODS: A prospective, randomized (1:1), double-blinded trial was conducted with 100 subjects. AmBd and ABLC were administered postoperatively by nebulizer at doses of 25 mg and 50 mg, respectively, which were doubled in mechanically ventilated patients. The planned treatment was once every day for 4 days, then once per week for 7 weeks. Treatment-related adverse events and invasive fungal infections were quantitated for 2 months after study drug initiation. RESULTS: Intent-to-treat analysis revealed study drug was discontinued for intolerance in 6 of 49 (12.2%) and 3 of 51 (5.9%) patients in the AmBd- and ABLC-treated groups, respectively (p=0.313). Subjects receiving AmBd were more likely to have experienced an adverse event (odds ratio 2.16, 95% confidence interval 1.10, 4.24, p=0.02). Primary prophylaxis failure within 2 months of study drug initiation was observed in 7 of 49 (14.3%) AmBd-treated patients and 6 of 51 (11.8%) ABLC-treated patients. No fungal pneumonias were observed. Only two (2%) patients experienced documented primary prophylaxis failure with Aspergillus infections within the follow-up period. CONCLUSIONS: Both aerosol AmBd and ABLC appear to be associated with a low rate of invasive pulmonary fungal infection in the early posttransplant period. Patients receiving ABLC were less likely to experience a treatment-related adverse event.     

Safety of aerosolized amphotericin B lipid complex in lung transplant recipients

BACKGROUND: Fungal infections remain an important cause of morbidity and mortality in lung transplant recipients. Aerosolized amphotericin B lipid complex (ABLC) may be more efficacious than conventional amphotericin B in the prevention of fungal infections in animal models, but experience with aerosolized ABLC in humans is lacking. METHODS: We conducted a prospective, noncomparative study designed to evaluate safety of aerosolized ABLC in lung or heart-lung transplant recipients. RESULTS: A total of 381 treatments were administered to 51 patients. Complete spirometry records were available for 335 treatments (69 in intubated patients, 266 in extubated patients). ABLC was subjectively well tolerated in 98% of patients. Pulmonary mechanics worsened by 20% or more posttreatment in less than 5% of all treatments. There were no significant adverse events related to study medication in any patient, and 1-year survival for all enrolled patients was 78%. CONCLUSION: Administration of nebulized ABLC is safe in the short-term and well-tolerated in lung transplant recipients. Additional prospective, randomized studies are needed to determine the efficacy of aerosolized ABLC alone or in conjunction with systemic therapies in the prevention of fungal infections in lung transplant recipients.     

Effect of amphotericin B lipid complex (ABLC) in very low birth weight infants

The aim of this retrospective, case-control study was to determine the effect of the amphotericin B lipid complex (ABLC) on serum creatinine (SCr), blood urea nitrogen (BUN), sodium (Na), and potassium (K) in very low birth weight (VLBW) infants. Medical records of all VLBW infants who were admitted to our Neonatal Intensive Care Unit between May 1998 and May 2006 and had received ABLC for at least 2 weeks were reviewed for patient demographics, use of medications (ABLC, diuretics, xanthines, indomethacin, vancomycin, gentamicin, pressors, and inotropes), fluid intake, urinary output, and serum electrolytes. Thirty-five patients who received ABLC were identified and matched by gestational age (GA) to 35 patients who served as controls. Infants who received ABLC had an average GA of 25.7 +/- 2.1 weeks and a birth weight of 764 +/- 196 g. Between day 1 and 14 of ABLC treatment, the BUN decreased from 17.5 +/- 11.5 to 10.5 +/- 6.8 mg/dl (p = 0.01), the SCr varied between 0.78 +/- 0.32 and 0.69 +/- 0.32 mg/dl, Na varied between 136.6 +/- 5.8 and 137.8 +/- 3.6 mEq/l, and K varied between 4.8 +/- 0.9 and 4.9 +/- 0.6 mEq/l, respectively. Based on these results, we conclude that treatment with ABLC for 2 weeks did not increase BUN or SCr, nor decrease Na or K in VLBW infants.     

Comparison of the effect of amphotericin B desoxycholate and amphotericin B colloidal dispersion on renal functions and renal morphology in rats

BACKGROUND AND AIM: Amphotericin B (AmB) desoxycholate remains as one of the most efficacious agents currently available for the treatment of systemic fungal infections; however, amphotericin B colloidal dispersion (ABCD) has been developed because of AmB desoxycholate nephrotoxicity. The goal of our study was to compare the effect of administration of AmB desoxycholate and ABCD on renal functions and renal morphology in rats. RESULTS: Amophotericin B desoxycholate as well as ABCD causes damage to renal tubuli and polyuria. Amophotericin desoxycholate causes considerably more severe damage to tubuli than ABCD, but the morphological damage to renal glomeruli is minimal in both formulas. In tubular cells, AmB desoxycholate causes severe damage to mitochondria, vacuolation of cytoplasm, and increased values of volume density of peroxisomes. CONCLUSION: None of these formulas causes a decrease in glomerular filtration in rats when animals are properly hydrated.     

Successful outcome of liver transplantation in a patient with hepatitis C and common variable immune deficiency

A 43-year-old man with common variable immune deficiency underwent liver transplantation for cirrhosis caused by hepatitis C virus (HCV). HCV had been acquired from a contaminated batch of immunoglobulin. He developed cirrhosis within 3 years of infection with the virus, then liver failure requiring liver transplantation. The immediate post-transplant course was uncomplicated. Five months after transplantation he developed liver failure, and the histological appearances were those of severe cholestatic hepatitis. Withdrawal of immunosuppression resulted in recovery from liver failure. Clearance of the HCV from serum was also observed and has been sustained during follow-up (despite the subsequent reintroduction of low-dose immunosuppression). The patient is alive and well more than 5 years after transplantation. His post-transplant course has been remarkable for the aggressive recurrence then clearance of the HCV.     

Interferon alpha 2B and ribavirin in severe recurrent cholestatic hepatitis C

Severe recurrent cholestatic hepatitis C after liver transplantation has a poor prognosis and no standard therapy is currently available. Four cases of severe recurrent cholestatic hepatitis C treated with a combination of interferon alpha 2b and ribavirin are described. All four patients were transplanted for hepatitis C-related cirrhosis. The mean age at transplantation was 45 years (range 41-51 years). Three of the patients were male and one was female. All four patients had hepatitis C virus viremia before and after liver transplantation. At 2 to 23 months after liver transplantation, all four patients developed jaundice, cholestatic elevation of liver enzymes, and histopathology consistent with severe recurrent cholestatic hepatitis C. Combination of interferon and ribavirin was given with prompt virological suppression. Despite this rapid viral suppression, all four patients developed progressive graft failure with three deaths.     

Adefovir treatment in posttransplant hepatitis B virus infection resistant to lamivudine plus hepatitis B virus immunoglobulin

Failure of prophylaxis for hepatitis B virus (HBV) recurrence in liver transplant patients with HBV immunoglobulin (HBIG) or lamivudine or both can be associated with rapid development of liver failure. Some of these patients develop a devastating clinicopathological state characterized by jaundice and rapidly progressive liver failure or fibrosing cholestatic hepatitis. We present two liver transplant recipients who experienced HBV recurrence while they were under lamivudine and HBIG prophylaxis. One of them had finding of severe HBV infection; the other, fibrosing cholestatic hepatitis. After commencing adefovir dipivoxil both patients showed improvements in clinical status and laboratory data. At month 4 of treatment, HBV DNA values became negative and liver function tests almost normalized. In addition, in one case showed HBs ag/anti-HBs seroconversion. When failure of prophylaxis with lamivudine and HBIG occurs, adefovir dipivoxil should be considered to be a safe and effective choice for recurrent HBV infections in liver transplant patients.     

Efficacy and safety of Amphotericin B Lipid Complex Injection (ABLC) in solid-organ transplant recipients with invasive fungal infections

Background: Fungal infections following solid-organ transplantation are a major source of morbidity and mortality. This report describes the efficacy and safety of Amphotericin B Lipid Complex Injection (ABLC) in solid-organ transplant recipients.
Methods: Three open-label, second-line treatment studies evaluated ABLC as a treatment for severe, life-threatening mycoses in patients who were refractory to or intolerant to conventional antifungal (mostly amphotericin B [AmB]) therapy or had pre-existing renal disease.
Results: The 79 solid-organ transplant recipients (25 heart, 20 liver, 17 kidney, 11 lung, 5 multiple, 1 pancreas) who received ABLC in these studies had the following fungal infections: aspergillosis (n=39); candidiasis (n=20); zygomycosis (n=8); cryptococcosis and histoplasmosis (n=3 each); and blastomycosis, cladosporiosis, fusariosis, Bipolaris hawaiiensis , Dactylaria gallopava , and an unspecified fungal infection (n=1 each). The median duration of ABLC therapy was 28 d (1–178 d). The daily dose ranged between 1.6 and 7.4 mg/kg (median, 4.6 mg/kg). The clinical response rate for the patients who could be assessed was 58% (39/67). Clinical response rates for heart, liver, kidney, and lung recipients were 59, 60, 67, and 40%, respectively; response rates for aspergillosis and candidiasis were 47 and 71%, respectively. Forty-six of the 79 patients (58%) survived for more than 28 d after the last dose of ABLC. Mean baseline serum creatinine was 3.2 mg/dL; 64 patients (81%) had stable (n=37) or improved (n=27) serum creatinine at the end of treatment.
Conclusions: ABLC is safe and effective treatment for fungal infections in solid-organ transplant recipients. Its renal-sparing properties are particularly suited for this high-risk population for renal failure.     

Intravenous interferon during the anhepatic phase of liver retransplantation and prevention of recurrence of cholestatic hepatitis C virus.

Cholestatic hepatitis C virus (HCV) infection post orthotopic liver transplantation is associated with a poor prognosis. We describe 2 patients who received interferon and ribavirin for cholestatic HCV infection with clearance of HCV RNA from the serum. Both developed signs of graft failure necessitating repeat orthotopic liver transplantation, and at surgery, interferon was administered during the anhepatic phase to prevent graft reinfection. Both patients are doing well with no evidence of recurrent viremia at 36 and 24 months of follow-up after repeat transplantation, respectively. Our results suggest that in those with cholestatic HCV infection, repeat transplantation after viral clearance is feasible and can occur without reinfection of the graft, challenging the current practice of denying retransplantation for patients with cholestatic HCV. The role of anhepatic administration of interferon deserves further examination, and this combination may provide a solution in a subset of patients with an otherwise poor prognosis.     

Spontaneous Clearance of Hepatitis C Virus Infection Post–Liver Transplantation Is Associated With Rapidly Changing Quasispecies: A Single Case Report

Hepatitis C virus (HCV) clearance post–liver transplantation is uncommon. This is a case report of a patient who, after liver transplantation, developed cholestatic hepatitis characterized by severe graft dysfunction, in conjunction with high viral load. This was, however, followed by viral clearance and normalization of allograft function. The clinical features of this case and the quasispecies patterns during the illness and the clearance periods are described. In addition, management implications in terms of immunosuppressive therapy are discussed. (Liver Transpl 2000;6:648-653.)     

Acidifying defect induced by amphotericin B: comparison of bicarbonate and hydrogen ion permeabilities.

The defect in urinary acidification induced by amphotericin B (AMB) was further characterized in turtle bladder. Since AMB has been shown to increase the hydrogen ion (H+) permeability of this epithelium in the absence of exogenous bicarbonate ions (HCO3-), we explored the permeability characteristics in the presence of imposed bicarbonate ion gradients, comparable to those occurring in vivo. With mucosal (M) pH lowered to the point of zero net hydrogen ion secretion, the transepithelial flow of bicarbonate ions (JHCO3) from serosa (S) to M was 0.91 +/- .06 y mole/hr in response to a 20 mM HCO3- gradient. After AMB addition to M, back diffusion of hydrogen ions from M to S (-JH) increased from zero to 0.36+/-0.05 micronmole/hr, whereas bicarbonate ion transport from S to M (JHCO3) failed to increase (0.91+/-0.06 before and 0.82+/-0.09 micronmole/hr after AMB). In contrast to M addition, S addition of AMB had no effect on either -JH or JHCO3. The defect in urinary acidification induced by AMB is characterized by a large increase in the permeability for hydrogen ions rather than that for bicarbonate ions and depends on direct exposure of the luminal cell membrane to AMB. The permeability increase is cation selective, not only for hydrogen ions but also, as shown previously, for potassium ions, and to a lesser extent, for sodium ions. The results are consistent with the formation by AMB of aqueous half pores in the luminal membrane. Although the passive permeabilities for bicarbonate and chloride ions are not affected primarily, they may increase after prolonged exposure, probably as a results of paracellular leaks that are not specific for AMB.     

Effects of cholestatic hepatic disease and chronic renal failure on alfentanil pharmacokinetics in children

The role of the liver and the kidney in alfentanil metabolism has not been defined. The effects of cholestatic hepatic disease and chronic renal failure on the pharmacokinetics of alfentanil were evaluated in 9 children undergoing liver transplantation and 10 children undergoing kidney transplantation. These findings were compared with data from 10 children with normal hepatic and renal function undergoing other surgical procedures. There was no statistical difference among the 3 groups with respect to apparent volume of distribution, half-life, or clearance. In a subgroup of 3 patients undergoing liver transplantation alfentanil kinetics were determined both before and after the allograft was incorporated into the recipient's circulation. Though both volume of distribution and elimination half-life increased in the posttransplantation period, only the decrease in clearance was statistically significant. Thus, it appears that alfentanil may be a useful anesthetic agent in pediatric patients with cholestatic hepatic disease or chronic renal failure. The dose of alfentanil in these patients need not be altered except in the period immediately after liver transplantation.     

Profound mishandling of protein glycation degradation products in uremia and dialysis

The aim of this study was to define the severe deficits of protein glycation adduct clearance in chronic renal failure and elimination in peritoneal dialysis (PD) and hemodialysis (HD) therapy using a liquid chromatography-triple quadrupole mass spectrometric detection method. Physiologic proteolysis of proteins damaged by glycation, oxidation, and nitration forms protein glycation, oxidation, and nitration free adducts that are released into plasma for urinary excretion. Inefficient elimination of these free adducts in uremia may lead to their accumulation. Patients with mild uremic chronic renal failure had plasma glycation free adduct concentrations increased up to five-fold associated with a decline in renal clearance. In patients with ESRD, plasma glycation free adducts were increased up to 18-fold on PD and up to 40-fold on HD. Glycation free adduct concentrations in peritoneal dialysate increased over 2- to 12-h dwell time, exceeding the plasma levels markedly. Plasma glycation free adducts equilibrated rapidly with dialysate of HD patients, with both plasma and dialysate concentrations decreasing during a 4-h dialysis session. It is concluded that there are severe deficits of protein glycation free adduct clearance in chronic renal failure and in ESRD on PD and HD therapy.     

Effect of chronic theophylline administration on amphotericin B nephrotoxicity in rats

The effect of chronic theophylline administration on amphotericin B nephrotoxicity was investigated in rats. A 7-day treatment of amphotericin B (5 mg/kg/day i.p.) significantly reduced the glomerular filtration rate (GFR) measured as inuline clearance and creatinine clearance (0.74 +/- 0.29 and 0.16 +/- 0.04 ml/min, respectively) in comparison to vehicle-treated rats (2.04 +/- 0.23 and 1.29 +/- 0.19 ml/min, respectively). The reduced GFR led to evaluations in serum creatinine and BUN concentrations (0.94 +/- 0.09 and 78 +/- 11 mg/dl) in comparison to their own values before treatment (0.45 +/- 0.11 and 19 +/- 3 mg/dl). In addition amphotericin B induced an increase in sodium and a decrease in potassium excretion, the fractional sodium excretion was elevated 50-fold. The methylxanthine, theophylline, had a beneficial effect on the outcome of amphotericin-B-induced renal failure. The inuline clearance was 1.17 +/- 0.04 ml/min, the creatinine clearance 0.43 +/- 0.03 ml/min, the serum creatinine concentration 0.76 +/- 0.05 mg/dl and the BUN concentration 40 +/- 6 mg/dl. Theophylline had no effect on total sodium excretion and potassium excretion. The fractional sodium excretion, however, improved significantly. Theophylline as well as sodium deoxycholate, the detergent of amphotericin B, given alone had no effect on renal hemodynamics measured after 7 days.     

Acute cholestatic liver disease protects against glycerol-induced acute renal failure in the rat

BACKGROUND: It is widely held that liver disease predisposes toward acute tubular necrosis. The present study examines the effect of acute cholestatic liver disease on the susceptibility to glycerol-induced acute tubular necrosis in the rat. METHODS: Acute cholestatic liver disease was induced by ligation of the common bile duct, while the intramuscular injection of hypertonic glycerol was used to induce acute tubular necrosis. Renal injury was assessed by plasma creatinine concentration and renal histology. An in vitro model of heme protein-induced renal injury (hemoglobin in conjunction with glutathione depletion) was employed to assess the cytoprotective effects of bilirubin. RESULTS: Ligation of the common bile duct markedly reduced acute renal injury that occurs in the glycerol model (7.5 mL/kg body weight), as evidenced by a lower plasma creatinine concentration and less severe renal histologic injury. At a higher dose of glycerol (10 mL/kg body weight), ligation of the common bile duct again reduced renal injury and cumulative mortality that occurs five days after the induction of this model of acute renal failure. These protective effects of ligation of the common bile duct could not be ascribed to less severe muscle injury or red cell damage. Ligation of the common bile duct induced heme oxygenase-1 in the kidney and markedly so in the liver. Inhibition of heme oxygenase significantly attenuated, but did not prevent, the protective effects conferred by ligation of the common bile duct. Bilirubin, in low micromolar concentrations, was cytoprotective against heme protein-induced cell injury in vitro. CONCLUSIONS: Ligation of the common bile duct confers resistance to glycerol-induced acute tubular necrosis in the rat, actions that arise, in part, from the induction of heme oxygenase-1 in the kidney and liver. Bilirubin, in micromolar concentrations, protects against heme protein-induced renal injury. Our studies uncover a novel form of acquired resistance to renal injury, occurring, unexpectedly, in the setting of acute cholestatic liver disease. We speculate that such potentially cytoprotective alterations may safeguard the kidney against irreversible functional and structural injury in the hepatorenal syndrome.     

Pharmacokinetics of alfentanil in chronic renal failure

The pharmacokinetics of alfentanil were studied during general anesthesia in nine patients with renal failure and in ten patients with normal renal function. All patients received 0.05 mg/kg alfentanil as an intravenous bolus injection. Plasma concentrations were measured at intervals up to 8 hr, using a specific radioimmunoassay technique. Protein binding was measured by equilibrium dialysis. Elimination half-life and plasma clearance were similar in both groups. The volume of distribution at steady state was greater (P less than 0.02) in patients with renal failure (405 +/- 86 ml/kg) than in patients with normal renal function (281 +/- 97 ml/kg). Patients with renal failure had a higher (P less than 0.01) alfentanil plasma free fraction (0.19 +/- 0.06) than patients with normal renal function (0.11 +/- 0.03). When kinetic parameters were corrected for protein binding, the unbound volume of distribution and the free drug clearance were unchanged in patients with renal failure. These results suggest that the modification of alfentanil free fraction in renal failure does not induce any change in elimination but may influence the distribution of alfentanil.     

Selective bilirubin removal by plasma treatment with Plasorba BR-350 for early cholestatic graft dysfunction

Early cholestatic graft dysfunction is a frequent cause of morbidity after orthotopic liver transplantation (OLT). We analyze the role of selective bilirubin plasma absorption (PAP) using Plasorba BR-350 in 4 OLT patients who had experienced early severe cholestatic graft dysfunction within 15 days after transplantation. Patients were treated with 3 consecutive cycles of PAP with Plasorba BR-350. The median amount of plasma treated was 7500 mL. Median treatment duration was 231 minutes. The average plasma bilirubin level was 37 +/- 1 mg/dL before PAP and decreased to 15 +/- 0.2 mg/dL at the end of the third cycle of PAP; 3 of 4 cases had progressive bilirubin normalization after PAP. The average amount of bilirubin removed from the plasma of the patients during each PAP treatment was 143 +/- 24 mg. At the beginning of each cycle of PAP, the Plasorba BR-350 was able to remove >90% of the total plasma bilirubin, a percentage that decreased to 60%, 50%, and 40% after 2 L, 4 L, and 7 L of plasma were treated, respectively. Liver biopsies performed after the third treatment showed reduced cholestasis when compared with the pretreatment biopsy specimen. The preliminary data suggested that PAP selective for bilirubin removal may not only reduce the bilirubin level, but may also improve the histological pattern of the graft in terms of reduced cholestatic signs.     

Successful treatment of fibrosing cholestatic hepatitis with pegylated interferon,ribavirin and sofosbuvir after a combined kidney–liver transplantation

Fibrosing cholestatic hepatitis (FCH) is a classical but rare and severe form of recurrent hepatitis C virus (HCV) after liver transplantation. Classical anti‐HCV therapy, that is pegylated‐interferon (peg‐interferon) and ribavirin, has been shown to have limited efficacy in treating FCH. Herein, we report on the first case of successful use of peg‐interferon, ribavirin, plus sofosbuvir to treat HCV‐induced FCH in a combined liver–kidney transplant patient. Antiviral therapy was given for 24 weeks. HCV clearance occurred within 4 weeks after starting therapy and was maintained until 4 weeks after the end of therapy. Antiviral tolerance was good. We conclude that the use of sofosbuvir‐based anti‐HCV therapy can be successfully used to treat FCH after a liver or combined kidney–liver transplantation.