The Increasing Prognostic and Predictive Roles of the Tumor Primary Chemosensitivity Assessed by CA-125 Elimination Rate Constant K (KELIM) in Ovarian Cancer: A Narrative Review

Ovarian cancer is the gynecological cancer with the worst prognosis and the highest mortality rate because 75% of patients are diagnosed with advanced stage III–IV disease. About 50% of patients are now treated with neoadjuvant chemotherapy followed by interval debulking surgery (IDS). In that context, there is a need for accurate predictors of tumor primary chemosensitivity, as it may impact the feasibility of subsequent IDS. Across seven studies with more than 12,000 patients, including six large randomized clinical trials and a national cancer registry, along with a mega-analysis database with 5842 patients, the modeled CA-125 ELIMination rate constant K (KELIM), the calculation of which is based on the longitudinal kinetics during the first three cycles of platinum-based chemotherapy, was shown to be a reproducible indicator of tumor intrinsic chemosensitivity. Indeed, KELIM is strongly associated with the likelihood of complete IDS, subsequent platinum-free interval, progression-free survival, and overall survival, along with the efficacy of maintenance treatment with bevacizumab or veliparib. As a consequence, KELIM might be used to guide more subtly the medical and surgical treatments in a first-line setting. Moreover, it could be used to identify the patients with poorly chemosensitive disease, who will be the best candidates for innovative treatments meant to reverse the chemoresistance, such as cell cycle inhibitors or immunotherapy.

Comparison of Vancomycin Pharmacokinetics in Cystic Fibrosis Patients Pre and Post-lung Transplant

Background: Vancomycin is commonly used to treat acute cystic fibrosis (CF) exacerbations associated with methicillin-resistant Staphylococcus aureus (MRSA). Multiple studies have demonstrated pharmacokinetic differences of antimicrobials in the CF population. Very little data exist regarding pharmacokinetics postlung transplant, but 2 studies have noted changes in tobramycin pharmacokinetics. No such studies exist evaluating vancomycin in CF patients postlung transplant. Methods: A retrospective cohort review of CF patients who underwent lung transplantation and received vancomycin pre- and posttransplant was conducted. CF patients who underwent transplant between 2007 and 2016 at 4 medical centers throughout the United States were included. The primary endpoint was the change in elimination rate constant. The secondary endpoints were subgroup analyses of patients grouped by age, time posttransplant, and number of nephrotoxic medications. Results: A total of 25 patients were included, of which just under half were pediatric. Patients were significantly older and heavier posttransplant and had higher serum creatinine and number of nephrotoxic medications. The change in elimination rate constant from pre- to posttransplant was −0.50 hr−1 which was statistically significant ( P < .001). This significant decrease was consistent among all subgroups of patients evaluated with the exception of pediatric patients. Conclusion: Vancomycin pharmacokinetics are significantly altered in CF patients in the posttransplant setting as evidenced by a decrease in elimination rate constant. This decrease may be related to a decrease in renal clearance and higher numbers of nephrotoxic medications posttransplant. Regardless, pretransplant vancomycin regimens may not predict appropriate posttransplant regimens.

Pharmacokinetics of Caspofungin in Critically Ill Patients in Relation to Liver Dysfunction: Differential Impact of Plasma Albumin and Bilirubin Levels

ABSTRACT Caspofungin has a liver-dependent metabolism. Reduction of the dose is recommended based on Child-Pugh (C-P) score. In critically ill patients, drug pharmacokinetics (PK) may be altered. The aim of this study was to investigate the prevalence of abnormal liver function tests, increased C-P scores, their effects on caspofungin PK, and whether pharmacokinetic-pharmacodynamic (PK/PD) targets were attained in patients with suspected candidiasis. Intensive care unit patients receiving caspofungin were prospectively included. PK parameters were determined on days 2, 5, and 10, and their correlations to the individual liver function tests and the C-P score were analyzed. Forty-six patients were included with C-P class A (n = 5), B (n = 40), and C (n = 1). On day 5 (steady state), the median and interquartile range for area under the curve from 0 to 24 h (AUC0–24), clearance (CL), and central volume of distribution (V1) were 57.8 (51.6 to 69.8) mg·h/liter, 0.88 (0.78 to 1.04) liters/h, and 11.9 (9.6 to 13.1) liters, respectively. The C-P score did not correlate with AUC0–24 (r = 0.03; P = 0.84), CL (r = −0.07; P = 0.68), or V1 (r = 0.19; P = 0.26), but there was a bilirubin-driven negative correlation with the elimination rate constant (r = −0.46; P = 0.004). Hypoalbuminemia correlated with low AUC0–24 (r = 0.45; P = 0.005) and was associated with higher clearance (r = −0.31; P = 0.062) and somewhat higher V1 (r = −0.15; P = 0.37), resulting in a negative correlation with the elimination rate constant (r = −0.34; P = 0.042). For Candida strains with minimal inhibitory concentrations of ≥0.064 μg/ml, PK/PD targets were not attained in all patients. The caspofungin dose should not be reduced in critically ill patients in the absence of cirrhosis, and we advise against the use of the C-P score in patients with trauma- or sepsis-induced liver injury.

Effect of fever on pharmacokinetics and disposition in biological fluids of minocycline in goats

Effect of fever on distribution, kinetic parameters and dosage regimen of minocycline in goats was studied. Concentrations of minocycline (5 mg.kg-1, i.v.) in plasma, milk, urine and interstitial fluid (ISF) were estimated in six afebrile and febrile goats by microbiological assay. Fever was induced by i.m. injection of lipopolysccharide of Eschreichia coli @ 0.20 mg.kg-1 i.m. which induced an in temperature of 1. 5 – 2.00F after 1 h of injection which was maintained for 8 h. Three injections of endotoxin were given during the period of study. Minocycline attained its mean peak concentration in milk, urine and interstitial fluid (ISF) earlier in febrile goats (0.75 h) than in afebrile goats (1 h). Kinetic parameters like absorption rate constant (a), elimination rate constant (b), elimination rate constant from central to peripheral compartment (K12), elimination rate constant from peripheral to central constant (K21) and elimination rate constant from central compartment (Kel) were higher in febrile goats as compared to afebrile goats. Dosage regimen in goat, particularly in febrile condition was calculated so that it may be a guideline for physicians to treat the animals. Loading dose and maintenance doses were dependent on â and hence, for maintaining mean therapeutic level of 0.5ìg/ml in plasma, a loading dose (D*) of 6.9 mg/kg and maintenance dose (D0) of 4.7 mg/kg at dosage interval (g) of 12 h may be used in afebrile goats whereas higher doses of D* of 7.8 mg/kg followed by D0 of 6.1 mg/kg at g of 12 h may be administered in febrile goats.

Kinetic simulation method of C-reactive protein in beagle dogs during acute inflammation

The half-life ( t1/2) of C-reactive protein (CRP) and its ability to stimulate weak inflammatory responses were investigated in beagle dogs. Four beagle dogs were administered 20 mg/kg indomethacin and blood was collected from the cephalic vein pre-dosing and at 24, 48, 72, 96, 144, 192, 240, 312, and 360 h post-administration. The serum concentrations of CRP were measured by enzyme-linked immunosorbent assay. The serum t1/2 was calculated using the equation 0.693/elimination rate constant. The serum concentration of CRP beyond 192 h post-administration declined to levels in the normal range. The t1/2 was 148.3 h, which is considered to be the essential t1/2 of CRP. The simulation of CRP serum concentrations at arbitrary times using the elimination rate constant obtained in this study became possible.

Pharmacokinetics of human chorionic gonadotropin after i.m. administration in goats (Capra hircus)

The present investigation addresses the pharmacokinetics of human chorionic gonadotropin (hCG), intramuscularly (i.m.) administered to goats. Nine pluriparous does of the Boer goat breed, 2–6 years of age and weighing 45–60 kg, were administered 500 IU hCG (2 ml Chorulon) deep into the thigh musculature 18 h after superovulatory FSH treatment. Blood samples were drawn from the jugular vein at 2 h intervals for the first 24 h, at 6 h intervals until 42 h, and at 12 h intervals until 114 h after administration. After centrifugation, plasma hCG concentrations were determined by electrochemiluminescence immunoassay. Pharmacokinetical parameters were as follows: lag time, 0.4 (s.e.m. 0.1) h; absorption rate constant, 0.34 (s.e.m. 0.002) h; absorption half-life, 2.7 (s.e.m. 0.5) h; elimination rate constant, 0.02 (s.e.m. 0.002) h; biological half-life, 39.4 (s.e.m. 5.1) h; and apparent volume of distribution, 16.9 (s.e.m. 4.3) l. The plasma hCG profile was characterized by an absorption phase of 11.6 (s.e.m. 1.8) h and an elimination phase of 70.0 (s.e.m. 9.8) h, with considerable individual variation in bioavailability and pharmacokinetical parameters. Biological half-life was negatively correlated (P<0.05) with peak concentration (r=−0.76), absorption rate constant (r=−0.78), and elimination rate constant (r=−0.87). The results indicate that after rapid absorption, hCG remains in the circulation for an extended period. This has to be taken into account when assessing the stimulatory response to hCG treatment on an ovarian level.