キヌプリスチン

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 7.3X10+8(SRC), determined from a structure estimation method(2), indicates that quinupristin is expected to be immobile in soil(SRC). Volatilization of quinupristin from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.0X10-28 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Quinupristin is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.5X10-43 mm Hg at 25 °C(SRC), determined from a fragment constant method(4). Biodegradation data in soil were not available(SRC, 2012).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 7.3X10+8(SRC), determined from a structure estimation method(2), indicates that quinupristin is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.0X10-28 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 2(SRC), from an estimated log Kow of 1.80(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2012).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), quinupristin, which has an estimated vapor pressure of 1.5X10-43 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase quinupristin may be removed from the air by wet or dry deposition(SRC). Quinupristin contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of quinupristin can be estimated to be 7.3X10+8(SRC). According to a classification scheme(2), this estimated Koc value suggests that quinupristin is expected to be immobile in soil.

/CASE REPORTS/ There are four reports of patients receiving Synercid doses at up to three times that recommended (7.5 mg/kg). No adverse events were considered possibly or probably related to Synercid overdose. Signs of acute overdosage may include dyspnea, emesis, tremors, and ataxia as seen in animals given extremely high doses (50 mg/kg) of Synercid.

/CASE REPORTS/ Quinupristin/Dalfopristin is a new combination of streptogramin antibiotics designed specifically to treat clinically significant infections due to Vancomycin-resistant Enterococcus Faecium. Sweet's syndrome is characterized by painful skin plaques, which is associated with dermal neutrophilic infiltration, fever and peripheral blood leukocytosis. Drug-induced Sweet's syndrome has a temporal relationship between drug ingestion, clinical presentation and the temporally-related resolution of lesions following drug withdrawal or on treatment with systemic corticosteroids. A 63-year-old woman received Quinupristin/Dalfopristin for acute pyelonephritis developed fever, arthralgia, vomiting, and painful erythematous skin plaques. A skin biopsy showed neutrophilic dermatosis, and there was rapid resolution of the symptoms and cutaneous lesions after discontinuation of Quinupristin/Dalfopristin, consistent with drug-induced Sweet's syndrome.

/EPIDEMIOLOGY STUDIES/ To evaluate risk factors for the development of arthralgias or myalgias associated with quinupristin-dalfopristin, ... All adult and pediatric patients who had received quinupristin-dalfopristin through either a compassionate-use protocol (February 1996-October 1999) or in the year after quinupristin-dalfopristin was added to the hospital formulary (November 1999-October 2000) were included in this study. Case patients were those who developed arthralgias or myalgias while receiving quinupristin-dalfopristin therapy; control patients were those who received quinupristin-dalfopristin but did not develop arthralgias or myalgias. Medical records, pharmacy dispensing information, and microbiology data were reviewed by a physician and a pharmacist, both of whom specialized in infectious diseases. Presence or absence of arthralgias or myalgias was the primary outcome assessed. Quinupristin-dalfopristin was administered to 68 patients during the period defined by the study. Arthralgias and myalgias could not be assessed in 18 of the 68 patients because they were sedated and paralyzed, or they were young children who could not communicate the presence of pain. Univariate analysis demonstrated that significant risk factors for arthralgias or myalgias associated with quinupristin-dalfopristin were female sex, chronic liver disease, receipt of liver transplant, elevated bilirubin level at baseline, major surgery, and receipt of either mycophenolate or cyclosporine. Multivariate analysis demonstrated a strong association with chronic liver disease, receipt of liver transplant, elevated bilirubin level at baseline, and receipt of either cyclosporine or mycophenolate. Of 50 evaluable patients receiving quinupristin-dalfopristin, 25 had pain that may have been associated with this antimicrobial agent. The mechanism for development of arthralgias or myalgias associated with quinupristin-dalfopristin remains unknown, but these adverse events are more likely to occur in patients with chronic liver disease and those who have received a liver transplant or are receiving cyclosporine or mycophenolate.

/ALTERNATIVE and IN VITRO TESTS/ Infusion phlebitis is a common clinical problem that is observed with some antimicrobial agents, when being administered intravenously. In this study, cultured murine fibroblasts and immortalised human endothelial cells were exposed to three antibiotics at clinically relevant concentrations to assess their toxic potential in two established cytotoxicity assays. BALB/c 3T3 fibroblasts and Eahy926 endothelial cells were exposed to quinupristin/dalfopristin (QD), erythromycin and levofloxacin at increasing concentrations. For assessment of cytotoxicity the cells were incubated with neutral red (NR) or stained with crystal violet (CV). Measurements were done by photometry. At the concentration range tested QD and erythromycin showed a concentration-dependent cytotoxic effect in both cell cultures. In 3T3 cells the half-maximal effect concentration (EC50) was 20 mg/l for QD and 340 mg/l for erythromycin in the NR uptake test and 12 and 200 mg/l, respectively, in the CV assay. In Eahy926 cells the EC50 was 50 mg/l for QD and 880 mg/l for erythromycin in the NR uptake test and 40 and 750 mg/l, respectively, in the CV assay. No EC50 could be established in both cell types for levofloxacin. Eahy926 cells were less sensitive to cytotoxic stimuli than 3T3 fibroblasts. Cytotoxic effects in both cell cultures occurred in the following order: QD > erythromycin >> levofloxacin. This ranking correlates well with the frequency of local adverse effects observed with the infusion of these antibiotics in patients. Thus, these in vitro assays may serve as an estimate for the prediction of local tolerability of antibiotics when administered parenterally.

An estimated BCF of 2 was calculated in fish for quinupristin(SRC), using an estimated log Kow of 1.80(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for quinupristin is estimated as 2.0X10-28 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that quinupristin is expected to be essentially nonvolatile from water surfaces(2). Quinupristin is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.5X10-43 mm Hg(SRC), determined from a fragment constant method(3).

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Reproductive studies have been performed in mice at doses up to 40 mg/kg/day (approximately half the human dose based on body-surface area), in rats at doses up to 120 mg/kg/day (approximately 2.5 times the human dose based on body-surface area), and in rabbits at doses up to 12 mg/kg/day (approximately half the human dose based on body-surface area) and have revealed no evidence of impaired fertility or harm to the fetus due to Synercid.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ No impairment of fertility or perinatal/postnatal development was observed in rats at doses up to 12 to 18 mg/kg (approximately 0.3 to 0.4 times the human dose based on body-surface area).

/GENOTOXICITY/ Five genetic toxicity tests were performed. Synercid, dalfopristin, and quinupristin were tested in the bacterial reverse mutation assay, the Chinese hamster ovary cell HGPRT gene mutation assay, the unscheduled DNA synthesis assay in rat hepatocytes, the Chinese hamster ovary cell chromosome aberration assay, and the mouse micronucleus assay in bone marrow. Dalfopristin was associated with the production of structural chromosome aberrations when tested in the Chinese hamster ovary cell chromosome aberration assay. Synercid and quinupristin were negative in this assay. Synercid, dalfopristin, and quinupristin were all negative in the other four genetic toxicity assays.

... The mechanism for development of arthralgias or myalgias associated with quinupristin-dalfopristin remains unknown, but these adverse events are more likely to occur in patients with chronic liver disease and those who have received a liver transplant or are receiving cyclosporine or mycophenolate.

Quinupristin expected to undergo hydrolysis in the environment process since this compound contains functional groups (carboxylic ester) that hydrolyze under basic conditions(1). Quinupristin contains chromophores that absorb at wavelengths >290 nm(1) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

Occupational exposure to quinupristin may occur through inhalation and dermal contact with this compound at workplaces where quinupristin is produced or administereed. Exposure to quinupristin among the general population will be limited to those administered the drug, an antibiotic. (SRC)

While data specific to quinupristin were not located(SRC, 2012), the literature suggests that some pharmaceutically active compounds originating from human and veterinary therapy are not eliminated completely in municipal sewage treatment plants and are therefore discharged into receiving waters(1). Wastewater treatment processes often were not designed to remove them from the effluent(2). Selected organic waste compounds may be degrading to new and more persistent compounds that may be released instead of or in addition to the parent compound(2).

3.1 hours

The elimination half-life of quinupristin and dalfopristin is approximately 0.85 and 0.70 hours, respectively.

The pharmacokinetics of quinupristin/dalfopristin have been studied in rats, monkeys and humans following intravenous infusion of radiolabelled and unlabelled drug. ... The blood elimination half-life of quinupristin was approximately 0.6 hr in rats and 0.5 hr in monkeys, and that of dalfopristin was approximately 0.6 hr and 0.2 hr, respectively. ... Following intravenous administration both compounds are rapidly cleared from the blood with elimination half-lives of approximately 1 hr for quinupristin and 0.4-0.5 hr for dalfopristin.

Quinupristin is converted to two conjugated active major metabolites, one with glutathione and one with cysteine.

Quinupristin and dalfopristin are converted to several major active metabolites: 2 conjugated (with glutathione and cysteine) metabolites for quinupristin and one nonconjugated (formed by hydrolysis) metabolite for dalfopristin, which also act synergistically with the complementary parent drug. This conversion occurs in vitro by nonenzymatic reactions independent of cytochrome P-450 (CYP) and glutathione transferase enzymes.

23OW28RS7P

QUINUPRISTIN

Established Pharmacologic Class [EPC] - Streptogramin Antibacterial

Chemical Structure [CS] - Streptogramins

Quinupristin is a Streptogramin Antibacterial.

Quinupristin and dalfopristin is distributed into milk in rats ... .

The pharmacokinetics of quinupristin/dalfopristin have been studied in rats, monkeys and humans following intravenous infusion of radiolabelled and unlabelled drug. In rats and monkeys quinupristin and dalfopristin undergo rapid elimination from the blood and wide tissue distribution. Nevertheless, they do not penetrate the central nervous system or cross the placenta to any significant degree and they do not appear to be subject to significant body retention following cessation of administration. The blood elimination half-life of quinupristin was approximately 0.6 hr in rats and 0.5 hr in monkeys, and that of dalfopristin was approximately 0.6 hr and 0.2 hr, respectively. Both compounds are primarily eliminated through the bile into the faeces; quinupristin is mainly excreted unchanged whereas dalfopristin is extensively metabolized beforehand. The metabolites include the microbiologically active pristinamycin PIIA for dalfopristin and the microbiologically active glutathione- and cysteine-conjugated derivatives for quinupristin. Quinupristin and dalfopristin appear to be handled in a similar manner by humans. Following intravenous administration both compounds are rapidly cleared from the blood with elimination half-lives of approximately 1 hr for quinupristin and 0.4-0.5 hr for dalfopristin. The pharmacokinetic profile of quinupristin is dose-independent and so is that of dalfopristin and RP 12536 when considered together. Extravascular diffusion of quinupristin/dalfopristin has been assessed in human non-inflammatory interstitial fluid.

Fecal excretion constitutes the main elimination route for both parent drugs and their metabolites (75 to 77% of dose). Urinary excretion accounts for approximately 15% of the quinupristin and 19% of the dalfopristin dose. Preclinical data in rats have demonstrated that approximately 80% of the dose is excreted in the bile and suggest that in man, biliary excretion is probably the principal route for fecal elimination.