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In a cross-over study on twelve healthy volunteers cefpodoxime proxetil (CAS 87239-81-4) and acetylcysteine (CAS 616-91-1) were evaluated for possible pharmacokinetic interactions. After a standardized breakfast, the subjects received p.o. either 200 mg cefpodoxime administered as cefpodoxime proxetil (reference) or 200 mg cefpodoxime and 200 mg acetylcysteine (test). To determine the pharmacokinetic profile of cefpodoxime the plasma concentrations were determined by HPLC. The plasma concentration-time curve of cefpodoxime was very similar after both regimens, and with respect to cefpodoxime bioequivalence has been proven. The narrow range of 90% confidence intervals for the quotient test/reference for Cmax and AUC indicate reliable bioavailability of cefpodoxime proxetil independent of co-administered acetylcysteine.

A high-performance liquid chromatographic (HPLC) method is described for the simultaneous determination of acetylsalicylic acid (ASA) and its main metabolite salicylic acid (SA) in human plasma. Acidified plasma is deproteinized with acetonitrile which is separated from the aqueous layer by adding sodium chloride. ASA and SA are extracted into the acetonitrile layer with high yield, and determined by reversed-phase HPLC (column: Novapak C18 4 microns silica, 150 x 4 mm I.D.; eluent: 740 ml water, 900 microliters 85% orthophosphoric acid, 180 ml acetonitrile) and photometric detection (237 nm). 2-Methylbenzoic acid is used as internal standard. The method allows the determination of ASA and SA in human plasma as low as 100 ng/ml with good precision (better than 10%). The assay was used to determine the pharmacokinetic parameters of ASA and SA following oral administration of 100-500 mg ASA in healthy volunteers.

Clarithromycin is a new macrolide that has a longer half-life than erythromycin and is claimed to reach higher tissue concentrations. We aimed to investigate whether, following oral administration, the drug and its 14-hydroxy metabolite reach levels in lung tissue that are likely to be clinically effective against common respiratory pathogens. Ten patients undergoing diagnostic bronchoscopy received seven doses of clarithromycin, 500 mg b.i.d. orally. Bronchoscopy was performed at a mean time of 4.25 h after the last dose. At bronchoscopy, bronchial biopsies and bronchoalveolar lavage were performed. Clarithromycin and its 14-OH metabolite were measured in serum, bronchial biopsies, epithelial lining fluid (ELF) and alveolar cells. Mean levels of clarithromycin were 4.0 mg.l-1 in serum, 16.8 mg.kg in bronchial biopsies, 20.5 mg.l-1 in ELF and 372.7 mg.l-1 in alveolar cells. The equivalent levels of 14-OH metabolite were 0.7, 2.7, 1.9 and 38.6 mg.l-1, respectively. We conclude that there is considerable concentration of clarithromycin and its 14-OH metabolite in alveolar cells, and to a lesser extent in bronchial tissue and ELF; this implies efficacy against susceptible organisms at these sites.

Clarithromycin and its metabolite, 14-hydroxy-clarithromycin are active against a wide range of respiratory pathogens. Antibiotics generally penetrate poorly into respiratory secretions which may therefore continue to harbour bacteria following bronchial infection. We have studied sputum and serum concentrations of clarithromycin and 14-hydroxy-clarithromycin in eight patients with idiopathic bronchiectasis without infective exacerbations (five male, three female; mean age 53.3 years). Oral single dose administration of 250 or 500 mg clarithromycin, separated by at least 6 days, was given to each patient. Serum and sputum samples were collected (the latter by physiotherapy at 0, 1, 2, 4, 8, 24 and 0, 4, 8 and 24 h respectively after administration of each dose. Serum sol phase was obtained by high speed centrifugation and concentrations of clarithromycin and 14-hydroxy-clarithromycin were determined by high performance liquid chromatography. Serum Cmax for clarithromycin and 14-hydroxy-clarithromycin were 1.20 mg/L (3 h) and 0.37 mg/L (3.1 h) for clarithromycin (250 mg)) and were 2.78 mg/L (2.5 h) and 0.68 mg/L (2.6 h) for clarithromycin (500 mg) respectively. Sputum Cmax for clarithromycin and 14-hydroxy-clarithromycin were 0.52 mg/L (5 h) and 0.30 mg/L (5.5 h) for clarithromycin (250 mg) and were 1.59 mg/L (5 h) and 0.47 mg/L (5.5 h) for clarithromycin (500 mg) respectively. The sputum/serum percentage ratios at Cmax (sputum) for clarithromycin and 14-hydroxy-clarithromycin were 74.3% and 113.9% (250 mg) and 94.7% and 99.9% (500 mg) respectively. We conclude that oral administration of clarithromycin to patients with bronchiectasis results in rapid penetration into respiratory mucus with persistent drug concentrations that exceed its MIC for many respiratory pathogens.

The aims of this study were, to determine the pharmacokinetic parameters of clarithromycin and to study the passage of the drug into breast milk. Twelve patients (age 24 to 38; weight 44 to 83 kg), suffering from puerperal infections, were treated orally with 250 mg clarithromycin b.i.d. for 6 days. Samples of blood and breast milk were taken at timed intervals. The specimens were assayed for clarithromycin and its active metabolite 14-hydroxy-clarithromycin by HPLC and electrochemical detection. Serum concentrations of clarithromycin in the investigated patients were higher than those reported in healthy volunteers. The mean peak concentrations of clarithromycin and 14-hydroxy-clarithromycin in breast milk were about 25%, and 75% respectively of the corresponding serum concentrations. All patients recovered within 2 to 4 days and no drug-associated side effects (eg. gastrointestinal) were noted. Clarithromycin appears to be an appropriate antibiotic for the treatment of puerperal infections and (because of its considerable concentrations in breast milk) for puerperal mastitis as well.

In two groups of volunteers pharmacological parameters of the antihypotensive drug midodrine have been investigated. The first group of 12 male healthy volunteers received 2.5 mg midodrine hydrochloride intravenously, as drinking solution or as tablet according to a randomized cross-over design. Plasma and urine samples were analyzed for midodrine and its main metabolite ST 1059 by high-performance liquid chromatography. The mean maximum concentration in plasma for midodrine was 10 ng/ml 20-30 min after oral administration, for ST 1059 5 ng/ml after 1 h. Midodrine was eliminated with a terminal half-life of 0.5 h, ST 1059 with a half-life of 3 hrs. The mean area under the plasma-level vs. time curve (AUC) of ST 1059 after administration of 2.5 mg midodrine i.v. was 28.7 ng x h/ml, and similar for the other formulations which are considered to be bioequivalent. In a second group of 15 volunteers with postural hypotension midodrine (M) as alpha-sympathomimetic drug and oxilofrine (O) as beta-sympathomimetic drug was given i.v. in a randomized double blind study against placebo (P). Blood pressure (BP), heart rate (HR) and circulating catecholamines (CA) were determined before and after injections of the drugs as well as before and during 10 min of tilting. Echocardiographic parameters were obtained at rest before and after the administration of the drugs. Blood pressure remained unchanged at rest and during orthostasis after all agents injected. After oral administration of midodrine heart rate was decreased and systolic blood pressure increased significantly and dose-dependently. M lowered circulating noradrenaline.(ABSTRACT TRUNCATED AT 250 WORDS)

To evaluate the therapeutic value of various antihypotensive agents we investigated amezinium (AMZ; CAS 30578-37-1), dihydroergotamine (DHE; CAS 511-12-6), midodrine (MDD; CAS 42794-76-3), and oxilofrine (OXF; CAS 365-26-4) in volunteers during passive orthostasis in a randomized double-blind study against placebo (PCB). Blood pressure, heart rate, and circulating catecholamines were determined before and after i.v. injections of the mentioned agents before and during 10 min of passive orthostasis. Echocardiographic and venous plethysmographic data were obtained during resting before and after the administration of the drugs. Resting heart rate decreased after injection of PCB, AMZ, DHE, and MDD. During tilting no significant changes in heart rate could be observed. Blood pressure remained unchanged at rest and during orthostasis after all agents injected. DHE and MDD lowered circulating noradrenaline. Echocardiographic parameters were changed after administration of AMZ (increase in stroke volume index (SVI) and ejection fraction (EF)), MDD (increase in enddiastolic volume index and SVI), and OXF (increase in SVI, EF, and cardiac index). The venous capacity of the lower left leg was only significantly decreased after injection of DHE, indicating an increased venous tone of the leg veins. The observed changes in sympathetic and cardiovascular parameters are in agreement with their sympathomimetic actions and allow a differential therapeutic classification: DHE and MDD are suitable agents for patients with sympathotonic orthostatic reaction; if asympathotonic orthostatic reaction occurs MDD, AMX and OXF should be recommended to those patients.

The chemical structure of an unknown metabolite of ciprofloxacin (CAS 85721-33-1) is characterized by means of reversed phase ion pair liquid chromatography, absorption and fluorescence spectroscopy, partition coefficients as well as chemical and enzymatic hydrolytic degradation. A chemical structure of the unknown metabolite is proposed: N-formyl-desethylen-ciprofloxacin. It can be formed as an intermediate in the oxidative degradation of ciprofloxacin via oxociprofloxacin to desethylen-ciprofloxacin, or it may be formed by conjugation of desethylen-ciprofloxacin with formic acid. The amounts found in plasma and urine of patients were in the range of desethylen-ciprofloxacin, i.e. about 1% of the parent compound.

In a three-way cross-over study the bioavailability of cefuroxime was determined in 12 healthy volunteers after oral administration of 250 mg as cefuroxime axetil (Elobact; CAS 64544-07-6) in a plain aqueous suspension and as tablets from different batches. The tablet formulations showed nearly identical pharmacokinetic parameters and were bioequivalent. The mean maximum serum concentration was 4.7 micrograms/ml, achieved after 2.1 h. The serum half-live was 1.2-1.4 h, the area under the serum concentration-time curve was 14.3-14.4 micrograms/ml.h and the urinary recovery of unchanged cefuroxime was 54%. The bioavailability of cefuroxime after administration of cefuroxime axetil in aqueous suspension was lower, but bio-inequivalence was not demonstrated.

Thirty youngs and children were submitted to surgical reconstruction of excavated chest. To prevent risk of infections (by Staphylococcus and mixed gram-negative flora) preoperative 100 mg/Kg body weight of cefotaxime was given. In all patients the operative wounds healed regularly. To evaluate cefotaxime level and that of its metabolites raised in the tissues, the very sensibles method HPLC was applied. Thus 45 minutes after antibiotic somministration, very high levels were present in cartilage 9.8 mmg/gr and in bones (9.3 mmg/gr). Related to Staphylococcus aureus (MHK 90 of about 2 mmg/ml) results are of value also for other surgical orthopedic operations.

The bioavailability of doxycycline (Doxy-Diolan 100 tablets, test, active substances: 100 mg doxycyclin per tablet) was compared with that of another commercially available tablet-formulation containing the same active substance (reference). In a cross-over study, 16 young healthy male volunteers were administered in fasting state orally by one tablet containing 100 mg active substance. The concentrations of doxycycline were determined in plasma and saliva by a high-performance liquid chromatographic assay. Mean maximum plasma concentration (cmax +/- standard deviation) of doxycycline were 1.57 +/- 0.40 micrograms/ml (test) and 1.59 +/- 0.38 micrograms/ml (reference), respectively, and were reached 1.47 +/- 0.55 h and 1.66 +/- 0.57 h after administration. Plasma half-lives were 16.6 +/- 2.9 h and 16.8 +/- 3.0 h, the areas under the plasma concentration-time curves (AUC0-00) 29.3 +/- 4.5 mg/l.h and 29.7 +/- 4.4 mg/l.h. The concentration of doxycycline in saliva were low, median maximum concentrations of 50 ng/ml were measured 1-2 h after administration. The statistical evaluation revealed bioequivalence between both drugs.

Three galenic formulations of cefixime (tablet, syrup and dry suspension) containing 200 mg each were compared with respect to their relative bioavailability in twelve healthy volunteers. All three formulations showed reliable absorption. Mean peak plasma concentrations were reached after 3.3-3.5 h, mean terminal half lives were 2.9-3.1 h. 18-24% of the dose administered were recovered unchanged in the urine. Best bioavailability was obtained with the dry suspension (AUC0-infinity = 25.8 +/- 7.0 micrograms/ml h; Cmax = 3.4 +/- 0.9 microgram/ml), followed by the tablet (AUC0-infinity = 20.9 +/- 8.1 micrograms/ml h; Cmax = 3.0 +/- 1.0 micrograms/ml) and the syrup which is based on triglycerides (AUC0-infinity = 17.8 +/- 5.9 micrograms/ml h; Cmax = 2.4 +/- 0.7 micrograms/ml). The statistical analysis resulted in bioinequivalence between dry suspension and syrup. It is concluded that best bioavailability of cefixime after oral administration is guaranteed when taken in an "aqueous medium" either as dry suspension or as tablet with "plenty of liquid".

The pharmacokinetic parameters of cefixime were determined in healthy volunteers following oral administration of 200 mg cefixime as tablet, syrup and dry suspension, respectively. All three galenic formulations showed reliable absorption. Mean peak plasma concentrations amounted to 2.4-3.4 mg/l and were reached after 3.3-3.5 h. Mean terminal half-lives were 2.9-3.1 h. The mean areas under the plasma concentration-time curves ranged between 18 and 26 mg/l.h; 18-24% of the dose administered were recovered unchanged in the urine. The best bioavailability was obtained with the dry suspension followed by the tablet and the syrup. With respect to the ester pro-drug cephalosporins, cefuroxime axetil, cefetamet pivoxyl and cefotiam hexetil, cefixime exhibits higher plasma half-life and area under the curve as well as, comparable absolute bioavailability but consistently lower urinary recovery which indicates higher non-renal clearance.

Cefotiam hexetil is a pro-drug of cefotiam available for oral administration. To evaluate cefotiam concentrations at the active site in skin and soft-tissue infections, drug levels in skin suction blister fluid (SBF), cantharides blister fluid (CBF) and serum were determined. Six healthy subjects received oral cefotiam 400 mg as cefotiam hexetil. On an other day 200 mg was injected intravenously. Following the oral dose, the bioavailability of cefotiam was 45.5%, and the maximum concentration in serum of 2.6 mg.l-1 was obtained at 2.1 h. Peak concentrations in both types of blister fluid (0.9 mg.l-1) were significantly lower than after the iv dose (SBF 1.4 mg.l-1, CBF 1.5 mg.l-1), and the peak levels occurred later (3.3 versus 1.5 h in CBF). Despite the delay, the extent of penetration was about 100% following either mode of administration (SBF, iv dose 112%, oral dose 117%). The cefotiam level in skin blister fluids declined significantly more slowly than the serum level. Following the oral dose, the mean terminal half life was serum 0.8 h, SBF 2.6 h and CBF 4.6 h. Cefotiam concentrations in the blister fluids were close to the MIC90 of Staphylococcus aureus, S. epidermis and H. influenzae and exceeded the MIC90 of Streptococci, E. coli and Proteus mirabilis. Thus, the oral administration of cefotiam 400 mg t.i.d. should be curative in the majority of bacterial infections of the skin and soft-tissues.

Studies in vitro showed that at concentrations of 1 and 4 mg/L ofloxacin inhibited 94 and 99% of the Gram-negative pathogens in isolates cultured from the urine of patients with complicated urinary tract infections (UTI). Against Gram-positive bacteria, 60 and 100% were inhibited at the corresponding concentrations. Comparisons of the MIC90 values of 8 quinolones showed the decreasing order of in vitro antibacterial activity to be ciprofloxacin, ofloxacin, norfloxacin, pefloxacin, enoxacin, pipemidic acid, nalidixic acid and cinoxacin. After an oral dose of ofloxacin 400mg, the mean peak serum concentration in 10 elderly patients was 5.5 mg/L and mean renal excretion during 24 hours was 41%. In 17 patients undergoing transurethral resection of the prostate, ofloxacin 400mg was given for perioperative prophylaxis. Two to 4.5 hours after administration, the median concentrations in prostatic secretion (5 patients) and prostatic adenoma tissue were 4.0 mg/L and 4.1 mg/kg, respectively. The corresponding serum concentrations of ofloxacin were 3.4 and 3.9 mg/L, respectively. In a group of 10 patients, 14.5 to 19.5 hours after oral administration of ofloxacin 400mg the median serum and prostatic adenoma tissue concentrations of ofloxacin were 1.9 mg/L and 1.2 mg/kg, respectively. The in vitro activity of ofloxacin concentrations attained in serum, urine, prostatic secretion and adenoma tissue show that it appears to be well suited for the treatment of complicated UTI.

A simple routine method is described for simultaneous assay of total urinary adrenaline, noradrenaline and dopamine. The catecholamines are pre-purified on a small ion-exchange column, separated by reversed phase ion-pair liquid chromatography, and are quantitated by electrochemical detection. The method was routinely applied to 422 urines. Elevated values were found in four urine specimens obtained from patients with histologically proven phaeochromocytomas. Virtually no interference by endogenous or exogenous compounds was found. Values for urinary catecholamines determined by fluorimetric analysis agreed with those obtained by high pressure liquid chromatography with electrochemical detection. Within-day CVs for the compounds ranged from 5.2-11.9%, between-day CVs from 3.3-6.6%. The normal range (95% confidence level) was 20-230 micrograms/24 h for noradrenaline and 1-35 micrograms/24 h for adrenaline.

For perioperative prophylaxis 200 mg ciprofloxacin were administered as a short intravenous infusion to 17 patients aged 57-84 years before transurethral resection (TUR-P) or transvesicular enucleation (TVP) of the prostate. 13 patients were injected simultaneously with 2.5 g ioxitalamic acid i.v. to determine the kidney function. In 11 patients the plasma concentrations were assayed and the pharmacokinetic parameters calculated. At the end of infusion the concentrations of ciprofloxacin in plasma reached 4.2 +/- 0.8 microgram/ml and decreased after a fast distribution period (plasma half-life 0.20 +/- 0.09 h) with a terminal half-life of 4.2 +/- 1.3 h to 0.2 +/- 0.09 microgram/ml after 10 h. The apparent volume of distribution in steady state was 183 +/- 45% of body weight, the plasma clearance 457 +/- 146 ml/min/70 kg. The average concentrations in prostatic adenoma tissue were at all sampling times higher (2fold) than in plasma. The mean concentrations in prostatic secretion were about half of the respective plasma concentrations. High concentrations of the concomitantly administered ioxitalamic acid in prostatic secretion are considered as an indicator of urinary contamination. In those patients high ciprofloxacin concentrations in prostatic secretion are not reliable.

To study the role of peripheral catecholamines in plasma and different tissues in neurogenic hypertension we measured directly blood pressure, maximum rate of left ventricular pressure rise (dp/dtmax) and heart rate through an aortic catheter 5 weeks after total sino-aortic baroreceptor deafferentation in male Sprague-Dawley rats. Blood samples were collected through the same catheter to determine plasma catecholamine concentrations. Blood pressure and dp/dtmax were significantly higher in neurogenic-hypertensive rats when compared with sham operated rats. Plasma noradrenaline concentrations and plasma adrenaline concentrations reached significantly higher levels in neurogenic-hypertensive rats. In the heart noradrenaline content was lower (when calculated per g wet weight) and in the adrenal medulla adrenaline content was higher in neurogenic-hypertensive rats, when compared with sham operated controls. A significant positive correlation was found between dp/dtmax and plasma noradrenaline concentrations. It is concluded that sino-aortic baroreceptor deafferentation produces a significant chronic hypertension, probably supported by elevated plasma catecholamine concentrations and enhanced synthesis and release of adrenaline from adrenal medulla.

In plasma and urine of 10 healthy volunteers after intravenous administration of 4 g mezlocillin and piperacillin, respectively, the parent compounds as well as degradation products were assayed by high-performance liquid chromatography. Ioxitalamic acid, a renal contrast medium, was administered simultaneously, in order to measure the glomerular filtration rate, and to control the collection of 24-h urine. As metabolite of mezlocillin the corresponding penicilloic acid only was found, whereas in the case of piperacillin a further degradation product was observed. Half of the doses given was recovered in the urine as unchanged drugs, and in addition 5-10% as metabolites. No differences were found in the pharmacokinetic behaviour of both antibiotics.

Biochemical and pharmacological investigations about the effect of the antidepressant drug viloxazine (Vivalan) on catecholamine metabolism in rats led to the following results: Viloxazine exerts a dose and time dependent inhibition of monoamine oxidase activity of brain and liver mitochondrial fraction and tissue homogenates of hypothalamus, heart, liver, and adrenal glands, both in vitro and after oral and parenteral administration in vivo. Consequently, an increase in catecholamine concentrations in brain of rats could be observed after pretreatment with viloxazine. In addition brain serotonin concentrations rose and 5-hydroxy-indoleacetic acid was diminished. However, characterization of inhibition of monoamine oxidase activity by viloxazine in vitro revealed: Compared to the specific inhibitors clorgyline for MAO-A- and pargyline for MAO-B-activity, viloxazine was a very weak inhibitor both for MAO-A and MAO-B in vitro. The type of inhibition was competitive and reversible. From the presented results and the results obtained by other laboratories it is concluded that inhibition of monoamine oxidase activity by viloxazine, although clearly demonstrated in animal experiments, may not be the only mechanism for an antidepressant action of the drug in man.

In rat serum as well as in human serum and bile after injection of cefotaxime (CTX), the parent compound and the active metabolite desacetyl cefotaxime (dCTX) have been demonstrated by quantitative analysis with high-performance liquid chromatography (HPLC). Simultaneous determination of CTX by bioassay using test organisms sensitive to both CTX and dCTX resulted in spuriously high concentration readings of CTX. Using dCTX insensitive test organisms concentrations of cefotaxime obtained by agar diffusion test and by assay with HPLC were highly correlated. In human serum and bile after i.v. injection of 2 g CTX, as may be administered therapeutically, high concentrations of dCTX were observed. dCTX has a longer elimination half-life than the parent molecule. It is concluded that the measurement of CTX in biological fluids should be performed by HPLC or by bioassay with a selective test organism in order to obtain correct pharmacokinetic parameters.

In eleven volunteers and 39 patients undergoing transurethral resection of the prostate or bladder tumor, concentrations of enoxacin were measured in seminal fluid (volunteers), in prostatic fluid (volunteers, patients) and in prostatic adenoma tissue (patients) after oral (400 mg) administration and intravenous (428 mg) infusion (60 min) of enoxacin. Simultaneously 2.534 g of iothalamic acid was i.v. injected to identify possible urinary contamination. The concentrations of enoxacin in seminal fluid after 2-4 h and in prostatic tissue after about 1-4 h and 14-16 h exceeded plasma concentrations more than two-fold. The concentrations in prostatic fluid after 1-4 h were about half the plasma concentrations. Venous blood samples were taken after intravenous infusion at intervals of up to 24 h in a total of 14 patients. The mean plasma concentration of enoxacin decreased from its maximum of 6.9 mg/l at the end of infusion to 0.5 mg/l at 12 h after administration. A terminal half life of 6.65 h was calculated according to an open two-compartment model.

In ten healthy volunteers the plasma and urine concentrations of heptaminol (Heptylon) were determined by high-performance liquid chromatography after intravenous administration of 250 mg heptaminol and oral intake of 2 x 150 mg heptaminol in tablet form, and the pharmacokinetic parameters were calculated. Heptaminol was rapidly and entirely absorbed following oral administration of heptaminol. Mean plasma peak concentrations of 1.6 mg/l were reached after 1.8 h, the area under the plasma concentration-time curve was equal to that after intravenous administration. The dominant terminal plasma half-life was 2.5-2.7 h. The total clearance amounted to 700 ml/min, and nearly all the dose given was recovered unchanged in urine within 24 h, indicating renal elimination by glomerular filtration and tubular secretion without metabolization.

Compared to sham-operated controls 5 weeks after surgery neurogenic hypertensive rats with sino-aortic baroreceptor deafferentation had higher blood pressure, higher plasma noradrenaline and adrenaline levels, lower heart noradrenaline concentrations, higher adrenomedullary adrenaline levels and increased cardiac intraventricular pressure (dp/dtmax).

In an open, prospective, non-randomised study involving 112 patients undergoing elective colorectal surgery, the effect of perioperative prophylaxis with cefotetan was investigated. Cefotetan (2g) was administered, pre- and intra-operatively only. Preoperative bowel preparation was done by the standardised "Würzburg Method" i.e. oral metronidazole pre and post orthograde lavage. Mucosal biopsies were obtained from the resected colon and simultaneously serum samples were taken to determine tissue and serum levels respectively. Antibiotic serum and gut mucosal levels were well in excess of the minimum inhibitory concentration (MIC90) levels of the isolated bacteria. Wound infections occurred in only 2 patients. Cefotetan was well tolerated and no adverse events were noted. In prolonged colorectal surgery, an antibiotic such as cefotetan with a long half-life is to be recommended.

The minimal inhibitory concentrations (MICs) of aztreonam and cefotaxime were determined against 400 isolates from urological in-patients with complicated and/or hospital acquired urinary tract infections (UTI). Against the Gram-negative rods the activities of both antibiotics were comparable except for higher activity of aztreonam against Pseudomonas aeruginosa. The pharmacokinetic study in nine elderly patients showed a prolonged plasma half life of aztreonam (2.7 h) as compared to younger volunteers (1.6-1.9 h). In a prospective randomized study 39 urological patients with complicated and/or hospital acquired UTI were treated with 1 g aztreonam or cefotaxime iv twice daily for 4 to 15 days. Cure was obtained in 5 out of 18 patients in the aztreonam and 7 out of 20 patients in the cefotaxime group. There were 3 superinfections, 7 relapses and 3 reinfections in the aztreonam group and 1 failure, 1 superinfection, 6 relapses and 5 reinfections in the cefotaxime group. There was no significant difference in therapeutic efficacy between the two antibiotics. Both antibiotics were tolerated well and seem to be equally effective in the treatment of complicated UTI caused by sensitive organisms.

To establish dose-response relationships for nicotine (acute and subacute administration), we measured hemodynamic parameters as well as circulating and tissue catecholamines in sympathetically innervated organs in rats. We also investigated nicotines's influence on adrenoceptor binding sites of the heart and on serotonin metabolism. In conscious and anesthetized rats, we found a dose-dependent increase in circulating catecholamines after acute injection of nicotine. At low doses nicotine released norepinephrine, resulting in a decrease of blood flow and heart rate, whereas high doses of nicotine released epinephrine, resulting in a reversal of the cardiovascular parameters investigated. In the heart norepinephrine concentration increased after nicotine application. In the lung epinephrine rose markedly, whereas serotonin and 5-hydroxyindolacetic acid were diminished. After subacute administration of nicotine the number of binding sites for 3H-Dihydroalprenolol in the heart was significantly reduced, whereas norepinephrine content was increased. Dopamine, serotonin, and 5-hydroxyindolacetic acid were increased in the hypothalamus. Our findings show that nicotine not only affects peripheral and central catecholaminergic neurons, but also central serotoninergic neurons, thus enhancing turnover of these amines.

In 12 elderly patients, plasma, prostatic secretion and adenoma tissue concentrations of fleroxacin were determined 1-4 h following oral administration of 400 mg. The plasma concentrations ranged between 0.4 and 5.5 micrograms/ml (median 3.7 micrograms/ml), the mean tissue concentrations were slightly higher. The concentrations in prostatic secretion were about one third of the simultaneous plasma concentrations. High concentrations of the concomitantly administered ioxithalamic acid in prostatic secretion are considered as indicative of urinary contamination, and in this case the fleroxacin concentrations are questionable. The drug levels in prostatic adenoma tissue were similar to the concomitantly measured plasma levels.

In a randomised clinical trial, 102 women who underwent vaginal hysterectomy were given a single preoperative 2g dose of cefotetan (CTT) (52 pts) or three perioperative 2g doses of cefoxitin (CFX) plus 0.5g metronidazole (50 pts) as antibiotic prophylaxis. No statistically significant differences between the groups were detected in the clinical response (100% for both groups). The incidence of major wound infection (2% CTT and 0% CFX) were also comparable between the two treatment groups; post-operative changes in body temperature, duration of hospitalisation and post-operative urinary tract infections (16% CTT and 20% CFX) were similar. Both drugs were well tolerated. Twenty nine of the 102 patients were further investigated to determine the pharmacokinetics following a single 2g dose of CTT or CFX, in both serum and tissue. Although both antibiotics provided good concentrations during the early phase of surgery, CTT levels persisted for a longer time period. These results confirm that single dose cefotetan is equally as effective and safe as multiple dose cefoxitin plus metronidazole for prophylaxis in patients undergoing vaginal hysterectomy.

The pharmacokinetics of midodrin (alpha-2,5-dimethoxyphenyl-beta-glycinamidoethanol hydrochloride, ST 1085) and its main metabolite ST 1059 (alpha-2,5-dimethoxyphenyl-beta-aminoethanol hydrochloride) have been investigated in 12 male healthy volunteers. 2.5 mg midodrin hydrochloride were applied intravenously, as drinking solution or as tablet (Gutron) according to a randomized cross-over design. Plasma and urine samples collected up to 24 h after application were analyzed by high-performance liquid chromatography with fluorescence detection. The mean maximum concentration in plasma for midodrin was ca. 10 ng/ml 20-30 min after oral administration, for ST 1059 ca. 5 ng/ml after 1 h. Midodrin was eliminated with a terminal half-life of 0.5 h. The half-life of ST 1059 was determined to be 3 h. The mean area under the plasma-level vs. time curve (AUC) of ST 1059 after administration of 2.5 mg midodrin i.v. was 28.7 ng X h/ml, and as drinking solution or as tablet 25.7 and 25.6 ng X h/ml, respectively. The data of 10 volunteers could be used for the calculations of the bioavailability of ST 1059 by the AUC. Assuming an interval of equivalence of 0.75-1.25 because of the relatively small number of volunteers, the three galenical formulations are considered to be equivalent.