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H S Weintraub

Publications and source records attributed to H S Weintraub.

16 recordsLinked to original sources
PubMed1988

Comparative bioavailability of suprofen after coadministration with food or milk.

Suprofen is a nonsteroidal analgesic with demonstrated efficacy in the treatment of mild to moderate pain associated with a variety of clinical conditions. Because nonsteroidal analgesic agents may cause gastrointestinal side effects, they are frequently prescribed with food or milk. The purpose of this study was to evaluate the effects of a standard meal and milk alone on the rate and extent of absorption of suprofen. In a randomized three-way cross-over study, 24 healthy volunteers each received a single 200-mg oral dose of suprofen in the fasted state half an hour after a standard meal or half an hour after an 8-ounce glass of milk. The influence of food and milk was greater on the rate than on the extent of absorption of suprofen as illustrated by a more pronounced effect on Cmax than on AUC. In addition, food had a greater influence on the bioavailability of suprofen than milk. Food decreased the mean Cmax to 44% and the mean AUC to 81% relative to the fasted state, whereas milk decreased the mean Cmax to 74% and the mean AUC to only 87% of the respective parameters in the fasted state. Symmetrical confidence intervals demonstrated that the mean AUCmilk was within only 19% and the mean AUCfood was within only 25% of the mean AUC in the fasted state, with 95% confidence.

Adult↗
PubMed1988

Single-dose and multiple-dose pharmacokinetics of etintidine in healthy volunteers.

The present study was designed to determine the single- and multiple-dose pharmacokinetic profiles of the H2 receptor antagonist etintidine in healthy volunteers. Etintidine was rapidly absorbed and eliminated after the oral administration of 300 mg base equivalent of etintidine HCl in a capsule formulation to 11 healthy subjects. Comparison of the pharmacokinetics after a single dose and during steady state showed no significant differences (p greater than 0.05) in the mean values of Cmax, tmax, oral clearance, elimination rate constant, and renal clearance, indicating no significant accumulation of etintidine and no apparent time-dependent changes in the pharmacokinetics of etintidine during multiple dose administration.

Absorption↗
PubMed1988

The effect of food or milk on the bioavailability of etintidine in healthy subjects.

A three-way crossover study was conducted in 24 normal, male volunteers to compare the bioavailability of etintidine from capsules (2 X 200 mg) taken under fasting conditions, with food and with milk. Blood samples were collected prior to and at various times after each treatment and plasma levels of etintidine were determined by high performance liquid chromatography. Statistical analysis of the plasma etintidine concentration data indicated that while neither food nor milk had an apparent effect (p greater than 0.05) on the rate of etintidine absorption, both food alone and milk alone slightly decreased the extent of etintidine absorption. Mean bioavailability parameters of etintidine obtained following the administration of etintidine with food, milk or under fasting conditions are 5.28, 5.26 and 5.88 micrograms.h/ml, respectively (for AUC) and 1.75, 2.18 and 2.59 micrograms/ml, respectively (for Cmax), and 1.23, 1.01 and 0.91 h, respectively (for tmax). Symmetrical 95% confidence interval analyses showed that the observed decreases of less than 11% in the AUC values of etintidine following the concomitant administration of food or milk were within 17% of the fasting value and, therefore, may not be of clinical significance.

Adolescent↗
PubMed1987

Etintidine-propranolol interaction study in humans.

Etintidine HCl is a potent H2-blocker. The effect of clinical doses of etintidine on the disposition of a single oral dose of propranolol was investigated in 12 normal subjects. This was a double-blind, two-way crossover study. Each subject received etintidine (400 mg) or placebo twice a day with meals for 4 days on two occasions (separated by 4 days). On each occasion, the subjects were fasted overnight on Day 3 and were given an oral dose of Inderal (40 mg propranolol hydrochloride) 30 min following the administration of the morning dose of etintidine or placebo on Day 4. Blood samples were collected prior to and up to 24 hr following the administration of propranolol. The plasma samples were analyzed for propranolol and 4-hydroxypropranolol by HPLC. Comparison of the pharmacokinetic parameters of propranolol between etintidine and the placebo groups indicates that etintidine significantly increased the AUC0-infinity values (573.5 vs. 146.4 ng.hr/ml, p = 0.0001) and prolonged the elimination half-life (4.61 vs. 2.33 hr) of propranolol. Statistical evaluation of the pharmacokinetic parameters of 4-hydroxypropranolol indicates that etintidine also increased the AUC0-24 values (43.8 vs. 16.4 ng.hr/ml, p = 0.0028) and prolonged the elimination half-life (4.87 vs. 1.97 hr) of 4-hydroxypropranolol. The data suggest that etintidine, like cimetidine, impaired the elimination of propranolol. Etintidine also protracted the elimination of 4-hydroxypropranolol, an active metabolite of propranolol.

Adolescent↗
PubMed1982

Bromperidol, a new butyrophenone neuroleptic: a review.

This review compares and contrasts the preclinical pharmacology of bromperidol with another butyrophenone neuroleptic, haloperidol, and the phenothiazine neuroleptic chlorpromazine. Its pharmacokinetics, biotransformation, and safety in several laboratory animal species are also summarized. These preclinical data support its use as an antipsychotic agent and show that it is well absorbed following oral administration with an apparent elimination half-life of approximately 24 h, supporting a once-daily dose regimen. Animal toxicity (including acute- and multiple-dose toxicology and reproductive and mutagenicity studies) show that bromperidol is well tolerated.

Animals↗
PubMed1979

Human pharmacokinetics and comparative bioavailability of loperamide hydrochloride.

A pharmacokinetic study of the antidiarrheal agent loperamide hydrochloride (Imodium) was conducted in six male subjects. The study utilized a random crossover design and employed a 2-mg capsule and a 0.2-mg/ml syrup formulation. Each treatment consisted of a single oral dose of 8 mg loperamide HCl followed by a two-week interval before the next treatment. Serum and urine samples obtained at various times after drug administration were assayed for loperamide using a radioimmunoassay specific for the drug. The mean biologic half-life, calculated from the elimination phase of the log serum concentration-versus-time data, was 10.8 +/- 0.6 hours for the overall study, 10.2 +/- 0.6 hours for the syrup formulation, and 11.2 +/- 0.8 hours for the capsules. The loperamide from the syrup was absorbed more rapidly than from the capsule formulation, with the peak serum levels observed at a mean time of 2.4 +/- 0.7 hours for the syrup and 5.2 +/- 0.3 hours for the capsule formulation. The relative areas under the serum loperamide concentration-versus-time curves suggested that the two formulations have comparable physiologic availability. The maximum observed serum concentrations were also similar, indicating the safety of the syrup formulation. Excretion of approximately 1 per cent of the dose in the urine as unchanged loperamide after seven days was observed independent of the particular dosage form that was administered.

Adult↗
PubMed1979

Short in vitro half-life of thymopoietin32--36 pentapeptide in human plasma.

Thymopoietin32--36 (TP5) is a synthetic pentapeptide that has the biological activity of its parent molecule, the 49 amino acid thymic hormone thymopoietin. Tritiated thymopoietin32--36 (3 /-TP5) was prepared by reductive tritiation of dibromotyrosyl-TP5. The stability of 3 H-TP5 in human plasma was studied by analyzing samples by thin-layer chromatography at different time points and quantitating the radioactivity associated with TP5 (Arg-Lys-Asp-Val-Tyr) and its tyrosyl-containing breakdown products (Lys-Asp-Val-Tyr, Asp-Val-Tyr, Val-Tyr, Tyr). In plasma (but not in saline) the pentapeptide was rapidly degraded (apparent t1/2 approximately 30 seconds) with the corresponding appearance of radioactivity associated with the other tyrosyl-containing reference compounds. These data imply that the pentapeptide, which is active in vivo, may rapidly trigger changes in responsive cells; sustained circulating levels may not be required for activity.

Adult↗
PubMed1978

Comparative bioavailability of a lipophilic steroid.

17beta-Acetoxy-2alpha-chloro-3-(p-nitrophenoxy)imino-5alpha-androstane (I) is a lipophilic steroid with postimplantive antifertility activity in laboratory animals. The bioavailability of micronized I from solutions and suspensions was compared in four groups of adult female Wistar rats. Each group received varying concentrations of micronized 3H-I (specific activity of 0.38--8.94 muCi/mg) in sesame oil by oral gavage. Samples of whole blood and urine collected following drug administration were assayed for radioactive content. Calculation of the mean area under the blood radioactivity versus time curve, when corrected for the quantity of drug administered, indicated that a substantially larger fraction of the dose was absorbed in the two instances where I was present only in solution. A linear relationship between the amount of I absorbed based on whole blood radioactivity and urinary excretion and the administered dose was found primarily for groups receiving the drug in solution. Preliminary results in humans indicate that 3H-I was absorbed to a much greater extent following oral administration of the drug in sesame oil than when admixed with lactose.

Abortifacient Agents↗
PubMed1978

Disposition of norgestimate in the presence and absence of ethinyl estradiol after oral administration to humans.

The disposition of radioactivity following oral administration of 14C-norgestimate was compared to that following administration of the drug in combination with 3H-ethinyl estradiol in humans. Seven normal, healthy female subjects were each administered one capsule orally containing 14C-norgestimate either alone (74.4 muCi, 0.50 mg) or in combination (73.5 muCi, 0.49 mg) with 3H-ethinyl estradiol (103 muCi, 0.14 mg) in polyethylene glycol 400. Peak levels of radioactivity due to carbon-14 and tritium in plasma occurred within 2 hr after drug administration, followed by distribution and elimination phases. The mean apparent elimination half-life and mean cumulative elimination of radioactivity in the urine and feces following 14C-norgestimate administration were not significantly different than those following administration of the combination dose. Approximately 50% of the administered radioactivity due to carbon-14 was excreted in the urine following administration of 14C-norgestimate both in the presence and absence of coadministered 3H-ethinyl estradiol.

Administration, Oral↗
PubMed1978

Disposition of ORF 9326, a novel contragestational steroid, in animals.

The disposition of ORF 9326 [17BETA-acetoxy-2alpha-chloro-3(p-nitrophenoxy) imino-5-androstane], an O-aryl oxime of 2beta-chlorodihydrotestosterone acetate, was studied in rats, dogs, monkeys and rabbits. Intravenous administration of 3H-ORF 9326 dissolved in PEG-400 to rats, dogs and monkeys resulted in a rapid decline of radioactivity in blood followed by a terminal slope suggesting long retention of radioactivity. Apparent half lives of radioactivity in blood were calculated to be from 50--95 hours for the three species, which peak levels of radioactivity in whole blood occurring within 4--7 hours after administration of the compound. Tissue distribution studies in the rat and dog indicate that body fat is one of the major depot areas for the drug and/or its metabolites. The major route of excretion for ORF 9326 and/or its metabolites in dog and rat is biliary whereas in monkey and rabbit it appears to be renal. Greater than 90% of the radioactive compounds excreted in the urine of dogs and monkeys following intravenous administration of 3H-ORF 9326 appear to be in the form of conjugates.

Abortifacient Agents↗
PubMedDate not supplied

Etintidine-theophylline interaction study in humans.

Etintidine HCl is a potent H2-blocker. The effect of clinical doses of etintidine on the disposition of theophylline was investigated in 10 male volunteers. This was a double-blind, two-way crossover study. Each subject received etintidine (400 mg) or placebo twice a day with meals for 4 days on two occasions (separated by 4 days). On each occasion, the subjects were fasted overnight on Day 3 and were given an oral dose of theophylline elixir (5 mg/kg) 30 min following the administration of the morning dose of etintidine or placebo on Day 4. Blood samples were collected prior to and up to 24 h following the administration of theophylline. Plasma theophylline levels were analysed by HPLC. Theophylline was rapidly absorbed following oral administration of the theophylline elixir to both the placebo and etintidine treatment groups. Comparison of the pharmacokinetic parameters of theophylline between the etintidine and the placebo groups indicates that while etintidine did not significantly (p greater than 0.05) affect the apparent Cmax (11.1 vs 10.0 micrograms ml-1) and Tmax (1.7 vs 1.4 h) values of theophylline, etintidine significantly reduced the oral clearance (0.0200 vs 0.0564 l kg-1 h-1, p = 0.000006) and prolonged the elimination half-life (16.8 vs 6.0 h) of theophylline. The data indicate that etintidine, like cimetidine, extended the elimination of theophylline in humans.

Administration, Oral↗
PubMedDate not supplied

Pharmacokinetics and bioavailability of etintidine in beagle dogs: effects of routes of administration, doses, dosage forms, and chronic dosing.

Etintidine HCl is an H2 receptor antagonist which has been under clinical trial for the treatment of duodenal ulcer diseases. Our studies are to determine the effects of routes of administration, doses, dosage forms, and chronic dosing on the bioavailability and pharmacokinetics of etintidine (E) in the beagle dog. Salient findings are: 1. Plasma levels of etintidine after i.v. administration of 200 mg of E followed a 3-exponential decay with a terminal t1/2 of 1.7h. 2. Following oral administration of 200 mg of E in capsules, tablets, or a solution dosage form to dogs, etintidine was rapidly and nearly completely absorbed with no significant first-pass elimination. 3. A proportional increase in the amount of etintidine absorbed in the dogs occurred as the administered doses increased from 30 to 180 mg kg-1 and this relationship did not change with repeated dosing. 4. Some accumulation of etintidine took place during the 52 weeks of chronic dosing.

Administration, Oral↗
PubMedDate not supplied

Clinical pharmacokinetics of etintidine.

The pharmacokinetics of etintidine (E), a potent H2 blocker, were studied in 12 normal, fasted subjects. The subjects received five ascending doses of E HCl in capsules at 72-h intervals. Blood and urine samples were collected and the plasma and urine levels of E were determined by HPLC. Following oral administration, plasma E levels showed double peaks in half of the subjects. Mean Cmax (0.42, 2.11, 3.82, 4.50, and 7.15 micrograms ml-1), AUC0-infinity (0.96, 4.94, 11.3, 17.5, and 24.5 h micrograms ml-1), and the amount of E excreted unchanged in 72 h (20, 54.8, 170, 320, and 371 mg) were determined. These parameters indicate the amount of E absorbed increased linearly with dose for each individual. Renal clearance was independent of the dose and the mean value (16.6 lh-1) was about twice that of the creatinine clearance (which did not significantly change as a result of E treatment), indicating that E is actively secreted into the renal tubules. As E was eliminated rapidly from the body (t1/2 less than 2 h), no substantial accumulation of E is expected after multiple dose treatment.

Administration, Oral↗
PubMedDate not supplied

Pharmacokinetics of tinidazole in male and female subjects.

Tinidazole is a potent nitroimidazole compound active against, and used to treat, Trichomonas vaginalis infections in males and females. Speculation exists in the literature that observed differences in tinidazole plasma concentrations between males and females may be due to sex-mediated pharmacokinetic differences. To investigate this phenomenon, a study was designed to determine the pharmacokinetics of tinidazole in male and female subjects. Six male and six female volunteers were each administered a single 2-Gm oral dose of tinidazole. Plasma and urine samples, collected over a 72-hour period, were assayed by a sensitive and specific HPLC assay. Results demonstrate a significant correlation between tinidazole oral plasma clearance and body weight and apparent volume of distribution of tinidazole and body weight for male and female subjects, respectively. There were no apparent sex-mediated differences in weight-normalized pharmacokinetic parameters as documented by statistically equivalent mean oral plasma clearances (36.1 and 35.4 ml/kg/hour), apparent volumes of distribution (0.65 and 0.63 liter/kg), and elimination half-lives (12.3 and 12.3 hours, males and females, respectively). Mean area under the tinidazole plasma concentration-versus-time curve and mean peak plasma concentration of tinidazole were 1.3 times greater for females than for males, apparently due to the smaller mean body weight of females and consequently a 1.3 times greater administered dose to the females on a weight basis.

Adult↗