A dynamical measure of the black hole mass in a quasar 11 billion years ago

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH)1-3. These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase4-6. A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3)7. Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-μas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 108 solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 1011 solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems.

[Raman spectroscopy applied to analytical quality control of injectable drugs: analytical evaluation and comparative economic versus HPLC and UV / visible-FTIR]

In France, central IV admixture of chemotherapy (CT) treatments at the hospital is now required by law. We have previously shown that the shaping of Therapeutic Objects (TOs) could profit from an Analytical Quality Assurance (AQA), closely linked to the batch release, for the three key parameters: identity, purity, and initial concentration of the compound of interest. In the course of recent and diversified works, we showed the technical superiority of non-intrusive Raman Spectroscopy (RS) vs. any other analytical option and, especially for both HPLC and vibrational method using a UV/visible-FTIR coupling. An interconnected qualitative and economic assessment strongly helps to enrich these relevant works. The study compares in operational situation, the performance of three analytical methods used for the AQC of TOs. We used: a) a set of evaluation criteria, b) the depreciation tables of the machinery, c) the cost of disposables, d) the weight of equipment and technical installations, e) the basic accounting unit (unit of work) and its composite costs (Euros), which vary according to the technical options, the weight of both human resources and disposables; finally, different combinations are described. So, the unit of work can take 12 different values between 1 and 5.5 Euros, and we provide various recommendations. A qualitative evaluation grid constantly places the SR technology as superior or equal to the 2 other techniques currently available. Our results demonstrated: a) the major interest of the non-intrusive AQC performed by RS, especially when it is not possible to analyze a TO with existing methods e.g. elastomeric portable pumps, and b) the high potential for this technique to be a strong contributor to the security of the medication circuit, and to fight the iatrogenic effects of drugs especially in the hospital. It also contributes to the protection of all actors in healthcare and of their working environment.

[Antibiotic treatment of appendicular peritonitis in children: is the oral route done?]

The use of intravenously administered antibiotics has several disadvantages including hospitalization costs, infectious risk, and patient discomfort. The objective of this study was to estimate the proportion of children receiving intravenous antibiotic therapy (IV), for whom there was a switch to an oral route conforming to the criteria established by the American Pediatric Surgical Association (APSA). A cohort of 100 children hospitalized for acute appendicitis with generalized peritonitis or abscess were analyzed. In this study, we compared the criteria of switching to an oral route as recommended by the APSA (disappearance of the pain, normalization of white blood cells, afebrile for 48 hours, return to bowel function) and by reports from the literature (afebrile, tolerating regular diet). In 47.5% of the children, there was a switch to an oral route conforming to the APSA recommendations. In children having a late switch, the average duration of the IV treatment was of 7.6 ± 3.6 days associated with 62 days of avoidable IV antibiotics. The duration of hospitalization and antibiotic treatment was significantly higher in children having a late switch (P=0.04; P=0.01, respectively). Concerning the criteria reported in the literature, 14.5% of children were not switched to an oral route. Meeting the criteria from the literature would have resulted in 199 days of avoidable IV antibiotics. A significant number of days of IV antibiotics could have been avoided. However, the large number of exclusion criteria in the APSA analysis suggests that practitioners do not follow these recommendations or objective criteria. The criteria proposed in the literature could decrease the duration of IV antibiotics and the associated hospitalization costs.

Safety and quality assurance of chemotherapeutic preparations in a hospital production unit: Acceptance sampling plan and economic impact

Objective: The opportunity to apply a sampling plan was evaluated. Costs were computed by a microcosting study.

Setting: In 2003, a sampling plan was defined to reduce the number of chemotherapy quality controls while preserving the same level of quality. Recent qualitative and quantitative changes led us to define a second sampling plan supplemented by an economic evaluation to determine the cost and cost-savings of quality control.

Methods: The study considers preparation produced during four semesters classified into three groups. The first one includes drugs produced below 200 batches a semester. Group 2, those for which the lot of preparation lots would have been rejected twice among these four semesters. Group 3, those would have been accepted (≥3 ‘acceptable lot’). A single sampling plan by attributes was applied to this group with an acceptance quality level of 1.65% and a lot tolerance percent defective below 5%. A micro-costing study was conducted on quality control, from the sampling to the validation of the results.

Results: Among 39 cytotoxic drugs, 11 were sampled which enabled to avoid a mean of 17,512 control assays per year. Each batch of the 28 non-sampled drugs was however analyzed. Costs were estimated at 2.98€ and 5.25€ for control assays depending of the analytical method. The savings from the application of the sampling plans was 153,207€ in 6 years.

Conclusion: The sampling plan allowed maintaining constancy in number of controls and the level of quality with significant costsavings, despite a substantial increase in drugs to assay and in the number of preparations produced.

Evaluation of the pharmacokinetic profile and analgesic efficacy of oral morphine after total hip arthroplasty

BACKGROUND AND OBJECTIVE

Oral morphine may be useful for postoperative pain relief, but few studies have tested its use after in-hospital surgery.

METHODS

We evaluated clinical efficacy and the pharmacokinetic parameters of oral morphine after total hip arthroplasty. We recruited 60 patients who had total hip arthroplasty under general anaesthesia. The patients were randomized to receive placebo, 10 mg morphine sulphate or 20 mg morphine sulphate orally every 4 h for 24 h. The oral administration was started 3 h after the morphine-loading dose in the Post Anaesthesia Care Unit and then patients used intravenous morphine patient-controlled analgesia for 24 h. Pain score at rest (scored by patients on a visual analogue scale), sedation, nausea, vomiting and urinary retention were monitored. In 11 additional total hip arthroplasty patients, we determined the pharmacokinetics of morphine and its metabolites after oral administration of 20 mg morphine sulphate every 4 h for 16 h.

RESULTS

The amount of morphine administered via patient-controlled analgesia over 24 h was reduced in the 20-mg group compared with that in the placebo group (19.0 +/- 2.7 mg vs. 33.0 +/- 5.5 mg; P = 0.03). No significant morphine-sparing effect was observed in the 10-mg group. Pain scores and side-effects were similar in all groups. The pharmacokinetic study revealed a limited and slow absorption of morphine.

CONCLUSION

Despite a limited absorption of oral morphine postoperatively, high doses of oral morphine have a significant analgesic effect after total hip arthroplasty.

Near infrared spectroscopy and process analytical technology to master the process of busulfan paediatric capsules in a university hospital

The prescription of unlicensed oral medicines in paediatrics leads the hospital pharmacists to compound hard capsules, such as busulfan, an alkylating agent prescribed in preparative regimens for bone marrow transplantation. In this study, we have investigated how the general principle of process analytical technology (PAT) can be implemented at the small size of our hospital pharmacy manufacturing unit. Near infrared spectroscopy (NIRS) was calibrated for raw material identification, blend uniformity analysis and final content uniformity of busulfan hard capsules of 11 different strengths. Measurements were performed on capsules from 2 to 40 mg (n=440). After optimisation, accuracy and linearity of the NIRS quantitative method was demonstrated after comparison with a previously validated quantitative high performance thin layer chromatography (HPTLC) method. Such a comparison led to attractive NIRS precision: +/-0.7 to +/-1.0 mg for capsules from 2 to 40 mg, respectively. As NIRS is a rapid and non-destructive technique, the individual control of a whole batch of busulfan paediatric capsules intended to be administrated is possible. Actually, mastering the process of busulfan paediatric capsules with the NIRS integrated into the notion of PAT is a powerful analytical tool to assess the process quality and to perform content uniformity of at least 5mg busulfan-containing capsules.

[Shelf-lives of morphine and pethidine solutions stored in patient-controlled analgesia devices: physico-chemical and microbiological stability study]

Morphine and meperidine in Patient-Controlled Analgesic devices are commonly used to treat chronic pain patients. These devices deliver a programmed amount of drug and allow self-administration by the patient depending on the pain. In our department of pharmacy, 300 devices were manufactured in 2003. The aim of this study was to assess their shelf-life. The devices were filled aseptically and without preservatives with 1 and 40 mg/ml morphine solution and 5 and 20 mg/ml meperidine and stored over 30 days at room temperature and protected from light. Culture assay of the solutions showed that they remained sterile for 30 days. No turbidity of any solutions from samples collected twice a week was noticed. pH and osmolarity remained constant. Drug concentrations were determined using stability indicating HPLC method, as we showed that degradation products can be separated from the drugs. Little loss of meperidine occurred within 21 days (<5%) and morphine concentration, which increased, because of solvent evaporation, remained lower than 5% within 21 days but increased up to 10% after 30 days. No traces of degradation products (pseudomorphine or pethidic acid) were detected. The physicochemical and microbiological stability of morphine and meperidine hydrochlorides stored in such devices has been established for 21 days at room temperature and protected from light.

Heated intra-operative intraperitoneal oxaliplatin plus irinotecan after complete resection of peritoneal carcinomatosis: pharmacokinetics, tissue distribution and tolerance

BACKGROUND

The purpose of this study was to report the pharmacokinetics (PK) and tolerance profile of intraoperative intraperitoneal chemo-hyperthermia (IPCH) with oxaliplatin and irinotecan.

PATIENTS AND METHODS

Thirty-nine patients with peritoneal carcinomatosis (PC) of either gastrointestinal or peritoneal origin underwent complete cytoreductive surgery followed by IPCH with a stable dose of oxaliplatin (460 mg/m(2)), plus one among seven escalating doses of irinotecan (from 300 to 700 mg/m(2)). IPCH was carried out with the abdomen open, for 30 min at 43 degrees C, with 2 l/m(2) of a 5% dextrose instillation in a closed continuous circuit. Patients received intravenous leucovorin (20 mg/m(2)) and 5-fluorouracil (400 mg/m(2)) just before IPCH to maximize the effect of oxaliplatin and irinotecan.

RESULTS

Irinotecan concentration in tumoral tissue increased until 400 mg/m(2) and then remained stable despite dose escalations. It was 16-23 times higher than in non-bathed tissues. Increasing doses of intraperitoneal irinotecan did not modify the PK of intraperitoneal oxaliplatin, and the drug concentration ratio was 17.8 higher in tumoral tissue (bathed) than in non-bathed tissues. The hospital mortality rate was 2.5% and the non-hematological complication rate was 25%. However, grade 3-4 hematological toxicity rate was 58%.

CONCLUSION

Intraperitoneal heated oxaliplatin (460 mg/m(2)) plus irinotecan (400 mg/m(2)) presented an advantageous PK profile and was tolerated by patients, despite a high hematological toxicity rate.

Identification and quantitation of antineoplastic compounds in chemotherapeutic infusion bags by use of HPTLC: application to the vinca-alkaloids

An instrumental quantitative high-performance thin-layer chromatographic (HPTLC) method has been developed for the determination of vinca-alkaloids (antineoplastic compounds) in chemotherapeutic infusion bags prepared in a hospital pharmacy. The method uses automated band application onto silica gel plates containing a fluorescent indicator and scanning densitometry of fluorescence-quenched zones of samples and standards. Samples were analyzed to check the content of the active substance against the label declaration of the preparation. The four compounds were separated using the following solvent system CH(2)Cl(2)-CH(3)OH (93:7, v/v). Vincristine (VCR) and vinorelbine (NVB) were assessed in the same run whilst vinblastine (VLB) and vindesine (VDS) were analyzed in a second run. HPTLC allows the identification and the quantitation of more than 20 samples in the same chromatographic run. The analysis of the samples requires 30 min compared with more than 2 h using a typical HPLC method. Moreover, there is no need for a conditioning step, as with HPLC, and each analysis by HPTLC is less expensive.

Human pharmacokinetic study of heated intraperitoneal oxaliplatin in increasingly hypotonic solutions after complete resection of peritoneal carcinomatosis

PURPOSE

We studied the pharmacokinetics of heated intraoperative intraperitoneal (i.p.) oxaliplatin (LOHP) solution and its safety profile in increasingly hypotonic solutions. This is the first clinical study of i.p. chemohyperthermia with hypotonic solutions.

METHODS

Patients with peritoneal carcinomatosis (PC) underwent complete cytoreductive surgery followed by intraoperative i.p. chemohyperthermia (IPCH) with successive dextrose solutions of 300, 200, 150 and 100 mosm/l. LOHP (460 mg/m(2)) was administered in 2 liters of solution/m(2) at an i.p. temperature of 42-44 degrees C for 30 min. IPCH was performed using an open procedure (skin pulled upwards) with a continuous closed circuit. Patients received intravenous leucovorin (20 mg/m(2)) and 5-fluorouracil (400 mg/m(2)) just before IPCH to maximize the effect of LOHP. i.p. plasma and tissue samples were analyzed by means of atomic absorption spectrophotometry. Sixteen consecutive patients with PC of either gastrointestinal or peritoneal origin were treated. The safety of the procedure was studied.

RESULTS

Pharmacokinetics: The mean duration of the entire procedure was 7.7 +/- 2.6 h. Half the LOHP dose was absorbed within 30 min at all dose levels. Absorption was not higher with hypotonic solutions than with isotonic solutions. The area under the curve of LOHP in plasma did not increase with decreasing osmolarity of the i.p. solutions. Intratumoral LOHP penetration was high; it was similar to that at the peritoneal surface, and about 18 times higher than that in nonbathed tissues. LOHP penetration was not significantly increased by using hypotonic solutions.

SAFETY

There was a very high incidence of unexplained postoperative peritoneal bleeding (50%) and unusually severe thrombocytopenia in the 150 and 100 mosm/l groups.

CONCLUSION

Contrary to experimental studies, this clinical study showed no increase in tumoral or systemic penetration of LOHP with i.p. hypotonic solutions (200, 150 or 100 mosm/l) during IPCH. A high incidence of i.p. hemorrhage and thrombocytopenia was observed.

[Pharmaceutical traceability integrated with the patient file. Development of a computerized hospital application]

The Clinical Pharmacy Department (CPD) of the Gustave Roussy Institute, has developed a traceability software package that is integrated with the patient file. The Traceability & Medical Devices Functional Unit manages the Blood Derivative Medicinal Product traceability circuits, the circuits of over 400 Sterile Medical Devices and, generally speaking, those for all pharmaceutical goods for which traceability is imperative. The SIMBAD-TRACE software package has been developed in situ and was first open for access in March 1999. It enables pharmaceutical traceability data to be accessed from 500 networked workstations. The references tracked generated about 10,000 movements per year. In terms of performance, the system achieves three complementary objectives: 1) reporting traceability scores which reflect the ability of CPD and the establishment to pertinently respond to a complex regulatory requirement on a daily basis; 2) the contribution of the tool to cost containment with respect to allocating rare goods; the contribution of the software package to the implementation of medical device vigilance inquiries, particularly descending inquiries. Finally, SIMBAD-TRACE is one of the pillars of our Quality Assurance Program (QAP).

Application of high-performance, thin-layer chromatography to quality control of antimetabolite analogue infusion bags

A global postproduction quality program was developed to secure chemotherapy infusion at the Gustave Roussy Institute. Despite rigorous procedures and computerized prescriptions, an analytical check was necessary to improve the quality of ready-to-use solutions of cytotoxic drugs in our Centralized Antineoplastics Reconstitution Unit. High-performance, thin-layer chromatography was selected as the analytical tool to assay 12 anticancer drugs. One of the analytical methods can separate 4 antimetabolite substances, i.e., fludarabine (FDB), cytarabine (CTB), gemcitabine (GTB), and fluorouracil (5 FU). For all infusion bags manufactured, up to 26 samples could be assayed per series using a double standard calibration (GTB and 5 FU).

[Role and functional spectrum of HPTLC in a hospital pharmaceutical quality control program]

As part of the development of a quality assurance program (QAP), a high performance thin layer chromatography (HPTLC) analysis unit was installed in the pharmacy department at Gustave-Roussy. The HPTLC-CAMAG consists of: 1) an HPTLC-Vario development chamber for optimization of the mobile phases; 2) TLC Sampler III automated sample applicators; 3) solid teflon migration chambers, i.e., horizontal tanks that enable separation to be carried out either in sandwich or in saturation mode; 4) a TLC Scanner 3 densitometer controlled by CATS 4 software; and 5) a Pentium MMX 233 MHz personal computer with an external backup unit. HPTLC quantitative and qualitative analysis has now reached a remarkably high level of development and performance. The samples (aqueous or non-aqueous solutions) that are to be processed are automatically applied by spraying (50-300 nl) in calibrated bands of a few mm (with up to 64 3-mm bands per 10 x 20 cm plate) on high-performance stationary phases and of wide technological diversity. The chromatogram is obtained in 10 min, and run over a migration pathway of 5-6 cm. The plates are read by absorption-reflection or fluorescence-reflection at an ad hoc wavelength (190-800 nm), then the peak areas which have been scanned are calculated by the trapezoid method. The calibration curves are generated by Michaelis-Menten non-linear regression, and validated by internal quality control. The analytical yield is high, i.e., up to 50 assays and 250 determinations per day. HPTLC analysis covers a wide functional range, and can be used in the following ways: 1) as a teaching tool for separative analysis and GLP; 2) it is an invaluable method for the optimization of mobile phases and for the determination of absorption spectra and absorption maxima, with a view to developing HPLC methods in complex matrices; 3) it provides major support for post-production quality control of prescribed hospital preparations of all types, e.g., those connected with parenteral nutrition, chemotherapy, synthetic narcotic analgesia; and it can also be used for dry dosage analysis; 4) it is useful in pharmaceutical assessment, e.g., in studies on the physico-chemical characteristics of various substances, such as their identity, purity, concentration, stability and compatibility, particularly with regard to generic products; 5) it can contribute to monitoring the safety of medical apparatus and equipment via the analysis of container-content interactions; 6) it provides a qualification system for personnel and procedures for within- and between-center validation of GMP. Setting up such an HPTLC quality control unit requires a basic investment of about 0.9 MF or 70,000 US dollars for a cost of no more than 10 F or 1.5 US dollars (including tax) per routine assay. After 18 months in operation and 16,500 assays, the HPTLC analysis unit has become one of the mainstays of the Gustave-Roussy QAP.

Clinical pharmacokinetics of ciprofloxacin in patients with major burns

OBJECTIVE

To better master the use of ciprofloxacin (CPF) in burn patients, a clinical study, including pharmacokinetics in serum and urine, was undertaken in a pathophysiologically homogeneous population of major-burn subjects.

METHODS

Twelve major-burn patients who were infected with Pseudomonas aeruginosa, enterobacteria and gram-positive cocci, received CPF (600 mg t.i.d.). The mean body surface area affected by third-degree burns was 31.8 +/- 14.5%. Two series of blood samples were drawn after the first and seventh doses; urine was collected during the first infusion. Levels of CPF in serum and urine were measured by means of high-performance liquid chromatography. A non-compartmental method was used for kinetic and graphic analysis of concentration-time pairs.

RESULTS

No adverse effects were noted. Trough concentrations measured on day 3 (mean +/- SD) were above the minimum inhibitory concentration (MIC) for the organism responsible for infection; i.e., 2.0 +/- 1.2 microg. ml(-1), and maximum concentrations were high 9. 9 +/- 3.4 microg. ml(-1). An area under the concentration-time curve (AUC)/MIC ratio above 125 SIT(-1) (where SIT is the serum inhibitory titer), which has been strongly correlated with clinical response and time to bacterial eradication, was achieved in 11 patients with a MIC of 0.5 microg. ml(-1). There was a statistically significant difference between C(min) and AUC determined on day 1 and day 3. In contrast to healthy volunteers, CPF clearance rates were notably decreased.

CONCLUSION

The pharmacokinetics of CPF was altered in major-burn patients. The recommended dosage regimen for administration of CPF, i.e. 600 mg t.i.d. shows no adverse effects and a good microbiological efficacy.

[Pharmacokinetics of fusidic acid in patients with seriously infected burns]

The pharmacokinetics of fusidic acid (FA) were studied in 10 infected severe burns patients (35 +/- 5 yrs, 81 +/- 17 kg) i.e. 43 +/- 10% in 3rd degree. Treatment was given at the dose of 500 mg/8 hours (2-hour infusion). The kinetics of FA were evaluated on D1 (1st infusion) and at steady state on D4 (10th infusion), each sequence involving 9 whole blood samples. Samples were assayed by high-performance liquid chromatography. Data were analysed by a non-compartmental method. Mean duration of treatment, considered effective in all cases, was 5.9 +/- 2.1 days. The systemic safety of FA was felt to be good. Kinetic analysis revealed the existence of significant differences between D1 and D4 concerning the parameters Cmax, Cmin, AUC, Cl and Vss. These events are attributable to the non-linear nature of the human kinetics of FA. Accumulation ratios R1 and R2 did not differ i.e. 1.51 +/- 0.25 and R2 = 2.44 +/- 0.68. Kinetic modelling based upon the experimental tracing obtained on D1 revealed good coincidence of the predictive tracing in relation to data determined on D4. The dosage algorithm of 500 mg/8 hours was microbiologically satisfactory with Cmin measured on D1 and at steady state constantly greater than the MIC of the main organisms concerned (< to 2 micrograms/ml). Reduction in the parameters Cmax and AUC in comparison with a group of healthy subjects ultimately led to shortening of the mean T1/2 of FA. In the absence of impaired liver function, this is attributable to the known increase in hepatic clearances in burns patients and, to a certain extent, to the existence of translesional extra-hepatic clearance, which could contribute to the success of treatment.

[Therapeutic monitoring of teicoplanin in a severely burned patient]

The authors report the study of the kinetics in serum and urine and the clinical safety of a high dose of teicoplanin administered in a 19 year-old patient with major burns (60% of body surface area, the half of which consisting of third-degree burns and UBS at 150) and S aureus meticillin-resistant infection. At day 1, he was given two loading infusions of 12 mg.kg-1 teicoplanin followed by 12 mg.kg-1 per day of treatment. At all times, Cmin concentrations were below the limit value of 8 mg.mL-1. Therefore the therapeutic regimen was increased on several occasions. On days 5, 8 and 15, Cmin were measured by FPIA. Pharmacokinetic analysis was performed at day 16, (i.e., 20 mg.kg-1) and urine was also collected over at least 12 hours. At day 16, serum and urine samples were assayed by HPLC. Data were analyzed with a noncompartmental method. The duration of treatment was 20 days and no adverse events were noted. Bacteriological tests performed at the end of treatment demonstrated the elimination of the agent responsible over the infection. While pharmacokinetics were not assessed at plateau, Cmin remained very low. Vss was similar to values obtained in healthy subjects while total clearance was increased. This phenomenon was explained by the increase of total clearance and a nonrenal translesional diffusion suggested by the body surface area affected by third-degree burns. Finally, the cost of increasing doses of teicoplanin must be taken in account.

Is the reduced efficacy of morphine in diabetic rats caused by alterations of opiate receptors or of morphine pharmacokinetics?

Because it generally is admitted that neuropathic pain is resistant to opioid analgesia, we investigated the effect of morphine on hyperalgesia in streptozocin-induced diabetes in rats. The antinociceptive effect of morphine (0.5-4 mg/kg i.v.) on mechanical (paw pressure test), thermal (tail immersion test) and chemical (formalin test) hyperalgesia was reduced. To clarify the mechanisms involved in the alteration of morphine analgesia, the binding characteristics of mu and delta receptor agonists and the pharmacokinetics of morphine and its glucuronide metabolites morphine 3-glucuronide and morphine 6-glucuronide were determined. KD and Bmax values for [3H][D-Ala2,(Me)Phe4, Gly(ol)5]enkephalin and [3H][D-Pen2,D-Pen5]enkephalin to cerebral mu and delta opiate receptors were not altered by diabetes. Likewise, the plasma maximal concentration of morphine and metabolites, as well as the area under the curve, did not differ between diabetic and normal rats. Only the total clearance and the apparent volume of distribution of morphine were increased in diabetic rats, which suggests that the diabetes-induced glycosylation of proteins might increase the distribution of morphine in the aqueous compartment. These data indicate that the reduced analgesic effect of morphine caused by diabetes cannot be explained by a decrease in opiate-receptor affinity or density but rather by kinetic alteration of morphine (increase of total clearance and of volume of distribution in comparison with healthy animals).

Influence of pregnancy on the pharmacokinetic behaviour and the transplacental transfer of the piperacillin-tazobactam combination

The safety/acceptability, blood pharmacokinetics and urinary excretion of the piperacillin-tazobactam (PPR-TZB) combination were studied in six patients between 25 1/7 and 31 5/7 weeks of amenorrhea. The combination was given for a materno-fetal infection due to susceptible organisms i.e. 4/0.5 g/6 h. Whenever possible, the trans-placental transfer (TPT) of the combination was assessed in several sub-compartments of the feto-placental unit i.e. maternal blood sample, cord blood, amniotic fluid, placenta tissue and fetal urine. Two series of nine blood samples were scheduled for each patient, i.e. on D1 (first dose) and D3 (at plateau). Samples were assayed by HPLC and data were analyzed by a non-compartmental method. Safety/acceptability of the treatment proved to be good. The kinetic behavior of both beta-lactams appeared to be identical. Evidence was found during pregnancy of an increase in Vss and Cl of the combination. These increases can be linked to a notable decrease in AUCs. The TPT of the combination was significant. Regarding other accessible compartments (i.e. placenta tissue, amniotic fluid and fetal urine), the ratio of PPR-TZB concentrations was invariably about 8. Maternal circulating levels of PPR-TZB were, by 4 h, less than the MIC of target organisms (i.e. < or = 8 micrograms/ml), both on D1 and at steady state. This raises the question of the pertinence of the dosage regimen. Regarding PPR, it is accepted that antibacterial protection is satisfactory when circulating concentrations are kept at a Css (steady state concentration) of the order of 20 micrograms/ml or more. PPR-TZB combination would be administered by continuous infusion i.e. 8 mg/min to obtain 3 h later a Css of more than 20 micrograms/ml. The daily dosage would then be 12/1.5 g instead of 16/2 g, which is also more satisfactory from a pharmaco-economic standpoint. This proposal must be validated in a sufficient number of patients and, could avoid disqualification of the combination PPR-TZB in the treatment of serious infections during certain pathological pregnancies.

[Traceability of drugs derived from blood: regulation and pharmaco-economic implications after 24 months of application in Paris CHU]

Since January 1, 1995, the supply, stockage, dispensing and traceability of Blood Derivative Medicinal Products (BDMP) are subject to pharmaceutical regulations. A review of 24 months' application at Necker-Enfants Malades Hospital is presented and analysed. A distinction is drawn between two categories of BDMP: 1) anti-hemophilia BDMP, factors of plasma or recombinant origin; 2) non-anti-hemophilia BDMP, covering albumin, immunoglobulins (Ig), biological glues and other clotting factors. BDMP are subject to a hospital traceability procedure. In this respect, we have constructed a tryptic nominative model prescription, though dotations are granted for only certain prescription sectors (operating room, ICU) and certain products (biological glues, albumins). A dispensing-administration form is invariably attached to each bottle. Between January 1, 1995 and December 31, 1996, 8225 dispensing procedures for BDMP were recorded, with a total cost of 52,931,586 francs (i.e. 69% anti-hemophilia products v.s. 31% non-antihemophilia products). The Factor VIII market is divided more or less equally between factors of human and recombinant origin. The risk of viral transmission is considered to be virtually nil with recombinant products, despite their being stabilized by human albumin. The traceability rate of anti-hemophilia factors was 100%. Albumin consumption was 182,106 g at a cost of 3,358,250 francs. The following indications were adopted at a Local Medicines Committee: 1) in adults: hypoalbuminemia associated with edema or ascites; 2) in children: digestive disorders leading secondarily to exsudative enteropathy and/or hypoalbuminemia. Consumption of polyvalent Ig was 69,213 g, i.e. 10,856,722 francs. These products were prescribed in accordance with the directives of the Committee for Evaluation and Distribution of Technological Innovations. Consumption of specific Ig and biological glues may seem modest in relation to that of other products. BDMP expenditure appears particularly heavy here (about 26.5 MF/year) but consensual adoption of therapeutic guidelines has enabled rationalization of prescribing conditions with the best possible consideration of benefit/risk vs costs ratios. Traceability and drug safety monitoring procedures are linked to and integrated in the more global concept of Quality Assurance. Since January 1995, several withdrawals of batches have been recorded because of suspicion (or death due to) Creutzfeld-Jakob, or post-donation HIV seroconversion. In this area, the Hospital Pharmacist acts by the establishment in real time of a permanent safety link between the patient, a prescriber, an indication, a product prescribed and the product actually administered.

Influence of acute renal failure on FPIA rapid serum assay of midazolam and its main metabolite

We recently developed a simple and fast assay technique, providing the possibility of monitoring of midazolam (M) during sedation. We compared HPLC vs FPIA for the measurement of the sum M plus alpha 1-hydroxymidazolam (OM), its main and pharmacologically active metabolite, in the serum of sedated ICU patients; this activity referred to as M-like. We identified certain patients in whom M-like activity appeared abnormally high in comparison with HPLC assays. Their common denominators were: long-term sedation with M, and seriously impaired renal function. Further, the conjugates of OM (OMG) accumulated in patients with acute renal failure could contribute to the sedation. We compared the metabolic and analytic behavior of M, OM, and OMG in 2 groups of sedated patients either presenting with normal renal functions (group 1) or with a picture of acute renal failure (group 2). Blood samples were assayed by HPLC and by FPIA and analysis was performed before and after hydrolysis of OMG. Before hydrolysis there was a dramatic accumulation of OMG in the patients of group 2, HPLC vs FPIA results were not different within group 1, while in group 2 the FPIA response exceeded that of HPLC. After hydrolysis, measurement by HPLC was greatly increased in group 2, in each group (vs HPLC) and from one group to another, the FPIA signal (the M-like activity) showed a significant increase. It would be important to take OMG into account as a coprotagonist in sedation whenever circumstances predispose to its accumulation.

Teicoplanin in cardiac surgery: intraoperative pharmacokinetics and concentrations in cardiac and mediastinal tissues

The concentrations of teicoplanin in the sera and mediastinal and heart tissues of 23 patients undergoing cardiac surgery were measured after two regimens of teicoplanin administration. Intraoperative pharmacokinetic parameters were also obtained. Patients were randomized into two groups. Those in group 1 were given teicoplanin at 6 mg x kg(-1) intravenously at the time of induction of anesthesia. Patients in group 2 were given teicoplanin at 12 mg x kg(-1) during the same period. The maximum concentration in serum (71 +/- 20 and 131 +/- 44 mg x l(-1)), the minimum concentration in serum (3.6 +/- 1.3 and 6.8 +/- 2.1 mg x l(-1)), the area under the concentration-time curve (AUC) from 0 to 12 h (108 +/- 20 and 217 +/- 38 microg x h x ml(-1)), and the AUC from 0 h to infinity (154 +/- 36 and 292 +/- 77 microg x h x ml(-1)) were twice as high after 12-mg x kg(-1) injections as after 6-mg x kg(-1) injections. No differences in mean residence time (9.7 +/- 4.9 and 8.4 +/- 2.7 h) or terminal half-life (8.5 +/- 3.8 and 7.5 +/- 2.3 h) were observed. Teicoplanin penetrated mediastinal and heart tissues but not sternal bone, where the antibiotic was detectable in only 1 of 13 patients in group 1 and 2 of 10 patients in group 2. In group 1, 7 of 13 patients had teicoplanin concentrations in tissue that were lower than the MIC for 90% of the strains of potential pathogens tested (MIC90) that cause infection after cardiac surgery. All of the patients in group 2 but one had teicoplanin concentrations in tissue (other than in sternal bone) far in excess of the MIC90 for the potential pathogens. In conclusion, the 12-mg x kg(-1) regimen of teicoplanin is followed by a significant increase in teicoplanin concentrations in heart and mediastinal tissues and should be preferred to the 6-mg x kg(-1) regimen if teicoplanin is selected for antimicrobial prophylaxis in open heart surgery.

Perioperative pharmacokinetics of piperacillin during liver transplantation

There have been few evaluations of the perioperative pharmacokinetics of antibiotics. Piperacillin (PPR) is a widely prescribed ureidopenicillin of established efficacy against enterobacteria and P. aeruginosa. The serum pharmacokinetics and perioperative safety of PPR were evaluated in 8 patients hospitalized for an orthotopic liver transplantation. The subjects were given a 60 mg/kg infusion of PPR once every 8 hours. PPR was assayed by HPLC and data were analyzed by a noncompartmental method. There were no adverse events during surgery. It seems that kinetics of PPR showed no variation during the anhepatic period. However, transplants notably modified the kinetics of PPR in comparison with data previously published in healthy volunteers. Trends were as follows: flattening of Cmax and prolongation of T1/2 (2.2 h vs 0.92 h). This phenomenon seems to be due to a marked increase in V(area) (44.0 1 vs 16.2 1) while C1 were similar. The increase in V(area) is probably the combined results of multiple factors including blood loss, vascular filling, combined prescription of vasoactive drugs, and, obviously, the surgical procedure itself. Concentrations of PPR were after 4 hours below (i.e. 5/8 patients) the MIC of P. aeruginosa (i.e. < or = 16 micrograms/ml). From 6 hours onwards antibacterial cover was insufficient against the majority of enterobacteria (i.e. < or = 8 micrograms/ml). This inadequate protection included the critical anhepatic period. Measured concentrations achieved by the initial dosage regimen were compared to those obtained by simulation using modified dosing pattern in order to ensure circulating levels constantly of 16 micrograms/ml or more. This leads to a suggested modified dosage pattern in which PPR would be given as 1 dose of 60 mg/kg every 4 hours. Under these conditions the expected concentrations should be constantly over 16 micrograms/ml and any risk of systemic accumulation is excluded.

Comparison of high-performance liquid chromatography and polyclonal fluorescence polarization immunoassay for the monitoring of midazolam in the plasma of intensive care unit patients

Midazolam (M) is used as an induction agent for anesthesia. The main metabolite is alpha-hydroxymidazolam (OM), which is pharmacologically active. Use of M for sedation is a recent application, rapidly gaining favor. Monitoring of the level of sedation is fundamental in that an excessive and prolonged effect is associated with the risk of complications. Thus, it was felt both necessary and useful to measure circulating M levels. We compared a high-performance liquid chromatography (HPLC) assay with fluorescence polarization immunoassay (FPIA) for the measurement of M in the serum of 138 sedated patients in the intensive care unit (i.e., 179 samples). Response of the OM was also assessed. The degree of crossover of the metabolite was between 76.8 and 32.7%. The equation of the regression line for sigma HPLC (i.e., the sum M + OM) versus FPIA was TDx = 1.1585 sigma HPLC + 143.42 (R = 0.966). The 95% confidence interval for the slope was 1.1551, 1.1619. The regression slope differed significantly from 1 (p < 0.001) and shows that FPIA measurements overestimated concentrations obtained by HPLC on the order of 19%. The discrepancy between the two techniques was all the more notable when concentrations were > 1,000 ng/ml. The relative selectivity of Abbott industrial reagent in terms of benzodiazepines leads to the identification of what might be called a midazolam-like (M-like) activity covering both M and OM. The development of a global FPIA method for measurement of this M-like activity in sedated patients provides a satisfactory solution to the question raised.

Clinical pharmacokinetics of piperacillin-tazobactam combination in patients with major burns and signs of infection

The pathophysiology associated with major burns is complex and subject to a state of flux. The combination of beta-lactamase inhibitors with powerful penicillins is an interesting and an attractive potential solution to the emergence of bacterial resistance. The kinetics in serum and urine and the clinical safety of a fixed combination of 4 g of piperacillin (PPR) and 0.5 g of tazobactam (TZB) were studied in 10 patients (22 to 50 years old and weighing 45 to 105 kg) with major burns who were infected with Pseudomonas aeruginosa and various entero-bacteria. All of them received additional antimicrobial drugs. Treatment involved one dose every 6 h. The mean body surface area affected by third-degree burns was 30.0% +/- 4.0%. The study took place in accordance with current ethical guidelines. Two series of blood samples were drawn after the first (day 1) and ninth (day 3 at steady state) doses; urine was collected during the same periods. Levels of PPR and TZB in serum and urine were measured by high-pressure liquid chromatography. A noncompartmental method was used for kinetic and graphic analysis of concentration-time pairs. The safety of the treatment was excellent. There was no systemic accumulation of the beta-lactam combination. Residual concentrations measured on days 1 and 3 [mean (standard error of the mean)] were above the MIC for the organism responsible for infection; i.e., C(min)day1 = 26.3 (8.5) and C(min)day3 = 21.0 (9.1) for PPR and C(min)day1 = 1.9 (0.6) and C(min)day3 = 1.4 (0.3) for TZB. There was no statistically significant difference between pharmacokinetic parameters determined for day 1 and day 3. Evidence was found in burn patients, in contrast to healthy subjects, of a marked increase in apparent volumes of distribution, in such a way that the apparent elimination half-lives of the combination were notably prolonged, i.e., 1.8 (0.3) versus 1.5 (0.3) h for PPR in patients and healthy subjects, respectively, and 1.7 (0.3) versus 1.4 (0.3) h for TZB. These findings indicate the possibility of nonrenal translesional diffusion of PPR-TZB in burn patients. The polarity of the association would further support this hypothesis. It has been shown here that the recommended dosage regimen for administration of PPR-TZB must be high in major-burn patients, i.e., 4 g/0.5 g every 6 h. The data obtained provide valuable information, which is suitable for immediate application in everyday clinical practice.

Study of the bioequivalence of two controlled-release formulations of morphine

The management and treatment of chronic pain in cancer patients is a clear priority for practitioners regularly confronted by the situation. This investigation was carried out to evaluate the bioavailability of a recent sustained-release (SR) formulation of morphine sulphate (30 mg), Skenan, consisted of capsules, relative to a recognized product, Moscontin which is a matrix tablet SR form. The bioavailability was carried out on 12 healthy male volunteers who received a single dose (30 mg) of the test (T) and the recognized (R) products in a randomized balanced 2-way crossover design. After dosing, serial blood samples were collected for a period of 24 hours. Morphine and its main metabolites (i.e. glucuronides M6G and M3G) were assayed by high-performance liquid chromatography using a ion-pair formation. Data were analyzed by a noncompartmental method and were compared by ANOVA method and, each subject taken as his own control, by the Wilcoxon T test. Mean bioavailability of the T formulation was greater than that of R. The parametric confidence intervals (90%) of the mean values of the pharmacokinetics characteristics for T:R ratio were in each case without the bioequivalence acceptable ranges of 0.8-1.25 and 0.70-1.43 respectively for AUCs (i.e. AUCo-->24h and AUCo-->infinity) and Cmax, while confidence intervals symmetric of Westlake (CIW90%) was invariably greater than 20%, i.e. 62.8, 71.1 and 39.3% respectively. Further, the test formulation was not found bioequivalent to the reference formulation by Schuirmann's 2 one-sided t-test. These results justify the conclusion of the non-bioequivalence of the two forms at the unit dose of 30 mg. This information must be considered above all as a dosage adjustment tool enabling use of the two forms by application of a correction factor of the order of 15% when prescribing Skenan in comparison with Moscontin. Assessment is needed of the possible clinical consequences of this finding.

[Pharmacokinetics of antibiotics in burn patients]

The pathophysiology associated with major burns is complex and subject to a state of flux (coexistence of pain, infectious diseases, multiple trauma, disturbances of metabolism and acid-base status, etc) which could affect the disposition and the pharmacokinetic behaviour of drugs. In current clinical practice, practitioners often use powerful antimicrobial agents; however, few pharmacokinetic studies are available in burns patients (of the order of 30 studies). Furthermore, the methods used are sometimes questionable. After dealing with the ethical and physiological context in which such research is undertaken, the authors report a review of the pharmacokinetic studies done during the last 15 years. Concerning both aminoglycosides and glycopeptides, no therapeutic recommendations are available (therapeutic schedules). However, in this case, therapeutic monitoring is available and represents a suitable tool to better master their use. In the case of beta-lactam antibiotics and quinolones, more data are available. Some investigations have shown the possibility of translesional diffusion of certain agents in burns (such as gentamicin, piperacillin/tazobactam combination, or fosfomycin). This phenomenon could be a co-factor of success in treatment. Considering the relatively meager pharmacokinetic and pharmacodynamic data available in burns, it is important in the future to refine our knowledge of the distribution and metabolism of drugs in burns patients in order to better master their use. Finally, ethical and methodological considerations need to be taken in account.

[Pharmacokinetics of clofibrate in jaundiced newborn infants at term]

BACKGROUND

Clofibrate (CFB) has been proposed to increase elimination of bilirubin in neonates with hyperbilirubinemia. Nevertheless, its disposition, at this age, remains unknown. The aim of this work was to characterize pharmacokinetics of an oil formulation of CFB in neonates at term with jaundice.

PATIENTS AND METHODS

Two groups (G1 and G2) of eight neonates, presenting with jaundice, entered an open, non randomized and comparative study. Five blood samples were collected over 50 hours following a single oral administration of 100 mg/kg or 50 mg/kg CFB, respectively, in G1 and G2. Serum concentrations of both CFB and clofibric acid (CFA) were measured by HPLC and the pharmacokinetic analysis was made by a non-compartmental method. Data were compared to those obtained in adults receiving 2 g dose of CFB.

RESULTS

Tolerance to the treatment was excellent. Pharmacokinetic profiles were similar in both groups of infants. There was a slow and prolonged formation of CFA whose serum concentrations remained high 50 hours after drug administration. Non-hydrolyzed CFB was found in the blood of three neonates. Elimination of CFA was prolonged corresponding to a terminal half-life (t1/2m) often above 100 hours and sometimes incalculable. MRTo-->50 (h) was similar in both groups (ie 26.2 +/- 2.0 vs 25.5 +/- 1.3, respectively). The decrease of t1/2m was related to the decrease of the clearance of CFA.

CONCLUSIONS

The decrease in CFB's metabolism in newborns is probably the result of at least two concurrent phenomenons: partial hydrolysis of CFA, especially at high doses, and decrease in the hepatic capacity to conjugate the active metabolite. A single oral administration of 50 mg/kg CFB seems to be a suitable schedule.

Disposition of a new rate-controlled formulation of prazosin in the treatment of hypertension during pregnancy: transplacental passage of prazosin

Prazosin (PRZ) in conventional tablet form (P-CT) has the disadvantages of a relatively short terminal half-life, a slight solubility in water and the well-recognized adverse effect of symptomatic orthostatic hypotension. The pharmacokinetic study of a new rate-controlled formulation of prazosin (Prazosin-Gastrointestinal System: P-GS) was performed in 9 pregnant women during the third trimester of pregnancy. Patients had persistent elevation of blood pressure. The subjects gave their informed consent for oral administration of 1 daily dose of 5 mg P-GS at 8 a.m. A first analysis period on day 1 enabled definition of the initial pharmacokinetic behavior of the drug, while the aim of a second was to evaluate its fate at plateau. The clinical course of both mother and fetus was subsequently monitored. This was an open, non-randomized study, each patient serving as her own control. For 3 patients, we aimed to determine the possible transplacental passage of PRZ at delivery. PRZ levels were measured by HPLC and data were analysed by noncompartmental linear pharmacokinetic methods. The data show: (i) P-GS was well tolerated by all patients and there were no significant changes in fetal heart rate during the study. (ii) A significant decrease in diastolic blood pressure was observed after the 36th hour following the first dose of P-GS while a reduction in systolic blood pressure was observed on day 4. (iii) An approximated relative bioavailability (f'P-GS) of 36.5% was calculated. P-GS appears to have a lower bioavailability than P-CT in women of similar gestational age. (iv) Both Cmax and AUC0-->infinity are significantly increased at plateau. Further, terminal half-life is increased with regard to the value determined with P-CT. No accumulation of PRZ was noted at steady-state. (v) P-GS is an example of an oral zero-order absorption product that offers one approach to control and improve the outcome of hypertensive therapy during pregnancy. This treatment could represent an alternative to methyldopa as a first treatment of pregnancy-associated hypertension. (vi) There is a slight transplacental passage of the drug (of the order of 10-20%).

Disposition of ornidazole and its metabolites during pregnancy

The disposition of ornidazole and its two major hydroxylated metabolites was studied in five pregnant women (gestational ages 25 5/7 to 38 4/7 weeks) with either chorioamnionitis or pyelonephritis treated with ceftriaxone 2 g, tobramycin 3 mg/kg body weight and ornidazole 1 g all administered once-daily. Two series of blood samples were obtained, the first on the first day of treatment and the second at steady-state on day 5. Local and systemic tolerability of ornidazole was excellent and patients showed complete remission without premature delivery. There was no evidence of ornidazole accumulation, and the pharmacokinetic parameters were very similar to those seen in healthy subjects. The dosage regimen of ornidazole therefore requires no adjustment during pregnancy. Trough concentrations of ornidazole measured at 24 h post dose were above the MIC of sensitive organisms. Children born to the trial patients showed normal initial development and their growth was normal.

Models for placental transfer studies of drugs

Pregnancy is a specific dynamic state, and the potential usefulness of caring for a disorder in the fetus or the mother is now well established. Previously, pregnant women have been excluded from clinical trials, therefore only a few studies concerning evaluation of the pregestational metabolism or transplacental transfer (TPT) of drugs exist. Questions regarding the TPT of drugs are extensive and complex. For example, does TPT occur at a given gestational age, in the context of a particular type of pathology or when a drug is administered by a certain dosage regimen? If this is the case, what is the rapidity of penetration of the products of conception by the drug (bearing in mind its physicochemical characteristics)? Need harmful adverse effects on the child be feared? Is such penetration desirable, of no consequence, or dangerous? Does the possibility exist of accumulation in the placenta, fetal tissue or amniotic fluid? Should such findings modify the therapeutic regimens of drugs given to expectant mothers? Exchange mechanisms are complicated and models developed in vitro only partially reflect the actual equilibria that exist between mother and fetus. These include: (i) the perfused cotyledon model, which while simple, elegant and inexpensive, offers only a localised, restricted and fixed view of pregnancy; (ii) isolated anatomical fractions that are informative, but which straddle the border between physiology and pharmacology; and (iii) the necessary study, using microsomes, of placental metabolic capacity (enzyme cartography). In vivo study of TPT is based upon various multicompartmental pharmacokinetic models, some of which have been relatively validated in animals. The simplest indicator for the in vivo evaluation of TPT of a drug in the human species is determination of a feto-maternal blood concentration ratio (usually performed at the time of placental separation). However, the usefulness and limitations of this parameter are controversial, and it would seem preferable to associate it with a pharmacokinetic profile of variations in blood concentrations established in the mother. Furthermore, any extrapolation of a single result to fetal and adjacent tissues must be done with the greatest caution. Although, no drug should be used in pregnancy unless there is a clear therapeutic indication, study of the TPT of therapeutically useful agents is essential to the understanding of their metabolism and is a prerequisite to the safe use of medications during pregnancy.

[Therapeutic strategy in anaphylactoid shock during general anesthesia. Etiologic agents and diagnostic evaluation]

In 1983, the risk of developing severe shock during anaesthesia was estimated to be 1 case in 4600 procedures with an associated mortality rate of 6 per cent. The incidence of severe accidents has further increased since this time. This review focuses on the aspects of anaphylactoid shock (AS) in the context of iatrogenic responsibility involving drugs or substances used during anaesthesia or placed in contact with viscera. The elements predictive of anaphylactoid shock are described together with the arguments involved in a biochemical conception and a physiological conception. The authors emphasize the importance of the operative report and anaesthetic sheet to retrospectively establish the chronology of the events and to facilitate the allergologic work-up. The treatment of AS is an emergency. The therapeutic protocol is relatively well defined and, in addition to IV fluids, adrenalin is the drug of choice during the acute phase of AS. The therapeutic approach to certain particular cases is discussed and future therapeutic concepts are proposed. The aetiological agents of AS are discussed together with their respective frequencies in the specific case of the anaphylaxis reaction. Muscle relaxants are the leading cause of anaphylaxis (70 per cent of cases), especially suxamethonium, vecuronium and atracurium (43 per cent, 33 per cent and 6.8 per cent of cases, respectively). Latex present in various materials, especially surgical gloves, has become the most disturbing substance, responsible for 0.5 per cent of AS in 1989 vs 12.5 per cent of cases in 1991. Hypnotic drugs, although very widely used, are much more rarely incriminated.

[Transplacental transport and feto-placental metabolism of drugs: study methods, therapeutic contributions and implications]

Pregnancy is a specific dynamic state and the potential usefulness of caring for a fetal and/or adjacent disorder by treating the mother is now well established. Pregnant women being excluded from the investigational field of clinical trials, only few studies exist concerning evaluation of the pregestational metabolism or transplacental transfer (TPT) of drugs. Questions are extensive and complex. Does TPT occur at a given gestational age (GA), in the context of a particular type of pathology, when a drug is administered by a certain dosage regimen? If this is the case, what is the rapidity of penetration of the products of conception by the drug (bearing in mind its physical-chemical characteristics)? Need harmful adverse effects on the child be feared? Is such penetration desirable, of no consequence or dangerous? Does the possibility exist of accumulation in the placenta, fetal tissue or amniotic fluid? Should such findings modify the therapeutic regimens of drugs given to expectant mothers? After dealing with the ethical and physiological context in which such research is undertaken, the authors review methods for the study of TPT developed both in vitro and in vivo. The current review covers the period between 1972 and 1993. Exchange mechanisms are complicated and models developed in vitro only partially reflect the actual equilibria which develop. These include: 1) the perfused cotyledon model, which while simple, elegant and inexpensive, offers only a localized and fixed view of pregnancy; 2) the necessary study, using microsomes, of placental metabolic capacity (enzyme cartography). In vivo study of TPT is based upon various multicompartmental pharmacokinetic models, some of which have been relatively validated in animals. The simplest indicator for the in vivo evaluation of TPT of a drug in the human species is determination of a feto-maternal blood concentrations ratio (usually performed at the time of separation). The usefulness and limitations of this parameter are controversial, and it would seem preferable to associate it with a kinetic profile of variations in blood concentrations established in the mother. Any extrapolation of a single result to fetal and adjacent tissues must be done with the greatest caution. Study of the TPT of therapeutically useful agents is essential to the understanding of their metabolism and is a prerequisite to the use of medications during pregnancy, bearing in mind that any such use must always be with the greatest care and with extremely well-founded indications.

Treatment of unruptured tubal pregnancy with methotrexate: pharmacokinetic analysis of local versus intramuscular administration

OBJECTIVE

To determine the optimal dose and route of methotrexate (MTX) in the treatment of ectopic pregnancy (EP).

DESIGN

Prospective randomized study.

SETTING

Department of Obstetrics and Gynecology (A. Béclère Public Hospital, Clamart, France, Paris-Sud University).

PATIENTS AND METHODS

Forty-eight patients with unruptured EP clearly visualized by ultrasound were randomly allocated into four groups of treatment (12 patients in each group): group 1, 1 mg/kg injected locally in the ectopic gestational sac and 1 mg/kg by IM administration 48 hours later; group 2, 1 mg/kg locally; group 3, 0.5 mg/kg locally; group 4, 1 mg/kg by IM administration. Inclusion criteria used a pretherapeutic score < or = 12. Blood samples were collected at time 0.25, 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after MTX administration. Pharmacokinetics of MTX plasma levels were measured by fluorescence polarization immunoassay. Kinetic parameters were compared by Wilcoxon test and Mann-Whitney test. Plasma hCG concentrations were assessed on days 2, 5, and 10 and then weekly until they returned to undetectable levels.

RESULTS

Success rate was 12 of 12, 11 of 12, 10 of 12, and 10 of 12 in groups 1, 2, 3, and 4, respectively. Six patients in group 3 required an additional MTX IM injection because of an inadequate decrease of hCG plasma levels. Five patients underwent surgery for abdominal pain or inadequate decrease of hCG. Area under the curve decreased more rapidly after injection in the gestational sac alone than after IM injection and was similar in groups 1 and 2 after local injection and lower in group 3. Terminal half-life and mean residence time remained similar in the four groups. Systemic side effects of MTX therapy occurred in three cases in groups 1 and 4. The regression curve of hCG plasma levels appeared similar in the four groups with a decrease to pretreatment values between days 6 and 8 after an initial rise after MTX was given.

CONCLUSION

Area under the curve found after injection in the ectopic sac may be related to a decrease in bioavailability of MTX that links to trophoblastic cells. Patients in group 3 were clearly undertreated by 0.5 mg/kg MTX and required additional therapy. Residual values of MTX plasma levels were always below the limit of detection of our assay and confirmed that citrovarum factor rescue is unnecessary. Injection of 1 mg/kg of MTX in the ectopic sac appears as effective as systemic (IM) injection with less side effects for the patients.