Effect of single or consecutive administration of T-2588 on hepatic-injured male rats

The present study was carried out to examine the effect of single or consecutive administration of T-2588 on liver of male rat injured by the administration of D-galactosamine X HCl. The T-2588 was orally given to hepatic-injured rats at doses of 125 mg/kg and 1,000 mg/kg singly or for consecutive 5 days. A 10 ml/kg dose of the vehicle was orally given to control rats. The results obtained were summarized below. Single administration of T-2588. Twenty-four hours after a single administration of T-2588, the liver taken from control rats apparently indicated galactosamine-induced hepatitis. No drug-related alterations were observed in hepatic functional test, liver weight and histological examinations at either dose of T-2588. Galactosamine-induced hepatitis was not affected by a single administration of T-2588. Consecutive administration of T-2588. Twenty-four hours after a 5-consecutive-day administration of T-2588, galactosamine-induced hepatitis in control rats was restored to the normal state. The cure of galactosamine-induced hepatitis was not affected by a 5-consecutive-day administration of T-2588. The hepatic aldehyde dehydrogenase activity in hepatic-injured rats was not affected by a 5-consecutive-day administration of T-2588.     

General pharmacology of T-2588, a new oral cephem antibiotic

A new oral cephem antibiotic, T-2588, the pivaloyloxymethyl ester of (+)-(6R, 7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3- [(5-methyl-2H-tetrazol-2-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2. 0]oct-2-ene-2-carboxylic acid (T-2525), is mainly absorbed from the intestinal tract and biotransformed to T-2525 thereafter. General pharmacological activities of T-2588 were studied and following results were obtained. On the central nervous system, T-2588 did not show any effects at oral doses of 500-2,000 mg/kg and T-2525 produced only a slight elevation of body temperature in rabbits without any other effects at an intravenous dose of 500 mg/kg. On the respiratory and cardiovascular systems, T-2525 caused a slight hypotension and increased both respiratory rate and femoral blood flow, but no changes were observed in heart rate and electrocardiogram in dogs at an intravenous dose of 500 mg/kg. The T-2525 exerted no significant influence on blood pressure response to isoproterenol, acetylcholine or histamine, but showed a slight tendency to decrease pressor response to adrenaline in dogs at intravenous doses of 100-500 mg/kg. For the renal function in rats, T-2588 had no effects on urine volume, electrolytes and PSP excretion at oral doses of 500-2,000 mg/kg. Intravenous administration of T-2525 caused an increase of sodium excretion at 500 mg/kg and dose-dependent increases of PSP excretion at 20-500 mg/kg. Hematological studies revealed that both T-2588 at oral doses of 500-2,000 mg/kg and T-2525 at intravenous doses of 100-500 mg/kg had no effects on bleeding time in mice, blood coagulation and platelet aggregation in rats. The T-2588 exerted no effect on the gastrointestinal system in rats or mice and had no antiinflammatory activity in rats at oral doses of 500-2,000 mg/kg. The T-2525 scarcely affected the motilities of isolated smooth muscle preparations in experimental animals including stomach, ileum, colon, uterus, vas deferens and trachea at a concentration as high as 10(-3) g/ml. The T-2525 increased bile secretion in rats at intravenous doses of 100-500 mg/kg. The T-2525 slightly decreased the twitch tension of musculus gastrocnemius induced by electrical stimulation in rats at an intravenous dose of 500 mg/kg. These results indicate that T-2588 is a pharmacologically inactive antibiotic.     

Studies on absorption, distribution and excretion of 14C labeled pivaloyloxymethyl (+)-(6R,7R)- 7-[(Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]- 3-[(5-methyl-2H-tetrazol-2-yl)methyl]-8-oxo-5-thia- 1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate (14C-T-2588) in rats and mice

Absorption, distribution and excretion of T-2588 were studied in rats and mice using (aminothiazole-2-14C) T-2588 and (pivaloyloxymethyl-14C) T-2588. Results are summarized below. The binding rate of 14C-T-2525, an activated form of 14C-T-2588 in vivo, to serum protein was 90 approximately 100% in rats and mice after an oral administration of (aminothiazole-2-14C) T-2588. Blood levels of radioactivity reached to the highest concentration at 1 hour after an oral administration of (aminothiazole-2-14C) T-2588 to rats, and then gradually diminished. After an oral administration of (aminothiazole-2-14C) T-2588 to rats and mice, the highest radioactivity distribution was found in kidney among all the organs except stomach, intestine and bladder. Radioactivity was widely distributed into other organs such as adrenal, lung, liver, heart and pancreas. But little radioactivity was found in the brain. In new born rats, tissue levels of radioactivity were lower and diminished slower than those of adult rats. After an oral administration of (aminothiazole-2-14C) T-2588 to rats and mice, urinary excretion of radioactivity was about 26% and 35% of the dosed radioactivity in rats and mice, respectively, and fecal excretion was about 76% and 63% of the dosed radioactivity in rats and mice, respectively. Urinary and fecal excretion patterns of radioactivity after multiple oral administration of (aminothiazole-2-14C) T-2588 for 7 days to mice were similar to those after a single administration. This result suggests that T-2588 did not accumulate in the body. After an oral administration of (pivaloyloxymethyl-14C) T-2588 to rats and mice, urinary excretion was both about 8% of the dosed radioactivity, and fecal excretion was both about 6%. Then excretion of 14CO2 into respiratory air was about 55% and 66% of the dosed radioactivity in rats and mice, respectively. Biliary excretion was about 6.5% of the dosed radioactivity after an oral administration of (aminothiazole-2-14C) T-2588 to rats. Small amount of radioactivity was secreted to the milk after intravenous administration of (aminothiazole-2-14C) T-2525 to nursing rats. After an administration of (aminothiazole-2-14C) T-2588 to pregnant mice, radioactivity hardly transferred into the fetus.     

A pharmacokinetic and dynamic study of single nightly doses of conventional and controlled release formulations of trazodone

We studied the pharmacokinetics and dynamics of single evening oral doses of conventional capsules (100 mg) and a controlled release formulation (150 mg) of trazodone in 12 fasting and non-fasting young healthy volunteers. When corrected for the different doses used, there was no significant difference among the areas under the plasma concentration-time curves (AUC) for the conventional capsules and the controlled release tablets under fasting and non-fasting conditions. Both conventional and controlled release formulations were followed by a reduction in critical flicker fusion threshold (CFFT) and this effect was not influenced by the administration of food before dosing. After both conventional and controlled release formulations, blood pressure was significantly lower when medication had been given in the fasting state than when it had been given after food. The frequency of adverse symptoms was greater after the controlled release (150 mg) than after the conventional (100 mg) formulation. We conclude that there is no obvious advantage to the controlled release formulation (150 mg) and that conventional trazodone (100 mg) should be taken after food when it is given at night.     

T-2 toxin induced changes in liver and serum enzymes of rats

The effects on liver and serum enzymes of feeding a single dose (2 mg/kg) and daily doses (0.75 mg/kg) of T-2 toxin were studied in young male rats. Sample times were 8, 16 and 24 hr for single dose administration and 7, 14 and 21 days for daily dose administration. T-2 toxin in single and daily doses significantly reduced activities of hepatic glutamate pyruvate transaminase (GPT) and alkaline and acid phosphatases at all the sampling periods. In both feeding trials, levels of serum GPT increased, while that of acid and alkaline phosphatases significantly decreased at all the sampling times. This study indicates that the liver is affected by feeding T-2 toxin to rats.     

Overall clinical evaluation of cefprozil against infections in pediatric fields. Pediatric Study Group for Cefprozil]

Cefprozil (CFPZ, BMY-28100) granule preparation was studied for pharmacokinetic, bacteriological and clinical aspects in the pediatric infections. The results obtained are summarized as follows: 1. Serum concentrations and urinary excretion. The pharmacokinetics of CFPZ in pediatrics was investigated by single oral administration of fine granules at doses of 4.0, 7.5 and 15.0 mg/kg. Peak blood levels of CFPZ were 3.06, 4.62 and 9.65 micrograms/ml, respectively, at 1.00-1.30 hours after each dose and AUCs were 7.44, 12.50 and 27.01 micrograms.hr/ml, respectively. These data showed that Cmax and AUC depended on dose levels. T 1/2 (beta) at these dose levels were 1.03, 0.94 and 1.01 hours, respectively. There were no differences related to dose. Urinary recovery rates in the first 6 hours after administration were 51.5-57.1%. The pharmacokinetics of CFPZ before or after meals were also investigated at a dose of 7.5 mg/kg. Peak blood levels were 4.88 micrograms/ml at 1.17 hours after administration in the fasting state, and 4.30 micrograms/ml at 1.54 hours after administration in the non-fasting state. Delay of Tmax and slight decrease of Cmax were observed in the non-fasting state, but T 1/2 and AUC were 0.91 hour and 12.96 micrograms.hr/ml, respectively, in the non-fasting state, and were similar to those in the fasting state, 0.93 hour and 12.82 micrograms.hr/ml, respectively. Urinary recovery rates in the first 6 hours after administration were 63.8% in the fasting state and 50.7% in the non-fasting state. 2. Clinical results. Clinical efficacies of CFPZ granules in various infectious diseases were studied in 804 cases. Twenty nine cases, mostly viral or mycoplasmal infections, were excluded from the statistical analysis. The clinical efficacy rate in 527 cases with causative bacteria isolated was 97.2%; and in 248 cases from whom no significant isolate had been obtained was 96.0%. The clinical efficacy rate in 475 cases with monobacterial infections (proven by culture of isolates) was 97.3%, and that in 52 case with polybacterial infections was 96.2%. Haemophilus influenzae was isolated mostly from acute respiratory infections. In 88 cases from whom H. influenzae was isolated, clinical efficacy rate was 95.5%. In cases from whom H. influenzae was found concomitant by with Staphylococcus aureus, Streptococcus pyogenes or Streptococcus pneumoniae, the clinical efficacy rates were also high. The bacteriological eradication rate in cases with 582 strains was 83.3%; the eradication rate for Gram-positive organisms was 95.8%; and for Gram-negative organisms, it was 64.2%.(ABSTRACT TRUNCATED AT 400 WORDS)     

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Fimasartan Following Single and Repeated Oral Administration in the Fasted and Fed States in Healthy Subjects

Background and Objectives

Fimasartan (BR-A-657) is a novel, non-peptide angiotensin II receptor antagonist with a selective type I receptor blockade effect. Two first-in-human studies investigated the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of fimasartan.

Methods

Fasted single oral tablet doses of fimasartan 20–480mg or placebo were administered to 40 healthy male subjects (aged 19–54 years) in a double-blind, randomized, sequential-group design. Subjects receiving fimasartan 240mg also received the same treatment in the fed state after an interval of 7 days. In another study, oral tablet doses of fimasartan 120 and 360mg or placebo were given once daily for 7 days to groups of eight fasted healthy male subjects (aged 20–55 years) in a double-blind, randomized, sequential-group design. Safety and tolerability were assessed. The PK and PD of fimasartan were also evaluated and compared for the different doses.

Results

Fimasartan was safe and well tolerated, but with an increased incidence of low BP and postural dizziness for the 360mg dose after repeated administration. Fimasartan produced increases in plasma renin activity, angiotensin I and II, which were not dose dependent. Maximal increases occurred between 6 and 8 hours post-dose, lasting up to 48 hours. Fimasartan was absorbed rapidly after all doses and had a multiphasic distribution. Two peaks in the plasma concentration-time profile were observed in most subjects. Steady state was achieved after three doses, and accumulation was minimal after repeated doses for 7 days (24–30%). The effective half-life ranged from 9.84 to 13.2 hours. The systemic exposure of fimasartan was dose proportional, and no marked food effect was noted after administration of 240mg in the fed state. Urinary excretion of fimasartan was very low (1.74–2.51%), suggesting non-renal elimination.

Conclusion

Fimasartan had a good safety profile and was well tolerated after fasted single oral doses of 20–480mg, a fed single oral dose of 240mg, and fasted repeated oral doses of 120 and 360mg in healthy subjects. In addition, the PK and PD of fimasartan in this population were well characterized. Further studies are needed to evaluate the safety, efficacy, and dose-response relationship of fimasartan in patients with hypertension.     

Correlation of Dissolution Rate and Drug Absorption in Man

Abstract: Diazoxide blood levels in man were measured after single 600 mg oral doses in solution, capsule and tablet form. A high correlation was found between dissolution rate in 0.1 N-HCl and area under the 0–6 hour blood level curve. Griseofulvin absorption from 10 different preparations was studied in man. Plasma levels were followed for 1 day after a single oral 500 mg dose, and for 7 days after daily 500 mg doses. A high correlation was found between dissolution rate in simulated intestinal fluid and area under the 0–25, 49–173, and 0–173 hour plasma level curves.     

A study on the disulfiram-like reaction of T-2588. Influence of the consecutive administration of T-2588 on hepatic alcohol dehydrogenase and aldehyde dehydrogenase activities and blood levels of ethanol and acetaldehyde

A study on disulfiram-like reaction of T-2588 was carried out using Sprague-Dawley male rats. A 500 mg/kg/day dose of T-2588 was given orally to 14 male rats once daily for 7 days. Disulfiram (200 mg/kg/day X 3 days, p.o.), cephalexin (CEX) (500 mg/kg/day X 7 days, p.o.) and cefmetazole (CMZ) (500 mg/kg/day X 7 days, i.v.) were used as the positive control and 2 comparative controls, respectively. The results obtained were summarized below. Each parameter (aldehyde dehydrogenase activity and the blood aldehyde level) in the disulfiram-like reaction was not affected by the T-2588 administration. A marked inhibition of aldehyde dehydrogenase activity (low-Km ALDH, Enzyme I) and a significant increase of the blood aldehyde level were observed in the rats receiving disulfiram. No drug-related disulfiram-like reaction was induced in the male rats receiving CEX, while alterations similar to the disulfiram action were recognized in rats receiving CMZ.     

Comparative Pharmacokinetic and Pharmacodynamic Properties of Oral and Intravenous (+)-Sotalol in Healthy Volunteers

Abstract— The pharmacokinetic and pharmacodynamic properties of (+)-sotalol (BMY-5763) were studied to analyse the relationship between plasma concentration and QT_c prolongation in healthy male volunteers given single oral doses of 50, 100, 200 and 300 mg, repeated oral doses of 200 mg twice daily for 6·5 days, and single intravenous doses of 1·0 and 1·5 mg kg^?1. The plasma concentration of (+)-sotalol peaked about 3 h after oral administration and declined with a half-life of 7·9–9·7 h. The C_max and AUC showed dose-related increases, while the urinary recovery as the unchanged form remained constant (66–68% of the dose). During repeated oral administration the plasma concentration of (+)-sotalol reached almost a steady state on the 3rd day and there was no change in renal clearance of (+)-sotalol measured on the 1st, 4th and 7th days. After intravenous administration, (+)-sotalol in plasma decreased biexponentially with a terminal half-life of 7·6–8·3 h and the urinary recovery as unchanged drug amounted to 84–88% of the dose. The increase in QT interval was significant after a single oral administration except for the lowest dose, and regression analysis revealed a significant correlation between QT_c interval and concentration of (+)-sotalol in plasma. The same correlation was evident with repeated oral doses on the 1st, 4th and 7th days. In the case of single intravenous administrations of (+)-sotalol, a combined pharmacokinetic-pharmacodynamic model was attempted by assuming an effect compartment. This analysis was shown to be effective to adjust the lag of effect behind a rapid change in plasma concentration which occurred in the early distributive phase because there was no evidence that the metabolite made any significant contribution to the effect of (+)-sotalol.     

Laboratory and clinical studies of cefdinir 5% and 10% fine granules in pediatric field]

We have carried out laboratory and clinical studies on cefdinir (CFDN) 5% and 10% fine granule preparations. The results are summarized as follows. CFDN 5% fine granule preparation was given via oral route to each of 2 children in the fasting state at a single dose of 3 mg/kg. After administration, the mean peak plasma level of CFDN was 0.76 micrograms/ml at 4 hours and the mean half-life was 1.77 hours. The mean urinary excretion rate of CFDN was 31.5% in the first 12 hours after oral administration. CFDN 10% fine granule preparation and CFDN 100 mg capsule were given via oral route 3 children and to another child in the fasting state at single doses of 3 mg/kg and 2.63 mg/kg, respectively. After administration of 10% granules the mean peak plasma level of CFDN was 0.73 micrograms/ml at 2 hours and the mean half-life was 1.62 hours. The peak serum level obtained after administration of CFDN 100 mg capsule was 0.91 micrograms/ml at 2 hours and the half-life was 1.08 hours. The mean urinary excretion rate obtained with CFDN 10% fine granules was 26.2% in the first 8 hours after oral administration and the urinary excretion rate obtained with CFDN 100 mg capsule was 19.7% in the first 12 hours after oral administration. Treatment with CFDN 5% fine granules was made for a total of 48 cases of pediatric bacterial infections including 21 cases of tonsillitis, 12 cases of scarlet fever, 3 cases of pharyngitis, 5 cases of impetigo, 1 case of subcutaneous abscess, 1 case of furuncle, 5 cases of UTI. Results obtained were excellent in 30 cases, good in 18 cases. Treatment with CFDN 10% fine granules was made for a total of 16 cases of pediatric bacterial infections including 6 cases of tonsillitis, 3 cases of pneumonia, 4 cases of scarlet fever, 2 cases of impetigo, 1 case of UTI. Results obtained were excellent in 8 cases, good in 7 cases, poor in 1 case. No significant side effects due to the drugs were observed except 2 cases (1 case with 5% preparation and another with 10%) with eosinophilia, 3 cases (all with 5%) with diarrhea and 1 case each of elevated GOT & GPT (with 5%) and elevated GOT, GPT & Al-P (with 10%).     

Bacteriological, pharmacokinetic and clinical studies on cefteram pivoxil in the pediatric field

Bacteriological, pharmacokinetic and clinical studies were done on the effect of cefteram pivoxil (CFTM-PI, T-2588) (10% granules), a new oral cephalosporin, in the field of pediatrics. The results are summarized below. 1. Antibacterial activities Antibacterial activities of CFTM against Staphylococcus aureus and Streptococcus pyogenes were studied comparatively with activities of cefaclor (CCL), cephalexin (CEX) and ampicillin (ABPC). MICs of CFTM against S. aureus were distributed in a range between 0.78 and 12.5 micrograms/ml, with a peak value of 3.13 micrograms/ml, which were similar to MIC ranges of CEX and CCL. MICs of CFTM against all strains of S. pyogenes were less than or equal to 0.025 microgram/ml, which were similar to MIC of ABPC. CFTM was approximately 2 to 3 folds more effective than CCL or CEX. 2. Absorption and excretion. Serum concentrations and urinary excretions of CFTM were determined in doses of 3 mg/kg (non-fasting) and 6 mg/kg (non-fasting and fasting). In non-fasting subjects, peak concentrations of CFTM in serum were dose-dependent and were 1.15-2.3 micrograms/ml and 1.8-3.6 micrograms/ml at 2-3 hours, 0.125-0.78 micrograms/ml and 0.245-0.97 micrograms/ml at 6 hours, respectively, for the 2 dose levels. Serum half-lives were 1.03-2.65 hours for the dose of 3 mg/kg and 1.07-1.83 hours for 6 mg/kg. In fasting subjects, the mean peak serum concentrations were 1.73 micrograms/ml at 2 hours and 1.13 micrograms/ml at 6 hours for the dose of 6 mg/kg. Urinary recovery rates in the first 6 hours varied 5.3-19.2%. 3. Clinical study Clinical efficacies were examined in a total of 41 cases including 9 cases of bacterial pneumonia, 10 cases of bronchitis, 11 cases of tonsillitis, 7 cases of urinary tract infections, 3 cases of scarlet fever and 1 case of otitis media. Clinical efficacies were excellent in 30 cases, good in 10 cases, poor in 1 case, hence the efficacy rate was 97.6%. All of the 28 bacteria identified in these cases were eradicated after CFTM-PI treatments. No noticeable abnormalities were found as side effects. An elevation of eosinophil, an increase of platelet count and elevations of GOT and GPT were observed in 3 patients.     

Citrinin mycotoxicosis in the rabbit

In three trials, single or multiple doses of citrinin dissolved in 0.5 N-NaOH and adjusted to neutral pH with HCl were given to rabbits by either the oral or intraperitoneal route. The 72-hr LD50 was 50 mg/kg body weight by intraperitoneal administration and 134 mg/kg by the oral route. The primary clinical sign in rabbits receiving a single oral dose of 125-150 mg citrinin/kg was fluid diarrhoea commencing 8 hr after dosing. Pathological alterations were generally confined to the kidney and consisted of degeneration and necrosis of proximal convoluted tubules and straight segments. In rabbits given a single oral dose of citrinin (130 mg/kg) the earliest histopathological change, seen 8 hr after dosing, was cytoplasmic vacuolation of tubular epithelial cells. Rabbits given a single oral dose of 120 mg citrinin/kg had regeneration of renal tubular epithelium accompanied by slight tubular cell necrosis when examined 7 days after dosing. Rabbits given multiple sublethal doses of citrinin (33.5 or 77 mg/kg daily for 7 days) had renal alterations of mild tubular degeneration and necrosis, and tubular regeneration.     

A subacute oral toxicity study of T-2588 in juvenile rats

A subacute toxicity study on T-2588 was carried out in juvenile rats (6 days-old 48 males and 48 females) by oral administrations at dose levels of 250, 500 and 1,000 mg/kg/day for 1 month. The results obtained were summarized below. During the study, there were no clinical signs considered to be related to the treatment. There were no T-2588-related abnormalities in urinalysis, hematological examinations, biochemical examinations and ophthalmological examinations. Slight increases in relative liver and kidney weights were observed in the 1,000 mg/kg-treated group and slight increases in relative kidney weight were detected in the 500 mg/kg-treated female group. Histologically, however, T-2588-related abnormality was not observed. The maximum safety dose of T-2588 was estimated to be 250 mg/kg/day. In addition to the above examinations, male reproductive performance was examined in the group administered with a dose level of 1,000 mg/kg/day. No adverse effects were observed in male fertility and F1 generation.     

Clinical studies on T-2588 in the field of otorhinolaryngology

From clinical studies on T-2588, an oral ester type cephem, the following results were obtained. Ten patients with acute tonsillitis, 3 with acute pharyngolaryngitis, 2 with acute sinusitis, 1 with acute exacerbation of chronic sinusitis and 2 with acute exacerbation of chronic otitis media were treated with T-2588 at a daily dose of 300 or 600 mg. Clinical responses were excellent in 12, good in 4, fair in 1 and poor in 1. Clinical efficacy was 88.9%. Bacteriologically, all isolates except one strain of S. aureus were eliminated. Clinical efficacies classified by clinical isolates correlated well with bacteriological efficacies. The MICs of T-2525 against clinical isolates were determined and compared with those of cephalexin, cefaclor and amoxicillin. The T-2525 showed potent antibacterial activity against Gram-positive and Gram-negative bacteria including S. pneumoniae, H. influenzae and beta-Streptococcus, but the activity of T-2525 against S. aureus was similar to that of the other antibiotics examined. Neither side effect nor abnormal laboratory finding was observed.     

The pharmacokinetics of amlodipine in healthy volunteers after single intravenous and oral doses and after 14 repeated oral doses given once daily.

Intravenous administration of amlodipine (single dose, 10 mg) to 12 volunteers gave a mean plasma half-life of 34 h, mean clearance of 7 ml min-1 kg-1 and a mean apparent volume of distribution of 21 l kg-1. Oral administration (single dose, 10 mg) to the same 12 volunteers gave a mean systemic availability of 64% and a mean plasma half-life of 36 h. In a second study, repeated oral administration (once daily for 14 days, 15 mg) to 28 volunteers resulted in steady state plasma drug concentration being reached after seven doses, an accumulation of approximately threefold and a mean half-life of 45 h.     

Human dose-excretion studies with pyrethroid insecticides cypermethrin and alphacypermethrin: relevance for biological monitoring

1. Dose-excretion studies with cypermethrin (as a 1:1 cis/trans mixture) and alphacypermethrin (one of the two disastereoisomer pairs which constitute cis cypermethrin) were carried out with, in each case, two volunteers per dose level. The studies included (a) single oral alphacypermethrin doses of 0.25 mg, 0.50 mg and 0.75 mg followed by repeated alphacypermethrin doses at the same levels, daily for five days, (b) repeated oral cypermethrin doses of 0.25 mg, 0.75 mg and 1.5 mg daily for five days, and (c) a single dermal application of 25 mg cypermethrin to the forearm. Urine was monitored for the free and conjugated 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid before and after dosing. 2. Metabolism and rate of excretion of a single oral dose of alphacypermethrin was similar to that of cis cypermethrin, on average, 43% of the dose was excreted as the cyclopropanecarboxylic acid in the first 24 h urine. There was no increase in urinary metabolite excretion when alphacypermethrin was administered as a repeated oral dose. Subjects excreted, on average, 49% of the dose as the cyclopropanecarboxylic acid in the subsequent 24 h periods after dosing. 3. There was no increase in the urinary cyclopropanecarboxylic acid excretion when cypermethrin was administered as a repeated oral dose. Subjects excreted, on average, 72% of the trans isomer dose and 45% of the cis isomer dose respectively in the subsequent 24 h periods after dosing. 4. Approximately 0.1% of the applied dermal dose of 25 mg cypermethrin was excreted within 72 h as the urinary cyclopropanecarboxylic acid. No conclusions can be drawn from such urinary excretion data as to the concentration of cypermethrin and its metabolites in the skin or other organs, or the possibility of other routes of metabolism or excretion.     

Nephrotoxicity test on T-3262 in rats with experimental nephropathy

The present study was carried out to examine the effect of orally administered T-3262, a new synthetic antibacterial agent, on the kidney of male rats with experimental nephropathy. These rats had been treated with single intramuscular injection of mercuric chloride (HgCl2, 3 mg/kg) or daily subcutaneous administration of puromycin-aminonucleoside (PAN, 15 mg/kg) for 11 days. T-3262 was administered orally to these pretreated rats at a dose of 1,000 mg/kg/day for 2 or 6 days. Twenty-four hours after the second or the sixth day of T-3262 administration, the kidneys of these rats disclosed similar biochemical and pathological findings as observed in the kidneys of the rats treated with HgCl2 alone. Thus, no T-3262-related alterations were demonstrated in renal functional test, kidney weight or histopathological examinations at a dose of 1,000 mg/kg of T-3262. The HgCl2-induced nephropathy was not enhanced by the oral administration of T-3262. Twenty-four hours after the second or the sixth day of T-3262 administration, the kidneys of the PAN-pretreated rats disclosed the biochemical and pathological findings largely similar to those with PAN-induced nephropathy. Enhancement of PAN-induced nephropathy by the oral administration of T-3262 was hardly evident.     

Influence of food on the oral bioavailability of moxonidine.

Moxonidine is a new centrally acting anti-hypertensive with a very low adverse drug reaction profile. Among others, the aim of the study presented here was to determine the influence of food on the pharmacokinetics of moxonidine. Single oral moxonidine doses of 0.2 mg fasting and 0.2 mg non-fasting were administered in a randomized cross-over study. Eighteen subjects participated in the study, all of whom completed the study according to the protocol. Three sets of analytical plasma data could not be evaluated pharmacokinetically giving a total number of 15 evaluable cases. Renal excretion was evaluated for all 18 subjects. Food intake had no influence on the pharmacokinetics of moxonidine. The relative bioavailability of moxonidine administered under non-fasting conditions reached 94% of the bioavailability after fasted administration. Food intake resulted in a slight decrease of Cmax and a minimal increase of tmax as compared to the fasted treatment. The absorption half-life t1/2a showed a minor prolongation. These differences were not statistically significant in any of the parameters. For t1/2 lambda 2, CLtot and Ae(24h) no statistically significant differences were found between the fasting and non-fasting treatment. The amount of moxonidine excreted unchanged in urine accounted for about 46% of the dose administered after both treatments.     

Pharmacokinetic and pharmacodynamic studies of SK-896, a new human motilin analogue,in healthy male volunteers

OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of SK-896 ([Leu(13)]motilin-Hse) after intravenous administration to healthy male volunteers. DESIGN AND SETTING: This was a non-blinded phase I study.Participants: Thirty male Japanese volunteers (mean age 30.6 years) participated in this study. The volunteers were divided into five groups receiving different doses of SK-896. METHODS: The pharmacokinetics and pharmacodynamics of SK-896 were evaluated after single intravenous infusions of doses of 10, 20, 40 and 80 micro g over 20 minutes to fasting volunteers, or after multiple intravenous infusions (twice a day for 3 days) of doses of 40 micro g over 20 minutes to volunteers in the morning (fasting) and afternoon (non-fasting). Plasma concentrations of immunoreactive SK-896 were determined by radioimmunoassay, and borborygmus was measured as an indicator of drug effect (acceleration of gastrointestinal motility) with an improved Holter electrocardiograph attached to the abdomen. RESULTS: When SK-896 was given by single intravenous infusion at each dose, the plasma concentration of immunoreactive SK-896 rapidly increased to a maximum at the end of the infusion. After the infusion was completed, plasma concentrations declined monoexponentially with an elimination half-time of 4.57-5.64 minutes. The area under the concentration-time curve and the maximum concentration (1.04-9.08 microg-equiv./L) increased in proportion to the dose, and there were no dose-related changes in plasma clearance (7.59-9.34 mL/min/kg), mean residence time (7.83-9.51 minutes) or steady-state volume of distribution (62.9-73.9 mL/kg), indicating that SK-896 plasma concentrations can be described by a linear pharmacokinetic model within the dose range of the present study. After beginning administration, an increase in borborygmus was observed. At doses of 40 and 80 micro g, the borborygmus did not continue even when the plasma concentration was maintained, suggesting that tachyphylaxis occurs at a higher dose. When SK-896 was given as multiple intravenous infusions, the pharmacokinetics did not change with repeated administration. The intensity of borborygmus was low with afternoon administration, reaching only one-third to one-half that with morning administration, suggesting that, like native motilin, SK-896 does not stimulate gastrointestinal motility in the non-fasting state. CONCLUSIONS: The appropriate dose and administration period (fasting or non-fasting) are important factors in stimulating and maintaining gastrointestinal motility when treating gastroparalysis with SK-896.