Determination of the newer quinolones levofloxacin and moxifloxacin in plasma by high-performance liquid chromatography with fluorescence detection.

A simple, accurate, sensitive, and precise reversed-phase (RP) high-performance liquid chromatographic (HPLC) method with fluorescence detection allowing the sensitive and specific quantitation of the newer fluoroquinolones levofloxacin and moxifloxacin is described. Moxifloxacin is used as the internal standard for the determination of levofloxacin and vice versa. A single-step liquid-liquid extraction from human plasma is sufficient for both quinolones. The method is linear from 0.1 to 15 microg/mL and 0.2 to 7 microg/mL for levofloxacin and moxifloxacin, respectively, covering the clinically relevant plasma concentration range. The limits of quantitation are 0.05 microg/mL (levofloxacin) and 0.2 microg/mL (moxifloxacin). The method is successfully applied to plasma drug level monitoring in a volunteer receiving single therapeutic doses of levofloxacin or moxifloxacin at two different occasions.

Effect of three months' treatment with irbesartan on blood and pulse pressure of hypertensive type 2 diabetic patients: open, observational study in 31,793 patients.

OBJECTIVES: In hypertensive diabetics the cardiovascular risk is substantially increased. Therefore, an effective reduction of both blood pressure and pulse pressure is of particular importance for these patients. The aim of the prospective observational study in hypertensive type 2 diabetics was to assess the effect of a switch from the previous antihypertensive therapy to the angiotensin-II-receptor antagonist irbesartan (alone or in combination with HCTZ) on the reduction of blood pressure and pulse pressure, the reduction of diabetic nephropathy (microalbuminuria), and tolerability. METHODS: 8714 general practitioners included 31,793 type 2 diabetics aged at least 18 years in an open observational study. After inclusion in to the study the patients received irbesartan 300 mg as monotherapy or in combination with hydrochlorothiazide 12.5 mg (HCTZ). Main outcome measures for efficacy were the reduction of systolic (SBP) and diastolic (DBP) blood pressures, reduction of pulse pressure, and blood pressure responder (reduction in DBP > or = 10 mmHg or diastolic < 90 mmHg), diastolic normalization (DBP < 90 mmHg) and overall normalization rates (SBP < 140 mmHg and DBP < 90 mmHg) after 3 months. Further outcome measures included the reduction of microalbuminuria or proteinuria, and adverse events (AEs) as a measure of tolerability. RESULTS: Thirty-eight per cent of patients received irbesartan 300 mg and 61% irbesartan in combination with HCTZ. Mean systolic blood pressure was reduced by 22.5 mmHg, diastolic blood pressure by 10.7 mmHg (baseline values: 160.2 and 93.2 mmHg). Pulse pressure fell on average by 11.6 mmHg. 83.4% of the patients were responders, with an overall normalization rate of 42.7% (SBP < 140 mmHg and DBP < 90 mmHg), respectively 73.8% (DBP < 90 mmHg). The antihypertensive benefit was achieved irrespective of the previous medication. Mean albuminuria decreased by about 27.7 mg/L. Only 0.3% of patients experienced adverse events. CONCLUSIONS: In type 2 diabetics with hypertension and either uncontrolled or no previous antihypertensive therapy a change to treatment with irbesartan or irbesartan/HCTZ for 3 months resulted in a distinct reduction of systolic and diastolic blood pressures, with concomitant effective reductions of pulse pressure and microalbuminuria.

One-year safety and quality of life outcomes in patients with atrial fibrillation on dronedarone: prospective, non-interventional study in German ambulatory care.

BACKGROUND AND AIMS: The multichannel blocker dronedarone is currently indicated for the maintenance of sinus rhythm after successful cardioversion in adult clinically stable patients with paroxysmal or persistent atrial fibrillation (AF), with careful monitoring of cardiac, hepatic and renal function. We aimed to investigate patients' quality of life (QoL) and tolerability and effectiveness of dronedarone under real life conditions. METHODS: In the 1-year prospective, non-interventional IMPULS study, 161 office-based cardiologists, general practitioners and internists throughout Germany documented 549 patients with AF who were currently or newly prescribed dronedarone (safety set, SS). Of those, 342 patients (full analysis set, FAS) provided data on QoL at baseline, 6 months and 12 months). RESULTS: Mean age of patients was 67.6/66.3 years; 53.0 %/57.3 % were men (SS/FAS). AF type at inclusion in the SS/FAS was paroxysmal in 71.9 %/71.3 % and persistent in 26.0 %/26.6 % (missing in 2.0 %/2.0 %). The proportion of patients in sinus rhythm increased from 44.6 % at baseline to 70.2 % (SS). The mean value on the 100-point visual analogue scale (EuroQol EQ-5D) increased from 62.3 ± 17.1 at baseline by 11.4 ± 18.7 points (FAS, p<0.0001). The AF-QoL Psychological Domain improved from 44.6 ± 22.6 at baseline by 16.0 ± 23.5 points at 1 year (p<0.0001), the AF-QoL physical domain from 49.5 ± 22.1 by 10.9 ± 22.5 points (p<0.0001), and the AF-QoL sexual domain from 61.8 ± 27.1 by 6.6 ± 28.2 points (p<0.0001). In all, 136 patients (24.8 % of all patients in the safety set) had at least one adverse drug reaction (ADR) causally related to dronedarone. CONCLUSIONS: Various dimensions of quality of life of patients with AF were improved on dronedarone under clinical practice conditions. No previously unknown safety issues were noted.

Indication, outcome and follow up of intensive care in patients with HIV-infection.

BACKGROUND/AIM: The admission to intensive care is controversially discussed in patients with HIV infection, since life expectancy is limited. Therefore, we analyzed indications, outcomes and follow up of all patients with confirmed HIV-infection and Aids defining symptoms who had been admitted to the intensive care unit (ICU) of our department between 1985-1996. RESULTS: 49 patients were admitted to the ICU, 42 of them with CDC stage C of HIV infection before admission. The leading indications were pneumonia (n = 15; PCP: 10, bacterial: 5), acute bleedings (n = 14), acute neurological diseases (n = 6), and gastrointestinal perforation (n = 5). Overall mortality was 39% (19/49) with a higher mortality seen in patients with respiratory disorders (53%) compared to non-respiratory disorders (22%, n.s.). The only significant predictor of mortality was the serum creatinine (p = 0.001), while differences in the APACHE II score between survivors and non-survivors did not reach statistical significance (22 +/- 7, 16 +/- 5; p = 0.14). During follow up no difference was seen in the life expectancy of HIV-infected survivors of intensive care as compared to those patients with AIDS who had never been admitted to ICU (8.4 months versus 9 months). DISCUSSION: The need for intensive care in HIV infected patients does not accelerate the progression of HIV infection to death, if the complications requiring ICU intervention can be managed successfully. Respiratory infections and impaired renal function are risk factors for a fatal outcome. Thus, HIV infected patients benefit from intensive care therapy.

Labelling studies for structure elucidation of a new hydroxymetabolite of tramadol.

Abstract Tramadol, racemic 1-(3-methoxyphenyl)-2-(dimethylaminomethyl)cyclohexane-1-ol, is an effective analgesic drug. Metabolites of tramadol described so far originate from O- and N-demethylation and are excreted in urine directly or after conjugation. A further metabolite was found in human liver microsome incubations and in the urine of volunteers after ingestion of tramadol. To elucidate the structure of the new metabolite, seven deuterated isotopomers of tramadol have been synthesized and ingested by volunteers. The mass spectra of the metabolites derived showed (i) that it was a hydroxy metabolite, (ii) that the hydroxy group was not located on the aromatic ring, the side chain, or the positions 2 and 6 of the cyclohexane ring, (iii) that the hydroxy-group was introduced to one of the the positions 3, 4 or 5 of the cyclohexane ring. The hydroxy metabolite was formed preferentially from the (-)-enantiomer, (1S,2S)-tramadol.

Labelling studies for structure elucidation of a new hydroxymetabolite of tramadol.

Tramadol, racemic 1-(3-methoxyphenyl)-2-(dimethylaminomethyl)cyclohexane-1-ol, is an effective analgesic drug. Metabolites of tramadol described so far originate from O- and N-demethylation and are excreted in urine directly or after conjugation. A further metabolite was found in human liver microsome incubations and in the urine of volunteers after ingestion of tramadol. To elucidate the structure of the new metabolite, seven deuterated isotopomers of tramadol have been synthesized and ingested by volunteers. The mass spectra of the metabolites derived showed (i) that it was a hydroxy metabolite, (ii) that the hydroxy group was not located on the aromatic ring, the side chain, or the positions 2 and 6 of the cyclohexane ring, (iii) that the hydroxy-group was introduced to one of the the positions 3, 4 or 5 of the cyclohexane ring. The hydroxy metabolite was formed preferentially from the (-)-enantiomer, (1S,2S)-tramadol.

[Immunoglobulins--merely expensive or also useful?]. / Immunglobuline--nur teuer oder auch nützlich?

About 15 years ago, treatment with intravenous immune globulin (IVIG) for primary immunodeficiency diseases was introduced. The concept of replacement of deficient circulating antibodies to prevent infections in these patients subsequently proved to be beneficial. Up-to-date IVIG therapy is considered to be the treatment of choice in many primary or secondary immunodeficiency states. The observation of a significant increase in the platelet count in patients with agammaglobulinemia and severe thrombocytopenia after IVIG therapy developed interest in possible modulatory effects of IVIG on the immune system. Although the mode of action of IVIG in autoimmune diseases is not completely understood, therapeutic benefit has been shown in some diseases. It has to be stated that IVIG in autoimmune diseases are rarely first therapeutic choice; however, IVIG might be indicated in patients where conventional and cheaper therapy has failed. This review summarizes the status of IVIG therapy in primary and secondary immunodeficiency states and possible indications in autoimmune diseases.

A global perspective on blood pressure treatment and control in a referred cohort of hypertensive patients.

Hypertensive patients with cardiovascular (CV) comorbidities are at increased risk, and cardiologists' care should put particular emphasis on controlling blood pressure. Data on blood pressure treatment and control and drug utilization on a global scale, however, are scarce. Aiming to resolve this lack of information, the authors analyzed the data of International Survey Evaluating Microalbuminuria Routinely by Cardiologists in Patients With Hypertension (i-SEARCH) to gain further insights into national and regional blood pressure control and antihypertensive pharmacotherapy prescribed in cardiology practice. A total of 22,282 patients with hypertension from 26 countries were enrolled in 2005/2006. A total of 18,652 patients were treated (mean age, 63.0±11.4 years; 52.2% male; mean body mass index, 28.9 kg/m2). Mean systolic blood pressure was 148.2±19.8 mm Hg and diastolic blood pressure was 86.7±11.6 mm Hg. Blood pressure was controlled in 8.3% of diabetic and 25.3% of nondiabetic patients (21.2% overall), with particularly good control rates in North and Latin America (28.0% and 30.6%, respectively). A total of 31.2% of patients were treated with 1, 39.7% with 2, and 29.1% with ≥3 drugs. ß-blockers were being used most frequently (47.9%), in both monotherapy and combination therapy despite low numbers of patients with respective compelling indications for their use. The present data illustrate the potential for an improvement of blood pressure treatment and control in daily cardiology practice.

Influence of the angiotensin converting enzyme inhibitor ramipril on high-sensitivity C-reactive protein (hs-CRP) in patients with documented atherosclerosis.

UNLABELLED: Some medications have been shown to produce reductions in hs-CRP levels after initiating therapy. Whereas the role of the renin-angiotensin system in the inflammatory process has been documented in more detail during the last few years, the impact of an ACE-inhibitor therapy on this process has not been fully understood so far. The aim of this study was to investigate the effect of a therapy with the angiotensin-converting enzyme (ACE) inhibitor ramipril on hs-CRP plasma concentrations in patients with atherosclerosis. METHODS AND RESULTS: A total of 24 patients were enrolled in this prospective, uncontrolled, open-label multicenter study. Inclusion criteria were documented atherosclerosis, baseline high-sensitivity C-reactive protein between 3 and 12 mg/l, LDL-Cholesterol < or =150 mg/dl and no previous treatment with ACE inhibitors or angiotensin receptor blockers. Ten patients, pretreated with statins, and 10 patients not previously treated with statins were eligible for statistical analysis. Baseline high-sensitivity C-reactive protein was significantly decreased from 3.99+/-1.61 mg/l (mean+/-SD) to 2.72+/-1.19 mg/l (-32%) after 3 months treatment with 10 mg ramipril daily (p=0.0002). The decrease was more pronounced in patients who had not been treated with statins previously (-1.50 mg/l+/-1.44 mg/l) compared to those who were pretreated (-0.90 mg/l+/-0.93 mg/l). CONCLUSIONS: The ACE inhibitor ramipril administered in a daily dose of 10 mg to patients with atherosclerosis reduces the high-sensitivity C-reactive protein concentration. This effect may contribute to cardiovascular risk reduction mediated by ramipril aside from the blood pressure lowering effect.

Diagnosis of impaired glucose tolerance in hypertensive patients in daily clinical practice.

Many patients with hypertension suffer from impaired glucose tolerance or type 2 diabetes mellitus. Although these diagnoses are generally simple and reliable, it is more difficult to diagnose impaired glucose tolerance. As the gold standard (oral glucose tolerance test (OGTT)) is complicated to perform, a simpler alternative would be useful. The aims of the Pre-Diabetes Score study are to correlate demographic and/or laboratory parameters that are clinically simple to determine with the results of the OGTT and to determine the diagnostic significance of the combinations of parameters with regard to impaired glucose tolerance. A total of 260 patients were included in the evaluation; 39% had impaired glucose tolerance and 12% had diabetes mellitus. A combination of HbA1c of > or =6%, a venous fasting glucose of > or =110 mg/dl, an age of > or =55 years, a systolic blood pressure of > or =140 mmHg and an enlarged waist size is highly predictive of impaired glucose tolerance.

[Malaria in the emergency room. Results of the emergency treatment of 137 patients with symptomatic malaria]. / Malaria in der Notaufnahme. Ergebnisse der Notfallbehandlung bei 137 Patienten mit symptomatischer Malaria.

OBJECTIVE: To assess characteristics and outcome of emergency patients with acute malaria. PATIENTS AND METHODS: We retrospectively assessed the clinical and laboratory parameters of 137 consecutive patients (87 males, 50 females; median age 37 years, range 17 - 67 years) presenting with acute malaria to our tertiary care center between 1992 and 2002. RESULTS: Falciparum malaria was diagnosed in 116/137 and tertian malaria in 19/137 patients; a single patient was infected with both parasites while in another case the type of parasite remained unclear. Infections were acquired in Africa (121), Asia , and in the Americas . One traveler visited multiple continents. Only 36 % (50/137) of patients had used malaria chemoprophylaxis. 128/137 patients were treated as in-patients; 22 of these had to be treated on an intensive care unit. According to the criteria of the German Society of Tropical Medicine, 44/137 (32 %; 95 % confidence interval (CI): 25 - 40 %) patients suffered from complicated malaria. The overall mortality rate was 2/137 (1.5 %; 95 % CI: 0,4 - 5.2 %); the mortality rate of complicated malaria tropica was 2/44 (4,5 %; 95 % CI 1,3 - 15 %). Patients with complicated malaria were significantly older than those with uncomplicated malaria. Median length of hospital stay was 4 days in uncomplicated and 9 days in complicated cases. Based on costs of EUR 2500 per case, an attack rate of > 3 % in East African travelers and a cost of EUR 55 for a chemoprophylaxis with mefloquine, chemoprophylaxis is cost-effective. CONCLUSION: In our retrospective analysis, complicated malaria tropica was associated with older age. Although malaria causes considerable morbidity, the overall mortality from severe malaria is low. Reinforcement of chemoprophylaxis especially in travelers to Africa could reduce malaria cases and is cost-effective.

Gas chromatographic/mass spectrometric assays for oxcarbazepine and its main metabolites, 10-hydroxy-carbazepine and carbazepine-10,11-trans-diol.

Oxcarbazepine (OCB) cannot be measured undecomposed by gas chromatography, not even when injected into a cooled, inert fused-silica capillary column. The bis-trimethylsilyl derivatives of the enol of OCB and of its main metabolite, 10-hydroxy-carbazepine (10-OH-CB), and the tris-trimethylsilyl derivative of carbazepine-10,11-trans-diol (CB-trans-diol) can be obtained easily at room temperature and are well suited for gas chromatographic and gas chromatographic/mass spectrometric analysis. Thermal decomposition to the substituted iminostilbene derivatives occurs only to the extent of a few per cent under the conditions described. Two gas chromatographic/mass spectrometric assays have been developed: one for the simultaneous quantification of OCB and 10-OH-CB, the other for CB-trans-diol. Both assays use carbazepine-10,11-cis-diol as the internal standard. Using 0.5 ml of plasma, limits of detection of 0.1, 0.1 and 1 ng/ml were obtained for OCB, 10-OH-CB and CB-trans-diol, respectively. CB-trans-diol is also the main metabolite of carbamazepine in patients under maintenance therapy. The kinetics of 15N-labelled CB-trans-diol derived from a single dose of (15N)carbamazepine has been measured in plasma and urine of patients and volunteers receiving (15N)carbamazepine in several studies.

Gas chromatographic assay for oxcarbazepine and its main metabolites in plasma.

The new anti-epileptic drug oxcarbazepine is temperature-labile and decomposes under the conditions of gas chromatography, even when injected into a cooled, inert, fused-silica capillary column. In contrast, the trimethylsilyl derivative of oxcarbazepine is stable. The bis-trimethylsilyl derivatives of the enol of oxcarbazepine and of its active metabolite, 10-hydroxycarbazepine, and the tris-trimethylsilyl derivative of carbazepine-10,11-trans-diol can be synthesized easily at room temperature. Using the readily available carbamazepine as internal standard, a simple gas chromatographic assay was developed for the simultaneous routine measurement of these three compounds at therapeutic levels. This assay is ten times more sensitive to oxcarbazepine than the previously described high-performance liquid chromatographic assays. It involves a single-step solvent extraction, uses a fused-silica capillary column and a flame ionization detector. On processing 0.5 ml of plasma, limits of detection of 10 ng/ml were obtained for oxcarbazepine and 10-hydroxycarbazepine and a limit of detection of 25 ng/ml for carbazepine-10,11-trans-diol.

The metabolism of tramadol by human liver microsomes.

The metabolism of tramadol was investigated in vitro using microsomal fractions of human liver. The parent compound and its main metabolites were determined by a newly developed high performance liquid chromatography assay. O-demethylation of tramadol was found to be stereoselective. The Vmax of the O-demethylation of (-)-tramadol was 210 pmol.mg-1.min-1, whereas (+)-tramadol was O-demethylated with a Vmax of 125 pmol.mg-1.min-1. The Km for both enantiomers was determined to be 210 microM. O-demethylation was inhibited competitively by quinidine (ki = 15 nM) and propafenone (ki = 34 nM). N-demethylation was also stereoselective, preferentially metabolizing the (+)-enantiomer. Whereas O-demethylation displayed monophasic Michaelis-Menten kinetics, N-demethylation was best described by a two-site model. Competitive inhibition of the O-demethylation both by quinidine and propafenone suggests that O-demethylation is carried out by P-450IID6.

Pharmacokinetics of oxcarbazepine and 10-hydroxy-carbazepine in the newborn child of an oxcarbazepine-treated mother.

Gaschromatography--mass spectrometry (GC/MS) was used to determine plasma levels of oxcarbazepine (OCB) and its main metabolite in a newborn girl and her OCB-treated mother during the first five post partum days. At delivery the maternal and neonatal plasma concentrations were in the same range, indicating considerable placental transfer of both substances. In spite of ingestion of both substances via breast milk, there was no accumulation in the baby. On the fifth post partum day OCB and 10-hydroxy-carbazepine (10-OH-CB) levels in plasma in the newborn were only 12 and 7%, respectively, of the values found on the first day after delivery.

High-performance liquid chromatographic assay for the simultaneous determination of tramadol and its metabolites in microsomal fractions of human liver.

A high-performance liquid chromatographic assay for the quantitative determination of the opioid analgesic tramadol and its metabolites is described. A homologue of tramadol [1-(m-hydroxyphenyl)-2-(N-ethyl-N-methylaminomethyl)cycloheptane-1 -ol hydrochloride] is used as internal standard. The assay allows the determination of tramadol O- and N-demethylation activity in vitro in microsomal fractions of human liver. Tramadol and its in vitro generated Phase I metabolites are extracted by a one-step extraction procedure from microsomal incubation mixtures using methylene chloride. Extraction efficiencies of tramadol, O-demethyltramadol and mono-N-demethyltramadol were 70, 91 and 94% respectively. The isocratic high-performance liquid chromatographic system employs a C18 reversed-phase column. The mobile phase is a mixture of methanol, ammonium hydrogencarbonate solution and ammonium hydroxide solution. Sensitivity of the assay was 0.5, 0.2 and 0.2 microgram/ml for tramadol, O-demethyltramadol and mono-N-demethyltramadol, respectively. Within-run precision of the overall assay was 13, 3.1 and 7.6% for tramadol, O-demethyltramadol and mono-N-demethyltramadol, respectively. Accuracy of the assay was determined as mean differences of concentrations added and found in microsomal fractions. It was -2.4% for tramadol, -0.85% for O-demethyltramadol and 0.32% for mono-N-demethyltramadol.

[Pharmacokinetics of colloidal bismuth subcitrate. Solution versus tablet]. / Pharmakokinetik von kolloidalem Wismutsubcitrat Lösung versus Tablette.

The aim of the present study was the investigation of the pharmacokinetics of bismuth after application of different preparations of colloid bismuth subcitrate (CBS; CAS 57644-54-9). 6 healthy volunteers were recommended to take a solution containing 240 mg CBS b.d. before breakfast and before the evening meal for 2 weeks, whereas 6 other volunteers received tablets containing 120 mg CBS 2 b.d. In both groups resulting daily CBS dose was 480 mg. On day 7 and day 14, 24 h urine excretion of bismuth was found to be significantly lower after application of the solution as compared to the one after application of the tablet (day 7: solution 110 micrograms/day--table 872 micrograms/day; day 14: solution 133 micrograms/day--table 872 micrograms/day; p < 0.05). After a single dose of 240 mg of CBS plasma AUC amounted to 42.8 micrograms/ml.h and 4.2 micrograms/ml.h after application of the tablet and the solution, respectively. Our results demonstrate that systemic bismuth load is markedly lower after application of the CBS solution as compared to the CBS tablet.

A gas chromatographic/mass spectrometric assay for prenylamine suitable for pharmacokinetic studies of the racemate and the enantiomers.

A sensitive assay for prenylamine and dideuteroprenylamine (racemic or pseudo-racemate) has been developed and used in human pharmacokinetic studies. Plasma levels of prenylamine could be measured up to 50 h after a single oral therapeutic dose. The extracted drug was derivatized with pentafluoropropionic anhydride in acetonitrile. The dried samples were reconstituted in decane; an aliquot was injected into a fused-silica capillary in a cooled on-column injector. The base peaks in the electron impact mass spectra of the compounds--derived by loss of a benzyl radical--at m/z 384, 386 and 390 were measured for prenylamine, (D2)-prenylamine and the internal standard hexahydroprenylamine, respectively. The sensitivity of this assay--limit of detection 0.2 ng ml-1 plasma with a signal-to-noise ratio of 5:1--allowed measurement of the kinetics of the racemate and of both stereoisomers for the first time. In man, the (+)-isomer was eliminated considerably faster than the (-)-prenylamine; the area under the plasma concentration time curve (AUC) of the (+)-isomer was only about 1/4 of the AUC of (-)-prenylamine.

Sparteine oxidation polymorphism: phenotyping by measurement of sparteine and its dehydrometabolites in plasma.

Phenotyping of the ability to oxidize sparteine was markedly facilitated by analyzing sparteine and dehydrosparteines in a single plasma sample by gas chromatography. The definitive identification of extensive and poor metabolizers was possible only 90 min after ingestion of 100 mg sparteine sulphate. In 121 healthy volunteers determination of the plasma level ratio was compared to the established determination of the metabolic ratio in urine. In each subject the alloted phenotype was the same by both methods. Plasma and urine analysis showed 9.9% of poor metabolizers.