Fundamental and clinical evaluation of cefozopran in low birth weight infants and neonates

We conducted fundamental and clinical evaluations of a cephem antibiotic, cefozopran (SCE-2787, CZOP), in infants with low birth weights and mature infants. (1) Blood concentrations CZOP was intravenously given in bolus dose of 20 mg/kg to the newborn. The blood antibiotic concentrations were 69.7 micrograms/ml at 30 minutes after administration and the elimination half life was 2.99 hours in mature infants aged 1 to 3 days. They were 38.7 micrograms/ml and 2.85 hours in those aged 4 to 7 days, and 40.8 micrograms/ml and 3.81 hours in those aged 8 days or elder, respectively. In infants with lower birth weights aged 4 to 7 days the blood antibiotic concentrations were 48.6 micrograms/ml at 30 minutes after i.v. administration and the elimination half life was 3.77 hours. The blood antibiotic concentrations at 30 minutes after intravenous doses of 10, 20 and 50 mg/kg in mature infants aged 8 days or elder were 21.1, 40.8 and 153.6 micrograms/ml (value at 60 minutes) and the elimination half lives were 2.24, 3.81 and 3.07 hours, respectively. Administration of CZOP at doses of 20 and 40 mg/kg by intravenous drip infusion over 30 minutes gave the blood drug concentrations of 48.0 and 103.2 micrograms/ml at the end of the infusion and the half lives were 2.60 and 3.33 hours, respectively. (2) Urinary excretion The urinary excretion rates after i.v. bolus doses of 10, 20 and 40 mg/kg were 28.4 to 58.6% of dose. The urinary excretion rate after i.v. drip infusion of 40 mg/kg over 30 minutes was 49.0% of dose. (3) Transfer into cereblospinal fluid The transfer of the antibiotic into cereblospinal fluid in patients with serous meningitis was 4.1 to 15.5 micrograms/ml at 1 hours after administration. (4) Clinical results The clinical efficacy was judged "good" or "excellent" in 2 of the 3 patients with septicemia and in all of the 10 patients with suspected septicemia. It was judged "excellent" in all of the 9 patients with pneumonia, 3 with urinary tract infections and 3 with intrauterine infections. Prophylactic use of the antibiotic was effective in all of the 12 patients. Of the patients in whom bacteriological evaluation was successful, 7 of the 10 causative organisms were confirmed to be eradicated. No adverse drug reactions of signs and symptoms were recognized. Fourteen abnormal alterations of the laboratory test values such as elevation of gamma-GTP and that of GPT were recognized in 8 patients (16.7%). None of them were particularly serious. These results indicate that CZOP is a drug useful for treatment and prevention of infections in infants with lower birth weights as well as in mature infants.     

The association between visual incompetence and spinal derangement: an instructive case history

Dotarizine is a new diphenylmethylpiperazine derivative with Ca2+ channel blocking properties and inhibitory effects on 5-HT2A and 5-HT2C receptors. Previous pilot studies in healthy volunteers demonstrated a good tolerability after single and multiple dosing. Dotarizine appeared to be rapidly and extensively metabolized to an active compound (FI-6020). We aimed to study the physiologic, subjective and psychomotor acute effects of oral dotarizine after single dose administration, to evaluate the tolerability and safety after multiple dosing over 2 weeks, and to study the pharmacokinetic parameters and linearity after single and multiple administration. Two different studies were carried out in 2 groups of 8 healthy male volunteers. Oral single doses of dotarizine 50, 100 and 200 mg were administered in a randomized, double-blind, crossover, placebo-controlled trial. Oral doses of 50 mg twice daily were administered in an open trial over 14 days. Drug effect assessments included vital signs, collection of adverse events, ECG and blood and urine safety evaluations, subjective effects, psychomotor performance tasks and blood sampling. Dotarizine and its metabolite were determined by gas chromatography with N-P detector. The results showed a good tolerability of dotarizine after single oral doses as well as multiple oral doses over 14 days. No clinically relevant adverse events were reported during the study. The highest single dose (200 mg) produced a slight increase in sedation-related symptoms as well as a slight impairment in psychomotor performance tasks. Dotarizine and its major metabolite proved linear kinetics at single doses. The administration of oral doses of dotarizine 50 mg b.i.d. reached the steady state after the 7th day of treatment. The pharmacokinetic parameters remained similar from day 7 to day 14. The terminal elimination half-life of dotarizine and its metabolite appeared to be between 7 and 12 h.     

Pharmacokinetic study of bisaramil in man

Six healthy volunteers received an oral dose of 100 mg and an intravenous dose of 35 mg of bisaramil in a cross over study. Plasma concentrations were measured by HPLC. Bisaramil was eliminated from the plasma with a half life of 8.6 +/- 1.8 h and 9.0 +/- 4.1 h after iv. and oral administration, respectively. The mean total plasma clearance and volume of distribution were found to be 70 +/- 13.1 l/h and 864 +/- 204 l, respectively. The calculated oral bioavailability of bisaramil in tablets amounted to 56 +/- 20%.     

A new method to measure iron absorption from the enrichment of 57Fe and 58Fe in young erythroid cells

Iron absorption can be measured by the incorporation of stable iron isotopes into erythrocytes, 14 days after isotope administration. The disadvantage of this method is the high dose of isotopes needed to obtain a sufficient enrichment. Therefore, in this study cell fractions rich in young erythroid cells were prepared by using a density separation method. From 10 women blood was taken 4, 5, and 7 days after oral and intravenous administration of 57Fe and 58Fe. In these cell fractions and in whole blood taken 14 days after isotope administration, isotope enrichment was measured and absorption calculated. Absorption calculated from the isotope enrichment in the reticulocyte-rich cell fractions (12.2 +/- SEM 3.7%) was not significantly different from absorption based on whole-blood values (13.0 +/- 3.3%). Because a threefold higher isotope enrichment was found in the cell fractions, the required dose of stable isotopes can be reduced to one-third of the dose used in the traditional method without loss of sensitivity.     

Concentration of cardiac glycosides in the heart and brain (author's transl)

In cats the concentration of cardio-active glycosides in the heart and brain were investigated with trititum-labelled substances. Steady-state conditions were achieved by repeated i.v. injections of ouabain, digoxin, beta-methyldigoxin, digitoxin, and oleandrin over 5 days. 5 h after the last application glycoside concentrations were measured in plasma, urine, heart, cerebrum and cerebellum. Furthermore the metabolic pattern in these compartments was determined. 1. The glycoside concentration in the heart per g wet weight ranges only from 0.93 (oleandrin) to 1.88% (ouabain) of the daily administered dose per kg. 2. The concentrations in the brain show much higher differences between the diverse glycosides: ouabain with a concentration of 0.02%/g wet weight in the cerebrum shows the lowest and oleandrin with 1.60% the highest value. 3. By calculating the mean relative weights for the hearts (3.9 g/kg) and the brains (11.1 g/kg) 3.7% of the daily administered ouabain activity were found in the whole heart and only 0.18% in the whole brain. In contrast to these data the content of heart and brain after giving the more lipophilic oleandrin was 3.6% and 17.7% (!), respectively. 4. Under steady-state conditions the glycosides ouabain, digoxin, beta-methyldigoxin and digitoxin in heart and brain are mainly unchanged whereas oleandrin is transformed at a higher rate to polar metabolites.     

Differential induction of prehepatic and hepatic metabolism of verapamil by rifampin

Cytochrome P450 (CYP) enzymes, which metabolize numerous drugs, are expressed both in liver and in extrahepatic tissues. CYP3A4 for example is present and inducible by rifampin in epithelial cells of the gastrointestinal tract. It has been shown that such prehepatic metabolism contributes substantially to total clearance of CYP3A4 substrates (e.g., cyclosporine) before and even more pronounced during enzyme induction. We examined the effect of enzyme induction on prehepatic and hepatic metabolism of the model compound R/S-verapamil after simultaneous oral and intravenous administration using a stable isotope technology. This approach allows us to exclude intraindividual day-to-day variability and is therefore suitable to quantitatively assess prehepatic extraction of high-clearance drugs. Moreover, because verapamil is administered as a race-mate with the S-enantiomer being preferentially metabolized, we investigated the influence of induction on stereoselectivity of prehepatic and hepatic metabolism. Eight male volunteers received 120 mg of racemic verapamil bid for 24 days. Rifampin (600 mg daily) was given from day 5 to day 16. Systemic clearance and bioavailability of the verapamil enantiomers were determined by coadministering deuterated verapamil intravenously on day 4, on day 16, and on day 24. Effects of verapamil on atrioventricular conduction after oral and intravenous (iv) administration were assessed by measuring the maximum PR-interval prolongation Rifampin increased the systemic clearance of the active S-verapamil 1.3-fold (P < .001). In contrast, rifampin increased the apparent oral clearance of S-verapamil 32-fold (P < .001) and decreased its bioavailability 25-fold (P < .001), with partial recovery after rifampin withdrawal (P < .01). With rifampin, the effect of oral verapamil on atrioventricular conduction was nearly abolished (P < .01), whereas no significant changes were observed after intravenous administration. Induction caused a considerable reduction of stereoselectivity after both intravenous and oral administration (P < .001). Rifampin altered the pharmacokinetics and the pharmacological effects of verapamil to a much greater extent after oral administration compared with intravenous administration. These data clearly indicate that prehepatic metabolism of verapamil (presumably in the gut wall) is preferentially induced compared with hepatic metabolism and that stereoselectivity of verapamil metabolism is affected by induction.     

Metabolism and biochemical effects of 3,3',4,4'-tetrachlorobiphenyl in pregnant and fetal rats

The metabolism and distribution of a single oral dose of 25 mumol 14C-labelled 3,3',4,4'-tetrachlorobiphenyl (14C-TCB) were investigated in pregnant female Wistar rats and their fetuses. TCB was administered on day 13 of gestation and the elimination was followed for 7 days. Non-pregnant rats were treated similarly for comparison. Fecal elimination of 14C-TCB derived radioactivity was significantly lower in pregnant rats than in non-pregnant rats. The major metabolite found in adult liver and plasma, placental tissue, whole fetuses and fetal plasma was 3,3',4',5-tetrachloro-4-biphenylol (4-OH-TCB). Tissue levels (liver, abdominal fat, skin, skeletal muscle, kidney and plasma) of 14C-TCB-derived radioactivity declined by 65-85% over a 7-day period following administration in the adult animals. However, 14C-TCB-derived radioactivity accumulated more than 100-fold in the fetuses over the same time period, and GC/MS analysis revealed that the fetal accumulation in radioactivity was due primarily to 4-OH-TCB, and not the parent compound. On day 20 of gestation, concentrations of 4-OH-TCB were 14 times greater in fetal plasma than maternal plasma. Treatment with 14C-TCB significantly reduced plasma thyroxine levels by at least 28% up to 7 days after administration in non-pregnant animals and up to 4 days after administration in pregnant rats (31% decrease). By 7 days after administration plasma thyroxine levels had returned to control levels in the TCB-treated pregnant rats. However, fetal plasma thyroxine levels were significantly decreased by 35% in fetuses from 14C-TCB-treated dams 7 days after TCB administration. Hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity was significantly induced in TCB-treated dams relative to controls at 4 and 7 days after administration, while no EROD activity was detected in hepatic microsomes from control or TCB treated fetal rats at day 20 of gestation. These data suggest that hydroxylated metabolites of polychlorinated biphenyls may play a role in the development toxicity of these compounds.     

Natural resistance to Marek''s disease at hatching in chickens lacking maternal antibody, and relationship between this early resistance and resistance acquired with age

A double-blind cross-over trial was conducted with 20 healthy paid volunteers for the evaluation of the subacute effects of chlorpromazine (CPZ) and sulpiride, in oral doses used for anxious outpatients, on psychomotor skills related to driving. Psychomotor performance was measured on the 7th and 14th days of treatment at 30, 90 and 150 min after the intake of 0.5 g/kg of an alcoholic or placebo drink. After the neuroleptics alone, reaction and coordination skills, but not attention, were slightly impaired, CPZ differing significantly from the placebo on the 14th day. Both drugs interacted additively with alcohol. The combined administration of CPZ and alcohol led to inaccuracy, a slowing of reactions and impaired proprioception and coordination. The combination of sulpiride and alcohol increased the error rate in the choice reaction test and impaired coordination in the coordination test driven at a free speed. It is concluded that the psychomotor decrement that occurs after 2 weeks of treatment with small doses of CPZ may effect the ability to control a motor vehicle. The concurrent administration of alcohol during treatment with CPZ or sulpiride may cause some extra risk in traffic or occupational life.     

A pharmacokinetic study of intravenous itraconazole followed by oral administration of itraconazole capsules in patients with advanced human immunodeficiency virus infection

A randomized, open-label, comparative study was conducted in 30 male patients with moderately advanced human immunodeficiency virus (HIV) infection to examine the pharmacokinetics of an investigational intravenous preparation of itraconazole compared with pharmacokinetics after administration of itraconazole capsules. The study also assessed whether adequate plasma concentrations of itraconazole could be rapidly achieved with the intravenous formulation and then maintained after cessation of intravenous therapy with itraconazole capsules. All patients received 200 mg intravenous itraconazole as a 1-hour infusion in 40% hydroxypropyl-beta-cyclodextrin (HP-beta-CD) vehicle twice daily for 2 days, and then 200 mg intravenously once daily for 5 days. Patients then received itraconazole capsules, either 200 mg twice daily or 200 mg once daily for 28 days. Steady-state plasma concentrations of itraconazole were reached by day 3 with intravenous infusion, a much shorter time than observed with administration of itraconazole capsules. Steady-state concentrations of itraconazole and hydroxyitraconazole were effectively maintained during the rest of the intravenous infusions of itraconazole. Oral follow-up with administration of 200-mg capsules once daily could not maintain the plasma concentrations of itraconazole and hydroxyitraconazole obtained at the end of the intravenous treatment, whereas twice-daily oral administration maintained or increased these concentrations. Mean plasma concentrations of itraconazole and hydroxyitraconazole on day 7 were similar to those on day 36 in the twice-daily group. Mean renal clearance was comparable to mean total body clearance, and approximately 93% to 101% of the HP-beta-CD was excreted unchanged in urine within 12 hours of administration. The HP-beta-CD was essentially eliminated through the kidney, and little accumulation in the body was observed in this patient population. Adverse events during the intravenous phase were most commonly associated with intravenous administration. Intravenous infusion of itraconazole for 7 days followed by administration of itraconazole capsules twice daily for 28 days is an effective dose regimen in patients with advanced HIV infection.     

Absorption, distribution, and excretion of [14C]patulin by rats

Adult rats of both sexes were given a single oral dose of [14C] patulin and were sacrificed at various time intervals from 4 hr to 7 days following administration of the mycotoxin. Two groups of rats were employed; the treated group had been exposed to daily oral doses of unlabeled patulin (dissolved in pH 5.0 citrate buffer) in utero and for 41-66 wk after weaning, while the controls were given the buffer only throughout gestation and for 38-81 wk after weaning. Approximately 49% of the administered 14C radioactivity was recovered from feces and 36% from urine within 7 days after dosing. Most of the excretion of labeled material occurred within the first 24 hr. All of the 14C activity detected in the urine samples was either metabolites and/or conjugates of the original [14C]patulin. About 1-2% of the total radioactivity was recovered as 14CO2 from expired air. Carbon-14 radioactivity in various tissues and organs was determined throughout the 7 day period; the most significant retention site was the red blood cells.     

Road traffic mortality in Victoria: an exploratory investigation into successful strategies

The recovery of radioactivity from plasma, urine and feces was determined in rats after administration of oral and intravenous doses (200 mg/kg) of 14C-labeled sodium gamma-hydroxybutyric acid. Very small portions of the radioactive dose were recovered in the urine (5.5%, oral; 7.1%, intravenous) and feces (1.5% oral; 0.6%, intravenous) collected between 0-48 hours after drug administration. Considerable levels of radioactivity were found in the plasma after oral dosing. The area under the plasma radioactivity time curve after an oral dose was found to be 65% of that observed after an equivalent intravenous dose. This value is much larger than the relative area value (8%) calculated on the basis of free gamma-hydroxybutyric acid. Results of this study strongly indicate that first-pass metabolism, rather than lack of absorption, is responsible for the apparently poor oral bioavailability of gamma-hydroxybutyric acid.     

Tau in Alzheimer''s disease

The effects on goats of Calotropis procera latex given by different routes of administration were investigated. The administration of latex at 1 ml/Kg body weight via the oral route or at 0.005 ml/Kg body weight/day via the intravenous or intraperitoneal route caused death of the goats between 20 minutes and 4 days. When the small dose of latex (0.005 ml/Kg body weight/day) was given by the oral route or intramuscular route no death among the goats occurred. Nervous signs, frequent urination, frothing at the mouth, dyspnoea and diarrhoea were the main features in goats given latex by the oral, intravenous or intraperitoneal route. Lameness was observed in goats given latex via the intramuscular route. Lesions were widespread congestion and haemorrhage, pulmonary cyanosis, enterohepatonephropathy, peritonitis (in goats receiving latex via i.p. route) and haemorrhagic myositis at the site of latex injection. These changes were accompanied by increases in the activities of serum GDH, LDH, ALP, GGT and AST and in the concentrations of cholesterol, urea and creatinine and decreases in the level of total protein.     

Clinical findings of cefoxitin in the treatment of serious infections and the prevention of postoperative infections (author''s transl)

This clinical trial was designed to evaluate the efficacy, safety and patient tolerance of cefoxitin in 23 patients who were admitted to the hospital from March 1980 to November 1980. The daily dose of cefoxitin for 21 adult patients (ages ranged from 26 to 74 years old) were 6 g for the treatment of infections, and 2 to 6 g for the prevention of infections by either direct or intermittent intravenous infusions. Two children were given 100 mg/kg of cefoxitin either by direct or intermittent intravenous infusions 2 to 3 times a day in divided doses. Summary of findings: I. Treatment of intracranial infections 1. A 60-year-old man with a brain abscess was admitted to the hospital after the unsuccessful treatment with a cephalothin for 9 days. After, the initiation of therapy with cefoxitin, given 6 g a day for 3 days, the abscess was surgically removed. On the second day of treatment with cefoxitin following the operation, his highest temperature was 37.0 degrees C and was normal on the third day of treatment. He was discharged after 12 days after the surgical procedure. 2. A 56-year-old woman with cerebrospinal rhinorrhea and meningitis after the transsphenoidal removal of pituitary microadenoma responded satisfactorily to therapy with cefoxitin, given 6 g a day for 14 days after the unsuccessful treatment with a cephalothin. II. The prevention of infections following surgical operation of the central nervous system 1. Seventeen patients undergoing surgical procedures were treated with cefoxitin for the prevention of postoperative infections. None of the 17 patients developed postoperative infections. 2. A 53-year-old man undergoing repair of cerebrospinal rhinorrhea in the possibly contaminated area was successfully treated with cefoxitin, given intravenous 2 g every 8 hours for 10 days without meningitis having developed. III. The treatment and prevention of complications 1. A 74-year-old comatose male with a brain stem concussion, who was expectorating insufficiently and had difficulty swallowing and developed into pneumonia as a complication. He was successfully treated with cefoxitin, given intravenous 6 g a day for 2 weeks. 2. A 26-year-old male with a brain stem concussion complicated by pneumonia and a urinary tract infection was successfully treated with the same dose regimen of cefoxitin as the previous patient. 3. The prevention of complications A 58-year-old male with pontine glioma undergoing a tracheotomy was administered cefoxitin for the prevention of pulmonary complication. He died of pontine glioma after the three-month treatment. IV. Side effects Results of skin sensitivity tests given prior to the administration of cefoxitin were negative in all of the 23 patients. Neither anaphylaxis nor other allergic reactions or thrombophlebitis occurred with the intravenous administration of cefoxitin. No abnormalities in blood, hepatic function or renal function were observed. Anorexia occurred in 1 patient who was given cefoxitin, 6 g a day.     

Bioavailability and pharmacokinetics of cyproterone acetate after oral administration of 2.0 mg cyproterone acetate in combination with 50 micrograms ethinyloestradiol to 6 young women

The bioavailability and pharmokinetics of cyproterone acetate (CA) were studied in 6 healthy young women. The subjects received a single oral dose of 2 mg carbon-14-CA plus 50 mcg tritiated-ethinyl estradiol. Matimum plasma levels of CA were observed about 4 hours after administration. During the 4-10 hours following administration, carbon-14-CA in plasma disappeared with a half-life of 3 + or -1.6 hours. The half-life for the subsequent phase of disposition was 1.7 + or -.5 days. The apparent volume of distribution for CA was 1300 + or -580 liters. Although plasma equivalents of carbon-14-CA had higher absolute values, the course of their distribution was similar to those concentrations for the unchanged drug. 88 + or -11% of the dose was recovered and 30.4 + or -7.3 excreted in urine. The concentration of the primary metabolite of CA in plasma showed a decline which paralleled the terminal disposition phase of CA; the elmination half-life being 1.8 + or -.1 days. The apparent distribution volume for the primary metabolite was 95 + or -25 liters. CA, in comparison with its primary metabolite, had 10 times the apparent distribution volume. Approximately 90% of CA was present at all times following administration. In terms of total activity, the proportion of CA in plasma remained constant 1/2 day after administration. It is suggested that the transfer of CA from tissues determines the rate of metabolization of CA and the excretion of metabolites.     

Effects of alcohol on eating behavior: influence of mood and perceived intoxication

A 45-year-old male who had looked over pet-birds at a bird shop 11 days before, developed a high fever with chills. Without any response to cephalexin, he was admitted to the hospital, with the chief complaints of high fever and sever headache on the 8th day of illness. The chest X-ray films taken then revealed a fun-shaped ground glass-like shadow extending over S10 of the right lung. After the oral administration of 450 mg rifampicin on the 9th day of illness, he became a febrile within one day and was cured with the same daily doses for the following 10 days. Chlamydia was isolated from the peritoneal exudate of the mice inoculated with throat mucus of the patient taken prior to the administration of rifampicin. Complement fixation reaction for psittacosis was positive in a titer of 1 : 16 on the 11th day of illness and rose to 1 : 64 in a week.     

Pharmacokinetics of single intravenous and oral doses of dolasetron mesylate in healthy elderly volunteers

Dolasetron mesylate (MDL 73,147EF, Anzemet; Hoechst Marion Roussel, Laval, Canada) is a 5-HT3 receptor antagonist undergoing clinical evaluation for use as an antiemetic agent. The pharmacokinetics of dolasetron and its reduced metabolite (MDL 74,156) were studied after administration of single intravenous and oral doses of dolasetron mesylate 2.4 mg/kg in 18 healthy elderly subjects. Expressed as the dolasetron base, this dose was 1.8 mg/kg. Dolasetron was rapidly metabolized to the reduced metabolite, which appeared in plasma within 10 minutes after intravenous or oral administration. The mean half-life (t1/2) of dolasetron was 0.24 hours after intravenous administration and 0.50 hours after oral administration. The pharmacokinetic parameters of the reduced metabolite were similar after intravenous and oral administration. The apparent absolute bioavailability of the reduced metabolite was 89%, and it had an elimination t1/2 of approximately 7 hours and an apparent volume of distribution (Vd beta) of 4.69 L/kg. Dolasetron was not detected in urine. Metabolites were excreted in urine almost completely within 24 hours of administration. The primary metabolite detected in urine was the (+)-enantiomer of the reduced metabolite, which accounted for 25.35% (+/- 7.79%) and 18.88% (+/- 7.65%) of the intravenous and oral doses, respectively. Hydroxylated metabolites accounted for 5% or less of the total dose via either route. The pharmacokinetics of the reduced metabolite after single intravenous or oral doses in elderly volunteers were consistent with pharmacokinetics observed in both young healthy men and cancer patients receiving high-dose cisplatin chemotherapy. Dosage adjustments of dolasetron mesylate on the basis of age do not appear to be necessary.     

Cyclosporin for the treatment of severe ulcerative colitis

The effect of cyclosporin was evaluated in six patients with severe ulcerative colitis not responding to at least 8 days of standard therapy with intravenous corticosteroids. Cyclosporin (5-7.5 mg/kg/day intravenously) was added while steroid therapy was continued. Five of 6 patients responded after a mean of 7 days and colectomy was not necessary. After 4 weeks three patients achieved clinical remission or had mild symptoms and were weaned from cyclosporin and corticosteroids without exacerbation within the next 7-15 months. Two patients improved and they were put on oral cyclosporin. One of them relapsed after 2 weeks and then responded to high dose corticosteroids. This patient is doing well at 8 months of followup on azathioprine and steroids. One patient stopped oral cyclosporin after 3 months abruptly and then had a relapse. He subsequently improved while refusing any medical therapy. Side effects of cyclosporin occurred in 2 patients but were mild and self limited and did not necessitate discontinuation of the drug. Cyclosporin appears to be effective in a large portion of patients with severe ulcerative colitis who failed to improve on corticosteroids and in whom colectomy would otherwise be considered.     

Absorption, pharmacokinetics and metabolism of 14C-sumatriptan following intranasal administration to the rat

1. Studies have been carried out to investigate the absorption of sumatriptan after intranasal administration to rats. The pharmacokinetics, metabolism and excretion of 14C-sumatriptan were compared following intranasal and intravenous dosing to male and female albino rats using an aqueous buffered formulation at pH 5.5. 2. Following intravenous administration sumatriptan was eliminated from plasma with a half-life of about 1.1 h. After intranasal administration there was rapid absorption of part of the dose and two peak plasma concentrations were observed, initially at 0.5 and then at 1.5-2 h. The elimination half-life after the second peak was estimated as being about 4 h. 3. Radioactivity was largely excreted in urine (up to 89% of dose in 168 h) after both intravenous and intranasal administration, with a faster rate of excretion after intravenous dosage (73% males, 64% females within 6 h) than after intranasal dosage (37% males, 40% females within 6 h). 4. 14C-sumatriptan was the major component in urine and in extracts of faeces after both intravenous and intranasal administration. The major metabolite excreted in urine and faeces was GR49336, the indole acetic acid analogue. 5. The results of this in vivo rat study suggest that absorption of the dose via the nasal mucosa is incomplete after intranasal administration and that there is a secondary absorption phase probably reflecting oral absorption of part of the dose. The bioavailability is estimated as about 30%, for the period 0-6 h.     

Metabolism of oral contraceptive drugs. The formation and disappearance of metabolites of norethindrone and mestranol after intravenous and oral administration

Previous studies from this laboratory reported that 3H-labeled metabolites with half-lives of more than 24 hours may remain in the plasmaa of women receiving an intravenous injection of 3H norethindrone or 3H mestranol. To confirm the presence of these metabolites, blood samples were collected for five days after injection of 3H norethindrone or 3H mestranol; 3H representing metabolites of norethindrone disappeared with half-life values of 42 to 84 hours (mean 67 hours), while 3H representing metabolites of mestranol declined with an average half-life of 45 hours (range 37 to 65 hours). When the 3H-labeled drugs were administered orally, metabolites of similar half-life were formed. Because these compounds exist for several days after a single administration and since oral contraceptive drugs are normally taken daily, the possiblity of the accumulation of 3H in the plasm of women receiving several consecutive doses of 3H norethindrone was investigated. The results of this study show a stepwise accumulation of the 3H metabolites when 3H norethindrone was administered in six daily oral doses. However, the 3H levels declined from the peak on the sixth and last day of the treatment at a rate equivalent to those previously measured after intravenous or oral administration.     

Disposition of phenol in rat after oral, dermal, intravenous, and intratracheal administration

The absorption and elimination of [14C]-phenol (63.5 nmol) after oral, dermal, intratracheal, or intravenous administration in rat was rapid and extensive. Urinary elimination of radioactivity predominated, with a range of 75-95% of the dose detected in urine by 72 h post-exposure. Washing the dermal site 72 h post-exposure removed 14% of the dose. Two per cent of the dose was detected in the skin. The urinary metabolites at 4 and 8 h after administration by the four routes included phenyl sulphate and lower amounts of phenyl glucuronide. Phenol was poorly retained in the body after administration by the four routes. Phenol remaining in the body was widely distributed, with accumulation primarily in the liver, lung, and kidney.