Intravenous Infusion Administration Research Articles

Drug therapy of primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is a rare but life-threatening disease. Median survival, from the time of diagnosis, is considered to be 2.8 years. However, therapeutic medical advances over the past 2 decades have resulted in significant improvements in quality of life and survival in patients with PPH. Because pulmonary vasoconstriction, endothelial cell proliferation, smooth muscle cell proliferation, and in situ thrombosis contribute to the development of this disease, treatment with vasodilators, anti-proliferative agents, and anticoagulants is recommended.Currently, oral administration of calcium channel antagonists and intravenous infusion of epoprostenol (prostacyclin) are established as treatment of PPH. Epoprostenol has vasoprotective effects including vasodilation, anti-platelet aggregation, and inhibition of smooth muscle cell proliferation. Interestingly, prostacyclin synthase deficiency in the lungs, and impaired prostacyclin production, have been linked to the development of pulmonary hypertension in this disease. As a result, continuous intravenous infusion of epoprostenol has become recognized as a therapeutic breakthrough that can improve hemodynamics and survival in patients with PPH. The dramatic success of long-term intravenous prostacyclin is now leading to the development of epoprostenol analogs using newer drug delivery systems (oral beraprost, aerosolized iloprost, and subcutaneous treprostinil). In addition, promising drugs including endothelin antagonists and type V phosphodiesterase inhibitors have recently been developed. Furthermore, gene therapy with endothelial nitric oxide synthase gene or prostacyclin synthase gene may hold great promise in the treatment of PPH. Finally, accurate evaluation of disease severity and the efficacy of vasodilator therapy are important in the management of patients with PPH. In addition to invasive assessment by cardiac catheterization, we recommend repeated measurements of plasma brain natriuretic peptide, serum uric acid, and the distance walked in 6 minutes. These noninvasive parameters may be helpful as part of the evaluation of treatment in patients with PPH and, in particular, as a guide to the selection and timing for alternative therapies.

Differential mechanism and site of action of CCK on the pancreatic secretion and growth in rats.

Recent studies demonstrated that cholecystokinin (CCK) at physiological levels stimulates pancreatic enzyme secretion via a capsaicin-sensitive afferent vagal pathway. This study examined whether chemical ablation of afferent vagal fibers influences pancreatic growth and secretion in rats. Bilateral subdiaphragmatic vagal trunks were exposed, and capsaicin solution was applied. Pancreatic wet weight and pancreatic secretion and growth in response to endogenous and exogenous CCK were examined 7 days after capsaicin treatment. Perivagal application of capsaicin increased plasma CCK levels and significantly increased pancreatic wet weight compared with those in the control rats. Oral administration of CCK-1 receptor antagonist loxiglumide prevented the increase in pancreatic wet weight after capsaicin treatment. In addition, continuous intraduodenal infusion of trypsin prevented the increase in plasma CCK levels and pancreatic wet weight after capsaicin treatment. There were no significant differences in the expression levels of CCK-1 receptor mRNA and protein in the pancreas in capsaicin-treated and control rats. Intraduodenal administration of camostat or intravenous infusion of CCK-8 stimulated pancreatic secretion in control rats but not in capsaicin-treated rats. In contrast, repeated oral administrations of camostat or intraperitoneal injections of CCK-8 significantly increased pancreatic wet weight in both capsaicin-treated and control rats. Present results suggest that perivagal application of capsaicin stimulates pancreatic growth via an increase in endogenous CCK and that exogenous and endogenous CCK stimulate pancreatic growth not via vagal afferent fibers but directly in rats.

Pharmacodynamics of Intravenous and Oral Midazolam in Preterm Infants

The aim of this study was to evaluate the pharmacodynamics and safety of midazolam after intravenous infusion or oral administration in preterm infants. METHODS ]PATIENTS WERE RANDOMLY ASSIGNED TO INITIALLY RECEIVE MIDAZOLAM 0.1 MG/KG AS A 30-MINUTE INTRAVENOUS INFUSION OR AN ORAL BOLUS DOSE. IF PATIENTS STILL MET THE INCLUSION CRITERIA, THEY THEN RECEIVED MIDAZOLAM VIA THE ALTERNATE ROUTE (AFTER AN INTERVAL OF ≥72 HOURS). PHARMACODYNAMIC MEASUREMENTS CONSISTED OF A COMFORT® SCORE (A PREVIOUSLY VALIDATED SEDATION SCALE FOR PAEDIATRIC PATIENTS) AT BASELINE AND AT 0.5, 1, 2, 4 AND 6 HOURS POSTDOSE. MIDAZOLAM AND 1-OH-MIDAZOLAM CONCENTRATIONS WERE MEASURED AND VITAL SIGNS WERE RECORDED AT ALL PHARMACODYNAMIC MEASUREMENT TIMEPOINTS: A total of 24 infants were enrolled of whom seven received both intravenous and oral midazolam, 13 received only intravenous midazolam, and four received only oral midazolam. Overall, mean COMFORT® scores decreased (i.e. sedation increased) significantly within 30 minutes after intravenous (p S 0.05) and within 1 hour after oral (p = 0.003) midazolam administration. In 45% of patients the COMFORT® scores decreased little or not at all after midazolam, which was similar after both oral and intravenous administration. The sedative response to midazolam did not differ after intravenous or oral administration. No relationship was found between overall COMFORT® scores or change in COMFORT® score from baseline and midazolam, 1-OH-midazolam, or midazolam plus 1-OH-midazolam concentrations. Diastolic blood pressure decreased significantly after intravenous (approximately 11%) but not after oral midazolam administration. No serious adverse events were reported. Midazolam administered as a 30-minute intravenous infusion or oral bolus dose appears to be effective and well tolerated in a small majority of preterm infants. However, a considerable number of neonates do not appear to respond to midazolam. The lack of response may be due to the fact that patients truly experienced therapeutic failure and/or consequent to the inability of the COMFORT® score to adequately reflect sedation uniformly in sick preterm infants.

Guillain-Barré syndrome and hyponatraemia.

Hyponatraemia is a recognized association of the Guillain-Barré syndrome (GBS) and is also known to occur after the administration of intravenous infusion of gamma globulin (IVIG), a treatment often used in management of GBS. To document serum sodium concentration in GBS patients before, during and after management procedures (including IVIG) positive pressure ventilation (PPV) and the use of medications capable of causing a low serum sodium. To consider whether pseudohyponatraemia might be a contributory factor. To assess whether hyponatraemia is a predictor of poor outcome. Clinical record audit of 84 patients with GBS admitted to Christchurch Hospital, New Zealand, over a 10-year period. Serum sodium concentration was significantly low (<133 mmol/L) in 26 of 84 (31%) patients. In 12 of these cases the hyponatraemia developed during or after IVIG, suggesting that pseudo-hyponatraemia was a contributing factor. Six (7%) significantly hyponatraemic patients died, but no eunatraemic or slightly hyponatraemic patient died (P = 0.001). Six of 38 patients aged > or =50 years died, whereas none of the 46 patients aged <50 years died (P = 0.007). Five of 19 ventilated patients died but only one of 65 non-ventilated died (P = 0.002). Significant hyponatraemia occurred in 26 (31%) of the patients, but in 12 of these it appeared likely that pseudohyponatraemia caused by IVIG was a contributing factor. Hyponatraemic patients have a poorer prognosis than eunatraemic patients, however it is difficult to separate this factor from other poor prognostic factors (older age and PPV).

Pharmacological profile of hydroxy fasudil as a selective rho kinase inhibitor on ischemic brain damage

The neuroprotective property and the effects on hemodynamics of hydroxy fasudil, an active metabolite of an antispastic drug, fasudil, were examined. In rats, hydroxy fasudil was found following intravenous infusion or intraperitoneal administration of fasudil, and the maximum plasma concentration of hydroxy fasudil was approximately 25 or 40% of the parent drug, respectively. The i.v. administration of hydroxy fasudil produced significant increases in regional cerebral blood flow in dogs. Hydroxy fasudil relaxed the KCl, PGF 2 α or U-46619-induced contraction in canine basilar or middle cerebral arterial strips, concentration-dependently. The neuroprotective property of hydroxy fasudil was examined on delayed neuronal death in gerbils. Hydroxy fasudil (3 mg/kg) significantly protected against the ischemia-induced neuronal loss. To further clarify the effect on neurological impairments, hydroxy fasudil was tested in a rat model of microembolization stroke. Intravenous administration of hydroxy fasudil improved neurological functions, significantly reduced the size of the infarct area and prevented the accumulation of neutrophils. The present findings suggest that hydroxy fasudil has an efficacy to improve the hemodynamic function and to inhibit neutrophil-mediated damage, and contributes to the potency and long duration of the cytoprotective properties of fasudil on ischemic brain damage, and also suggest a critical role for rho kinase in the pathogenesis of cerebral ischemic injury, and the potential utility of rho kinase inhibitor as a therapeutic agent in stroke.

Bioavailability and Pharmacokinetic Features of Etoposide in Childhood Acute Lymphoblastic Leukemia Patients

The bioavailability and pharmacokinetic characteristics of etoposide were studied in 12 relapsed B-lineage acute lymphoblastic leukemia (ALL) patients after both intravenous (i.v.) infusion and oral administration. Following a 1 hour i.v. infusion of SO mg/m2 etoposide, the elimination half-life ranged from 49.8 min to 509.4 min (mean ± SD = 218.6 ± 134.7 min), the MRT ranged from 71.8 to 734.9 min (mean ± SD = 315.4 ± 194.3 min) and the systemic clearance of etoposide ranged from 15.7 to 38.0 ml/min/m2 (mean ± SD = 24.1 ± 7.0 ml/min/m2). The AUC ranged from 2234.9 to 5427.0 μM±min) (mean ± SD = 3827.8 ± 1069.5 μM±min) and Vc ranged from 2026.9 to 13505.2 rnl/m2 (mean ± SD = 6825.4 ± 3278.5 ml/m2). The maximum plasma etoposide levels ranged from 6.0 to 28.4 μM (mean ± SD = 13.6 ± 6.3 μM). The bioavailability of oral etoposide was determined by comparing the AUC following i.v. infusion to the AUC following oral administration in the same patient. The overall bioavailability (mean ± SD) was 60.6 ± 22.4% (ranged from 17.6% to 91.2%). The elimination half-life following oral administration (mean ± SD) was 209.8 ± 196.3 min (ranged from 51.0 to 794.2 min). The time required to reach the maximum plasma etoposide concentration was 145.4 ± 118.7 min (ranged from 23.7 to 396.9 min). To our knowledge, this is the first report concerning the bioavailability of etoposide in pediatric leukemia patients. All of the other pharmacokinetic properties of etoposide in pediatric B-lineage ALL leukemia patients reported here were similar to those described previously.

In vivo cerebral pharmacokinetics and pharmacodynamics of diazepam and midazolam after short intravenous infusion administration in sheep.

The cerebral pharmacokinetics and pharmacodynamics of midazolam and diazepam were examined in chronically instrumented sheep via measurements of their arterio-venous concentration difference across the brain during and after 2-min i.v. infusions. Diazepam (30 mg) or midazolam (10 mg) were administered on 5 separate occasions to 4 sheep. For both drugs, rapid cerebral uptake occurred during the infusion, which quickly turned to elution in the postinfusion period. However, this process was more rapid for midazolam than diazepam. The cerebral pharmacokinetics of both was better described by a kinetic model with slight membrane limitation rather than flow limitation. For diazepam, the estimated brain:plasma partition coefficient was 2.67, and the first and second compartments filled with half-lives of 2.2 and 0.5 min, respectively. For midazolam, these values were 0.27, 0.26 and 1.34 min, respectively. In a subset of sheep, pulmonary arterial-arterial gradients were too small to measure suggesting limited metabolism and small distribution volumes for both drugs in the lungs. Simultaneous dynamic measurements of cerebral blood flow and algesimetry lagged behind both the arterial and sagittal sinus blood concentrations. The changes in cerebral blood flow were best described by a previously published a dynamic model that incorporated long half-lives for drug dissociation from the benzodiazepine receptor (13.3 and 5.5 min for midazolam and diazepam, respectively). Effect compartment modeling of the cerebral blood flow data showed apparent effect compartment half-lives (t1/2,keo) that were longer than the half-lives of cerebral equilibration.

The Role of Genetics in Inhibitor Formation

Previous studies in humans and animal models, as well as the analysis of data collected for this study, appear to strongly support the role of genetic factors in the formation of inhibitors, in addition to the specific underlying factor VIII mutation. The elucidation of novel genes important to inhibitor development has the potential to lead to improved understanding of the pathogenic mechanisms underlying this immune response in humans and, ultimately, to the development of new approaches to prevention or treatment of this serious complication of hemophilia.

Pharmacokinetics of ITF 296 (Sinitrodil) a novel organic nitrate, in healthy volunteers

ITF 296 is a new orally active nitrate acting selectively on large arterial vessels over a wide range of doses. In healthy volunteers it causes less reduction in vascular resistance and less venodilatation than classic nitrates. Its pharmacokinetic profile was evaluated after intravenous infusion and oral (solution and immediate-release tablet) administration in a randomised cross-over design on 11 healthy volunteers. The plasma levels of ITF 296 and its metabolite ITF 1124 were determined by a HPLC method. The drug is rapidly distributed (mean steady-state distribution volume 53±17 liters) and eliminated (half-life of about 25 minutes) both after intravenous and oral administration. The total clearance is 2.31±0.46 l/min. The oral solution of ITF 296 is well absorbed ( C max=0.057 μg/ml, t max=30 min) but it undergoes a first-pass effect ( F=25%). The tablet, developed only for Phase 1 clinical studies, is characterised by an immediate release ( C max=0.057 μg/ml, t max=30 min). The extent of its absolute and relative bioavailability is about 14% and 53% respectively.

Aldesleukin (Recombinant Interleukin-2)

Aldesleukin [recombinant interleukin-2 (IL-2)] is a biological response modifier which, like endogenous IL-2, has a range of immunomodulatory properties. Although aldesleukin is currently approved only for treatment of renal cell carcinoma, it has been widely used in patients with metastatic melanoma and has been assessed in numerous noncomparative trials in this indication. Durable complete responses have been reported in a small proportion of patients with good performance status who received immunotherapy or chemoimmunotherapy involving aldesleukin in several clinical trials. Overall median survival times of about 10 or 11 months are typical. Combination chemoimmunotherapy involving aldesleukin has produced relatively high response rates (up to 56%), but these are not predictive of increased survival time. Aldesleukin has not been directly compared with standard chemotherapy in randomised studies. The use of continuous intravenous infusion and subcutaneous administration of aldesleukin, together with improved patient selection, has successfully reduced the severity of adverse events produced by the drug (the original intravenous bolus regimen is particularly toxic and often necessitates admission to an intensive care unit). However, the risk/benefit profile of aldesleukin in the treatment of melanoma requires further study, particularly after subcutaneous administration. Thus, aldesleukin has shown modest efficacy in the treatment of metastatic melanoma. Although aldesleukin-containing regimens have produced promising results in many noncomparative trials, their clinical value in comparison with standard chemotherapy remains to be determined in phase III studies. Until results from such trials are available, clinicians will need to carefully balance the potential benefits of the drug against the risks and likely quality-of-life implications associated with its toxicity in each patient. Current investigations centre on the use of aldesleukin as part of complex biochemotherapy regimens, and results from these trials are awaited with interest.

Effects of oral vs. i.v. glucose administration on splanchnic and extrasplanchnic O2 uptake and blood flow.

The metabolic and circulatory responses to intravenous or oral administration of glucose (75 g) were studied in healthy subjects. Pulmonary oxygen uptake increased promptly after oral but not during intravenous glucose infusion. The average 2-h rise above basal in whole body oxygen uptake was 8 +/- 1% (P < 0.001) after oral glucose and 3 +/- 1% (P < 0.05) during intravenous glucose infusion. After oral glucose, splanchnic oxygen uptake rose initially by approximately 15% (P < 0.01) and then declined; its average 2-h postprandial level was not significantly higher than that in the basal state. During intravenous glucose, splanchnic oxygen uptake decreased gradually during the first 75 min, reaching a level approximately 25% below basal (P < 0.05). Oxygen consumption by extrasplanchnic tissues rose significantly and to a similar extent (8%, 2 h average) with both intravenous and oral glucose. Splanchnic blood flow increased significantly after oral but not during intravenous glucose. It is concluded that 1) intravenous infusion and oral glucose administration elicit extrasplanchnic thermogenic effects of similar magnitude, 2) during intravenous glucose infusion, the extrasplanchnic thermogenic effect is counterbalanced by a simultaneous reduction in splanchnic oxygen uptake, resulting in a minimal (3%) net rise in whole body oxygen uptake, and 3) oral glucose ingestion but not intravenous glucose infusion increases the splanchnic blood flow.

High-performance liquid chromatographic analysis of ( S)- α-amino-5-phosphonomethyl[1,1′-biphenyl]-3-propanoic acid (EAB 515) in brain and blood microdialysate (on-line) and in plasma ultrafiltrate of freely moving rats

( S)- α-Amino-5-phosphonomethyl[1,1′-biphenyl]-3-propanoic acid (EAB 515, I), a competitive antagonist of the N-methyl- d-aspartate receptor, has significant pharmacological activity in the central nervous system (CNS). An extremely sensitive and selective analytical method was developed for the simultaneous analysis of I and its hydroxylated analog (RDC, II) in the microdialysate (MD) and plasma ultrafiltrate (UF) of rats. Microdialysis was used for in vivo sampling of unbound drug in the CSF, cortical extracellular fluid and in the blood of freely moving rats. Compound II was used for retrodialysis-based in vivo calibration of microdialysis probes to estimate the recovery of I. Compound I, being extremely hydrophilic with a high degree of ionization at the physiological pH of 7.4, has limited access to the brain regions. This, combined with its low microdialysis recovery, made the estimation of low brain concentrations of I a challenge. The analytes in MD and UF were separated (within 5 min) by reversed-phase HPLC on a 250×4.6 mm I.D. Maxsil 5 μm RP-2 column, and fluorescence of the eluent was monitored at 255 nm ( λ ex) and 320 nm ( λ em). A 0.09% (v/v) aqueous solution of trifluoroacetic acid (1 ml/min) was used as the mobile phase. The response for I in MD and UF samples was linear from 5 to 2000 ng/ml and from 20 to 10 000 ng/ml, respectively. The between-run ( n=6) and within-run ( n=3) variability of the assay was <15%. Plasma-protein binding of I ( f u=0.68) was determined to be linear from 0.1 to 10 μg/ml. The analytical sensitivity, precision and accuracy of this method was suitable for the characterization of the pharmacokinetics and the CNS distribution of I, following administration of intravenous (i.v.) infusion, single i.v. bolus and multiple i.v. bolus doses of I to freely moving rats, with continuous microdialysate sampling of multiple tissues and simultaneous on-line HPLC analysis. Pharmacokinetic parameters for I, as determined from concentrations in blood MD samples with on-line analysis, were in good agreement with those estimated from concentrations in the UF of plasma samples obtained by conventional sampling.

Pharmacokinetics of Moxisylyte in Healthy Volunteers After Intravenous Infusion and Intracavernous Administration With and Without a Penile Tourniquet

The concentration-time profiles of metabolites of moxisylyte (or thymoxamine), an alpha-blocking agent, were investigated in 18 healthy volunteers after intravenous (i.v.) and intracavernous (i.c.) administrations with and without a tourniquet. Four metabolites, unconjugated desacetylmoxisylyte (DAM), DAM glucuronide, and DAM and monodesmethylated DAM (MDAM) sulfates, were found in plasma and urine. For all metabolites, tmax was significantly increased after i.c. administrations and Cmax was significantly decreased. Maximum plasma level of unconjugated DAM was lower after i.c. administration with (1.81-fold) and without (1.26-fold) a tourniquet than after i.v. administration (43.6 +/- 19.6 ng/ml). The elimination half-life of each metabolite showed no change between the three treatments. The difference of 19 min between the mean residence times of unconjugated DAM after i.c. administration with and without a tourniquet may be compared with the difference between the mean duration of the intumescence, that is, 19 min (73 and 54 min with and without a tourniquet, respectively). Total percentages of metabolites recovered in urine were 66.2 +/- 20.9, 61.4 +/- 12.2, and 58.7 +/- 9.1% after i.v. and i.c. administrations with and without a tourniquet, respectively. In conclusion, tourniquet placed before i.c. administration increased the mean residence time of unconjugated DAM of approximately 25% and seemed to increase the efficacy of the drug in healthy volunteers.

Dose-escalating pharmacokinetics of AZT-P-DDI (IVX-E-59) after short-term intravenous infusion and oral administration in HIV-infected patients.

Dose-escalating pharmacokinetics of AZT-P-DDI (IVX-E-59) after short-term intravenous infusion and oral administration in HIV-infected patients.

The extraction of diethylhexylphthalate (DEHP) from polyvinyl chloride components of intravenous infusion containers and administration sets by paclitaxel injection

Paclitaxel injection (Taxol TM) contains cremophor and ethanol in equal proportions, two agents known to leach diethylhexylphthalate (DEHP) from polyvinyl chloride (PVC) infusion bags and administration sets. The manufacturers of paclitaxel therefore recommend the use of glass, polypropylene or polyolefin containers for storage. This recommendation poses a number of practical problems since the availability of these other types of containers is severely limited and as such staff may be unfamiliar in their handling. The aim of this study was to investigate the extent of DEHP extraction by paclitaxel injection contained in PVC infusion bags and administered by either PVC or non-PVC sets in a bid to verify the manufacturers' recommendations to avoid using PVC containers. The results indicated that during a 3 h infusion period, increasing amounts of DEHP were leached into the paclitaxel vehicle from both the PVC infusion bags and the standard PVC sets. The amounts of DEHP extracted depended on the concentration of the paclitaxel vehicle, the length of contact between the injection vehicle and the container and the type of administration set used. DEHP concentration was at its lowest when a non-PVC set was used to administer the infusate. The addition of 300 and 600 mg paclitaxel to the infusate, administered by non-PVC sets, led to no significant increase in DEHP extraction. Comparative total amounts of DEHP extracted for each dose were 10.0 and 30.3 mg for the paclitaxel vehicle infusion through non-PVC sets and 13 and 30.5 mg respectively for the formulated drug plus vehicle. These amounts of DEHP are substantially less than those delivered during a blood transfusion. Furthermore, the possibility of chronic exposure to DEHP from paclitaxel administered under these conditions is negligible in patients receiving the drug on four to six occasions. The study concludes that there is only minimal risk of DEHP exposure from paclitaxel infusion contained in PVC bags and administered through non-PVC administration sets.

Efficacy of constant infusion of A-77003, an inhibitor of the human immunodeficiency virus type 1 (HIV-1) protease, in limiting acute HIV-1 infection in vitro

A-77003, a human immunodeficiency virus type 1 (HIV-1) protease inhibitor, is effective for both acute and chronic infection in vitro and was evaluated clinically by continuous intravenous infusion administration. The minimum effective dose (the concentration required to completely inhibit viral replication) was determined in vitro in a population of uninfected (99%) and HIV-infected (1%) cells exposed to A-77003 by continuous infusion in hollow-fiber bioreactors. The production of infectious HIV and release of p24 antigen from infected cells were completely inhibited in cultures exposed to A-77003 at or above a concentration of 0.5 microM. Measurement of unintegrated HIV-1 DNA synthesis and flow cytometric analysis for cells expressing HIV p24 antigen demonstrated that the spread of HIV to uninfected cells was also blocked at 0.5 microM A-77003. Dose deescalation to 0.25 microM or removal of A-77003 resulted in the limited spread of the virus throughout the culture, the resumption of viral DNA synthesis, and release of p24. HIV produced after exposure to 0.5 microM A-77003 was noninfectious for a period of 72 h after the removal of the drug. Addition of 1 mg of alpha 1-acid glycoprotein per ml to this in vitro system completely ablated the anti-HIV effect of 0.5 microM A-77003. These data suggest that determination of the minimum effective dose under conditions which simulate human pharmacodynamic patterns may be useful in determining the initial dose and schedule for clinical trials. However, other factors, such as serum protein binding, may influence the selection of a therapeutic regimen.

Disposition and bioavailability of the β1‐adrenoceptor antagonist talinolol in man

In an open randomized crossover study, the pharmacokinetics and bioavailability of the selective beta 1-adrenoceptor antagonist talinolol (Cordanum--Arzneimittelwerk Dresden GmbH, Germany) were investigated in twelve healthy volunteers (five female, seven male; three poor and nine extensive metabolizers of the debrisoquine hydroxylation phenotype) after intravenous infusion (30 mg) and oral administration (50 mg), respectively. Concentrations of talinolol and its metabolites were measured in serum and urine by HPLC or GC-MS. At the end of infusion a peak serum concentration (Cmax) of 631 +/- 95 ng mL-1 (mean +/- SD) was observed. The area under the serum concentration-time curve from zero to infinity (AUC0-infinity) was 1433 +/- 153 ng h mL-1. The following parameters were estimated: terminal elimination half life (t 1/2), 10.6 +/- 3.3 h; mean residence time, 11.6 +/- 3.1 h; volume of distribution, 3.3 +/- 0.5 L kg-1; and total body clearance, 4.9 +/- 0.6 mL min-1 kg-1. Within 36 h 52.8 +/- 10.6% of the administered dose was recovered as unchanged talinolol and 0.33 +/- 0.18% as hydroxylated talinolol metabolites in urine. After oral administration a Cmax of 168 +/- 67 ng mL-1 was reached after 3.2 +/- 0.8 h. The AUC0-infinity was 1321 +/- 382 ng h mL-1. The t 1/2 was 11.9 +/- 2.4 h. 28.1 +/- 6.8% of the dose or 55.0 +/- 11.0% of the bioavailable talinolol was eliminated as unchanged talinolol and 0.26 +/- 0.17% of the dose as hydroxylated metabolites by kidney. The absolute bioavailability of talinolol was 55 +/- 15% (95% confidence interval, 36-69%).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Subcutaneous and Intravenous Administration of Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor for Peripheral Blood Stem Cell Mobilization

In an effort to determine whether subcutaneous or continuous intravenous infusion administration of rhGM-CSF results in better hematopoietic progenitor mobilization, the findings of two sequential clinical trials were reviewed. Patients who had received prior chemotherapy for leukemia, lymphoma, multiple myeloma, breast cancer, or other solid tumors and were candidates for high-dose therapy received rhGM-CSF, 250 micrograms/m2/day, either as a continuous intravenous infusion (trial 1) or subcutaneously (trial 2) for stem cell mobilization. At least five apheresis collection procedures were performed to collect a target number of 6.5 x 10(8) mononuclear cells (MNC)/kg. For the 37 patients in trial 1, the collections contained a median of 7.99 x 10(8) MNC/L (range 6.42-21.36) and a median of 5.27 x 10(4) CFU-GM/kg (range 0.28-19.35). In trial 1, 25 patients were autografted with their cells and recovered 0.5 x 10(9) granulocytes/L at a median of 12 days (range 6-16). For the 33 patients in trial 2, the autograft product contained a median of 7.63 x 10(8) MNC/kg (range 6.51-22.66) and 6.31 x 10(4) CFU-GM/kg (range 0.06-60.4). In trial 2, 25 patients were autografted. The median time to reach 0.5 x 10(9) granulocytes/L was 11 days (range 9-26). All patients received rhGM-CSF after peripheral stem cell transplant. No significant differences in the collected products or the time to hematopoietic recovery was found between the two trials (p > 0.05). The mobilization effects of subcutaneous rhGM-CSF in these pretreated patients were similar to those of intravenous rhGM-CSF.

Population pharmacokinetics of hydroxyurea in cancer patients

The pharmacokinetics of hydroxyurea (HU) were investigated in cancer patients after intravenous infusion or oral administration. On the basis of the minimal value of the objective function (MVOF) and prior knowledge of the disposition of HU in animals and man, the data were best described by a one-compartment pharmacokinetic model with parallel Michaelis-Menten metabolism and first-order renal excretion. The computer program NONMEM (nonlinear mixed effects model) was used to perform the nonlinear regression and provide estimates of the population parameters. For the combined intravenous and oral data set, these parameters were estimated to be: maximal elimination rate (Vmax), 0.097 mmol h-1 l-1; Michaelis constant for HU elimination (KM), 0.323 mmol/l; renal clearance (ClR), 90.8 ml/min; volume of distribution (Vd), 0.186 x (body weight) + 25.4 l; absorption rate constant (Ka), 2.92 h-1; and availability to the systemic circulation (F), 0.792. The principal findings of the investigation are that HU undergoes nonlinear elimination in cancer patients and that HU is reasonably well absorbed following oral administration.

Sequential administration of recombinant human interleukin-3 and granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for malignant lymphoma: a phase I/II multicenter study

Preclinical studies of recombinant human interleukin-3 (rhIL-3) and granulocyte-macrophage colony-stimulating factor (rhGM-CSF) have shown enhancement of multilineage hematopoiesis when administered sequentially. This study was designed to evaluate the safety, tolerability, and biologic effects of sequential administration of rhIL- 3 and rhGM-CSF after marrow ablative cytotoxic therapy and autologous bone marrow transplantation (ABMT) for patients with malignant lymphoma. Thirty-seven patients (20 patients with non-Hodgkin's lymphoma and 17 patients with Hodgkin's disease) received one of four different treatment regimens before ABMT. Patients were entered in one of four study groups to receive rhIL-3 (2.5 or 5.0 micrograms/kg/day) administered by subcutaneous injection for either 5 or 10 days starting 4 hours after the marrow infusion. Twenty-four hours after the last dose of rhIL-3, rhGM-CSF (250 micrograms/m2/d as a 2-hour intravenous infusion) administration was initiated. rhGM-CSF was administered daily until the absolute neutrophil count (ANC) was &gt; or = 1,500/microL for 3 consecutive days or until day 27 posttransplant. The most frequent adverse events in the trial included nausea, fever, diarrhea, mucositis, vomiting, rash, edema, chills, abdominal pain, and tachycardia. Three patients were removed from the study because of chest, skeletal, and abdominal pain felt to be probably related to study drug. Four patients died during the study period because of complications unrelated to either rhIL-3 or rhGM-CSF. The median time to recovery of neutrophils (ANC &gt; or = 500/microL) and platelets (platelet count &gt; or = 20,000/microL) was 14 and 15 days, respectively. There were fewer days of platelet transfusions than seen in historical control groups using rhGM-CSF, rhG-CSF, or rhIL-3 alone. In addition, there were fewer days of red blood cell transfusions compared with historical controls using no cytokines or rhGM-CSF. These data indicate that the sequential administration of rhIL-3 and rhGM-CSF after ABMT is safe and generally well-tolerated and results in rapid recovery of multilineage hematopoiesis.