[Robotic-assisted laparoscopic living donor nephrectomy: Study in donors and recipients from 155 cases]. / Néphrectomie laparoscopique assistée par robot dans le cadre du donneur-vivant : étude chez les donneurs et les receveurs à partir de 155 cas.

AIM: To evaluate morbidity and renal function of the donor and recipient during a robotic-assisted laparoscopic nephrectomy procedure. PATIENTS AND METHODS: It is a retrospective study of 155 consecutive patients by robot-assisted laparoscopy in the living donor. Mean operating time, warm ischemia time, blood loss, complications according to the Clavien classification and evolution of creatinine clearance were analyzed in the donors. Recovery of graft function, complications and changes in creatinine clearance were observed in recipients. RESULTS: The mean operating time was 176 (±23) minutes. The mean warm ischemia time was 4.8 (±0.6) minutes. Twenty seven complications were noted. The loss of renal function was 19% at 5 years in donors. Renal recovery was immediate for 153 recipients. Two were delayed due to sepsis. Two patients lost their graft at 15 and 18 months. Seventeen complications have been identified. The mean kidney function of the recipients is measured at 63ml/min at 5 years. CONCLUSION: Robotic-assisted laparoscopic nephrectomy procedure appears to provide the donor with low morbidity and a moderate decrease in creatinine clearance at 19% at 5 years. Morbidity is also low in recipients with very satisfactory 5-year mean renal function. The technique should promote donation. LEVEL OF EVIDENCE: 4.

[Current perspectives on the repackaging and stability of solid oral doses]. / Déconditionnement et stabilité des formes orales sèches solides: états des connaissances.

Which are the guidelines and scientific aspects for repackaged oral solid medications in France in 2010 whereas it develops? The transient or definitive displacement of the solid oral form from the original atmosphere to enter a repackaging process, sometimes automated, is likely to play a primary role in the controversy. However, the solid oral dose is to be repackaged in materials with defined quality. Considering these data, a review of the literature for determination of conditions for repackaged drug stability according to different international guidelines is presented in this paper. Attention is also paid to the defined conditions ensuring the conservation and handling of theses drugs throughout the repackaging process. However, there is lack of scientific published stability data. Nevertheless, recent alternatives may be proposed to overcome the complexity of studying stability in such conditions. Then, the comparison of the moisture barrier properties of the respective package, a galenic model of hygroscopic molecules, or light sensitive molecules or stability data obtained during the industrial preformulation phase could also secure the list of drugs to be reconditioned. Similarly, a wise precaution will be to get stability data for the industrial blisters and unit doses undergoing the real conditions of the medication use process in hospitals and other healthcare settings. By now, reduction of dispensing errors and improvement of the compliance aid put a different perspective on the problem of repackaged drugs. To date, the pharmacist is advised to carry out its analysis of the risks.

Absence of placental transfer of pentasaccharide (Fondaparinux, Arixtra) in the dually perfused human cotyledon in vitro.

The synthetic pentasaccharide, fondaparinux, is the first of a new antithrombotic class: selective factor Xa inhibitors. Comparative clinical trials of fondaparinux versus heparins in prevention and treatment of venous thromboembolism are ongoing. Little is known about fondaparinux during pregnancy, as women of child-bearing potential were excluded from clinical trials. No particular safety issue, for either mother or fetus, has been reported for heparins. The objective of this study was to compare in vitro the steady state placental transfer of fondaparinux and enoxaparin at the plasma concentrations reached during acute treatment of venous thromboembolism (1.75 microg/mL and 1 anti-Xa IU/mL respectively), using antipyrine (20 mg/L) as reference. No biological activity was detectable in the fetal venous effluent during perfusion of enoxaparin-antipyrine, fondaparinux-antipyrine or control media. Furthermore, fetal venous samples did not differ significantly from fetal arterial samples. This apparent absence of placental transfer supports further evaluation of fondaparinux in pregnant women.

Placental transfer of SR49059 in the human dually perfused cotyledon in vitro.

SR49059 is an antagonist of vasopressin V(1a)receptors currently developed as a tocolytic drug. We investigated the transplacental transfer of SR49059 in vitro using the single pass dually perfused human cotyledon model. Thirteen placentae were collected from normal term pregnancies immediately after delivery. The placental transfer of SR49059 was tested at steady state at three different concentrations (100 ng/ml, 200 ng/ml and 500 ng/ml) along with that of antipyrine 20 mg/l as a reference substance. Concentrations were assayed by liquid chromatography with UV (antipyrine) or mass spectrometry (SR49059) detection. At steady state, the mean+/-s.d. fetal transfer rate of SR49059 was 10.80+/-4.33 per cent, 9.34+/-4.41 per cent, and 11.78+/-3.26 per cent at 100 ng/ml, 200 ng/ml and 500 ng/ml, respectively. The corresponding clearance indices were 0.29+/-0.14, 0.25+/-0.08, and 0.31+/-0.06, respectively. The absence of saturation kinetics is consistent with a passive mechanism of transfer. Moderate amounts of SR49059 are transferred from the maternal to the fetal circulation. The clearance index of SR49059 appeared to be very similar to that of ritodrine, which is currently used as a tocolytic.

Passage of S-(+)- and R-(-)-ketoprofen across the human isolated perfused placenta.

Ketoprofen is a chiral non-steroidal anti-inflammatory drug (NSAID) available as a racemic (rac) mixture of S-(+)- and R-(-)-isomers. Its inhibitory effect on prostaglandin biosynthesis resides virtually in the S-form. Interestingly, R-ketoprofen does not undergo substantial metabolic inversion in humans. Though contraindicated during the last trimester of pregnancy, NSAIDs, including ketoprofen, are used as tocolytic agents in some cases. The S/R plasma concentration ratio was reported to average 2.3 in premature neonates whose mothers were given rac-ketoprofen and to be close to 1 in the maternal plasma. Thus, we investigated the placental transfer of rac-ketoprofen in vitro using Schneider's perfused human cotyledon model. Glucosed Earle solutions with and without human serum albumin (HSA) were used. Several maternal perfusates were tested with different rac-ketoprofen concentrations together with 20 mg L-1 of antipyrine as a reference substance. Ketoprofen enantiomers were assayed by a specific HPLC method with derivatization procedure. HSA concentrations in maternal perfusate influenced the placental transfer of ketoprofen enantiomers. In the absence of HSA in the maternal perfusate, the S-(+)/R-(-) concentration ratio was close to 1 in the fetal perfusate. By contrast, this ratio averaged 1.44 after addition of HSA 10 g L-1 on the maternal side. Similar results were found for dialysis experiments using an inert Spectrapor 2 membrane suggesting that the S-(+)-free concentration is superior to the R-(-)-free concentration in the presence of HSA. Direct measurements of the free concentrations by centrifugal ultrafiltration confirmed this hypothesis. Accordingly, the data observed in vivo may result, at least in part, from the stereoselective protein binding of ketoprofen.

Determination of buprenorphine in plasma by liquid chromatography: application to heroin-dependent subjects.

A rapid, sensitive, precise and accurate HPLC assay with UV detection was developed for the determination of buprenorphine (BN) in human plasma. This method involved a two-step extraction in the presence of clothiapine as internal standard. The compounds were chromatographied on a reversed-phase Spherisorb C8 column with a mobile phase consisting of 0.06 M KH2PO4/Na2HPO4 pH 6.4-acetonitrile-triethylamine-Pic B5 (520:480:0.5:15, v/v) and detected at 214 nm. The recovery of BN was greater than 94% with an intra-day relative standard deviation < or = 4.8% and an inter-day relative standard deviation < or = 14.6% at any studied level. Studies of drug stability during sample storage at -20 degrees C and at +4 degrees C did not show any significative degradation of BN. This method was successfully applied to explore the overdose state of heroin-dependent subjects treated by high-dose BN.

Binding of ketoprofen enantiomers in various human albumin preparations.

Published data conflict with respect to the enantioselective protein binding parameters of R(-) and S(+) ketoprofen. We studied whether differences in experimental conditions used and/or presence of interfering compounds could provide a possible explanation for these discrepancies. Equilibrium dialysis, supported by ultrafiltration (67 mM Sörensen phosphate buffer pH 7.4, 580 microM HSA, 37 degrees C) allowed the characteristics of the binding sites to be determined according to Scatchard's analysis. (R) and (S)-ketoprofen concentrations were measured by HPLC. The free (R)-ketoprofen/free (S)-ketoprofen (F(R)/F(S)) concentration ratio was calculated. The effect of octanoic acid (OA) found in currently marketed intravenous HSA solutions, and hippuric acid (HA), on F(R)/F(S) concentration ratio was considered. Two classes of binding sites were characterized for both enantiomers. The free (S)-ketoprofen concentrations remained equal to those of the (R)-antipode at low concentrations of racemate (2-35 microg ml(-1)) indicating non-stereoselective albumin binding over the therapeutic range. From 35 microg ml(-1), the free (S)-ketoprofen concentrations were slighty greater than those of its antipode. Both OA and HA induced an increase of the free fraction of the enantiomers by a two-fold to a 15-fold order of magnitude. OA, but not HA, showed a more pronounced effect for the (S)-form leading to a marked decrease in F(R)/F(S) concentration ratio (0.61). Differences in HSA preparations used and/or the presence of interfering compounds may explain the variability in the reported protein binding characteristics of ketoprofen enantiomers.

Influence of a polymeric formulation of ketoprofen on its diffusion into cerebrospinal fluid in rats.

Poly(D,L)lactide nanocapsules (NCs) have been proposed as an alternative carrier for many drugs. We investigated the influence of this formulation on the pharmacokinetics of ketoprofen in the plasma and cerebrospinal fluid (CSF). Male Wistar rats were given intraperitoneal dose of ketoprofen (5 mg/kg) in a suspension of NCs or in a carboxymethylcellulose (CMC) solution (reference preparation). Blood and CSF samples were collected at different times up to 24 h after dosing. The unbound fraction of ketoprofen in plasma (f(u)) was determined using ultrafiltration. The total (C(T)) and free (C(F)) concentrations of ketoprofen in plasma and the simultaneous CSF concentrations (C(CSF)) were measured by a HPLC method and the areas under the curve (AUC(T), AUC(F), AUC(CSF)) were calculated. AUC(T) of ketoprofen-loaded NCs in plasma was similar to that of the reference solution, while AUC(F) of the former (5.41 mg/l x h) was higher than that produced by the latter (4.03 mg/l x h). Accordingly, the unbound fraction (f(u)) was higher after administration of NCs than that of the solution (2.5 and 1.8%, respectively). Finally, AUC(CSF) were identical for both formulations. These findings suggest that the binding of ketoprofen to plasma proteins is not the major factor that governs its blood-to-CSF exchanges.

In vitro distribution of ketoprofen enantiomers in articular tissues of osteoarthritic patients.

The distribution of ketoprofen enantiomers in joint tissues was studied as a function of their relative tissular affinities using the multi-chamber distribution dialysis system described by Bickel et al. Selected off-cuts of synovial membrane, joint capsule, cartilage and ligament were obtained from ten patients suffering from osteoarthritis of the knee (n=3) or hip (n=7). Sörensen solution (4 ml) spiked with racemic ketoprofen (2 microg ml(-1)) was dialysed against 1 ml of the four solutions of tissue homogenates (0.4 g ml(-1)). Ketoprofen enantiomers were quantified in buffer and tissue solutions by high-performance liquid chromatography. The distribution of ketoprofen enantiomers in the Bickel's multi-compartment model indicated that there was a non-stereoselective affinity of ketoprofen enantiomers for their potential target tissues. Despite the interindividual variability in articular tissues, the concentrations (+/-S.D.) of R- and S-ketoprofen were significantly higher in synovial membrane (8.69 (4.76) microg g(-1) for S, 9.14 (5.57) microg g(-1) for R), joint capsule (5.71 (2.49) microg g(-1) for S, 5.49 (2.62) microg g(-1) for R) and ligament (6.28 (3.61) microg g(-1) for S, 6.40 (3.64) microg g(-1) for R) than in articular cartilage (3.67 (1.75) microg g(-1) for S, 3.70 (1.67) microg g(-1) for R). There were no significant differences in the distribution of R- and S-ketoprofen between the solutions of joint capsule, synovium and ligament tissues. These data may be related to differences in ketoprofen affinity for the different constituents of joints. This in vitro distribution profile is similar to that reported in vivo for other non-steroidal anti-inflammatory drugs.

[Plasmatic dosage of antiretroviral drugs by high performance liquid chromathography ]. / Dosage plasmatique des antirétroviraux par chromatographie liquide haute performance.

A high-performance liquid chromatographic method has been developed for the determination of eight antiretroviral drugs (amprenavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir, efavirenz and nevirapine) in a single run. After a liquid-liquid extraction with diethylether, the antiretroviral drugs are separated on a Stability RP18 column eluted with a gradient of acetonitrile and phosphate buffer (50 mM pH 5.65). A sequential ultraviolet detection allowed for simultaneous quantitation of antiretroviral drugs (240, 215, 260 nm). Calibration curves were linear in the range 100-10,000 ng/ml. The limit of quantitation was 50 ng/ml for all drugs except for nevirapine (100 ng/ml). The accuracies ranged from 88.2% to 110.9% and both inter- and intra-day coefficients of variation were lower than 11%. The extraction recoveries were higher than 62%. This method is simple and shows good specificity with respect to commonly coprescribed drugs.

[Exposure to liquid detergent capsules: a study of the cases reported to the Paris Poison Center, 2011-2012]. / Expositions accidentelles d'enfants aux détergents liquides en capsules : expérience du centre antipoison de Paris (2011-2012).

OBJECTIVE: To evaluate the toxicity of liquid detergent capsules for children. METHODS: Analysis of 684 consecutive cases from the Paris Poison Center (2011-2012). RESULTS: Most enquiries (97 %) concerned children 5 years of age or younger. The main circumstances of exposure were ingestion alone (72.4 %) or together with eye or skin contact (7.5 % and 7.3 %, respectively). The effects observed were generally due to the irritating properties of concentrated detergents: minor digestive disturbances (particularly vomiting in nearly 50 % of cases) after ingestion and conjunctivitis and/or keratitis after eye contact. The main complications were 24 cases of keratitis and one case of pulmonary toxicity after ingestion. A rash was observed in nine patients; it was delayed in two. CONCLUSIONS: The effects observed with liquid detergent capsules were very similar to those resulting from exposure to other detergents. However, exposure to these agents are very frequent and often results in eye contact, which may be responsible for keratitis, and after ingestion detergent inhalation is a possible complication. All cases with eye symptoms or cough after liquid detergent capsule exposure deserve prompt medical examination and assistance. Greater awareness of both health professionals and consumers on the dangers and risks of these laundry detergent pods is required for better treatment of exposure accidents and for their prevention.

Toxicological management of chlorophacinone poisoning.

A 33-year-old man was admitted 8 hours after voluntary ingestion of 1875 mg of chlorophacinone (C'Operat 750 mL). The examination revealed excitation and nausea, with a normal prothrombin index (PI). Comprehensive testing for abused and therapeutic drugs in blood confirmed chlorophacinone (maximum plasma level: 27.6 mg/L), an antivitamin K (AVK) rodenticide. In a search for easy toxicological management of chlorophacinone poisoning treated by phytomenadione and a cytochrome P450 inducer (phenobarbital), PI and chlorophacinone plasma levels were monitored concomitantly during 17 days. A simple HPLC procedure for the determination of chlorophacinone in human plasma is reported for that purpose. Under phenobarbital 200 mg/day, chlorophacinone exhibited an apparent elimination half-life (3.27 days) shorter than in previously reported cases. If PI is useful for planning phytomenadione treatment and used for therapeutic monitoring of AVK, the chlorophacinone concentrations follow-up may provide a better estimation of the duration of hospitalisation. Chlorophacinone accumulation in target cells or existence of an unidentified metabolite may explain persistence of the hypocoagulability syndrome at low plasmatic concentrations of chlorophacinone. This case illustrates how toxicological management may facilitate toxicokinetics and therapeutic data acquisition.

Influence of molecular lipophilicity on the diffusion of arylpropionate non-steroidal anti-inflammatory drugs into the cerebrospinal fluid.

The diffusion of seven arylpropionic acid non-steroidal anti-inflammatory drugs (NSAIDs) into the cerebrospinal fluid (CSF) has been investigated in male Wistar rats by means of quantitative structure-activity relationship (QSAR) study. After intraperitoneal administration of each drug (5 mg/kg), blood and CSF samples were collected at different times (0.5, 1, 3, and 6 h). The fraction bound to plasma proteins (fb) was determined using ultracentrifugation. The total (CT) and free (CF) plasma concentrations and the concentrations in CSF (CCSF) were measured by a reversed-phase high performance liquid chromatographic (RP-HPLC) method. The areas under the curve of the free plasma (AUCF) and CSF (AUCCSF) concentrations were calculated according to the trapezoidal rule. The overall drug transit into CSF was estimated by the ratio RAUC (AUCCSF: AUCF). The lipophilicity of the compounds was expressed as their polycratic capacity factors (log k'w) measured in a RP-HPLC system. The RAUC ranged from 0.24 to 6.58 and fb from 91.4 to 99.8%. The compounds with an intermediate lipophilicity value (3 < logk'w < 3.6) easily entered the CSF (RAUC > 1). A parabolic relationship was found between log k'w and log RAUC, emphasizing the role of molecular lipophilicity in the diffusion into CSF. Considering the fb value of each drug in regard to this non-linear relationship, it can be hypothesized that the diffusion rate of NSAIDs into the CSF depends primarily on the lipophilicity.

Single and multiple dose pharmacokinetics of acetaminophen (paracetamol) in polymedicated very old patients with rheumatic pain.

OBJECTIVE: To determine whether multiple dosing of acetaminophen would result in drug accumulation in polymedicated elderly patients with rheumatic pain. METHODS: Twelve inpatients (11 women), aged 89 +/- 4 years, weight 59 +/- 10 kg, receiving 3 to 8 concomitant medications, entered the study. Their creatinine clearance according to the Cockroft-Gault formula was 42 +/- 12 ml/min. The pharmacokinetics of 1 g acetaminophen was evaluated after the first dose (D1) and after the last dose (D7) during a 3 times daily regimen of 1 g for 5 consecutive days. RESULTS: The plasma pharmacokinetic profile of acetaminophen did not change significantly at D7 compared to D1. No significant within-patient differences were observed, especially with respect to plasma elimination half-life (2.74 +/- 0.48 and 2.77 +/- 0.32 hours, respectively), area under the concentration-time curve (82.5 +/- 21.1 and 90.1 +/- 15.2 microg x h/ml, respectively), and apparent oral clearance (3.68 +/- 0.85 and 3.28 +/- 0.52 ml/min/kg, respectively). CONCLUSION: No drug accumulation occurred during multiple dosing with acetaminophen in these very old subjects. On the basis of pharmacokinetic data alone, a dose regimen of acetaminophen 1 g tid seems to be appropriate in such patients.