Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rectal Absorption”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1982

Single-dose kinetics and bioavailability of ketobemidone.

The single-dose kinetics and the oral and rectal bioavailability of ketobemidone have been studied in patients after surgery. Plasma concentrations were determined following intravenous administration of Ketogin 2 ml, containing ketobemidone chloride 10 mg and the spasmolytic substance N, N-dimethyl-3, 3-diphenyl-l-methylallylamine chloride 50 mg and following oral or rectal administration of Ketogin. Ketobemidone was analyzed by gas chromatography-mass spectrometry using a deuterated internal standard. Ketobemidone disappeared rapidly from plasma after i.v. or oral administration, yielding a mean plasma half-life between 2.25 and 2.45 h. After rectal administration the plasma half-life was somewhat prolonged (3.27 h), probably due to late absorption., The bioavailability of oral ketobemidone was 34% +/- 16% s.d. (n = 6), and when given rectally 44% +/- 9% s.d. (n = 5). In contrast to earlier investigations performed without plasma analysis, ketobemidone was found to have a rapid elimination when given intravenously, orally or rectally.

Administration, Oral↗
PubMed1993

Bioavailability and diuretic effect of bumetanide following rectal administration of suppositories containing weak acids in human subjects.

The bioavailability of bumetanide following the oral administration of tablets, or the rectal administration of either macrogol suppositories or suppositories with and without weak acids were evaluated in human subjects. The absorption of bumetanide from those suppositories containing bumetanide without weak acids (control suppositories) was extremely poor, while the absorption from those suppositories containing citric acid or tartaric acid was enhanced. The mean area under the plasma concentration-time curve (AUC) following the rectal administration of the suppositories containing citric acid and tartaric acid was 52 and 62%, respectively, of that following the oral administration. On the other hand, the absorption rate constant (ka) and the mean residence time (MRT) following the rectal administration of the suppositories containing weak acids increased significantly compared to those administered orally. The time (Tmax) required to achieve the maximum plasma concentration (Cmax) in the plasma following the rectal administration of the suppositories containing weak acids was significantly shortened compared to the time of those administered orally. These results indicated that the bumetanide contained in the suppositories containing weak acids might be absorbed rapidly after administration. The diuretic effect of bumetanide following the oral and rectal administration was also evaluated. Sufficient diuretic effects were obtained following the rectal administration of the suppositories containing weak acids.

Administration, Oral↗
PubMedDate not supplied

Relative bioavailability of rectally administered phenobarbital sodium parenteral solution.

Rectal administration of antiepileptic drugs may be a useful alternative route when oral administration is not possible due to illness, surgery, or status epilepticus. Although parenteral administration often replaces oral administration in these circumstances, there is not always a desirable intravenous line available or repeated intramuscular injections may not be practical. The purpose of this study was to determine the relative bioavailability and time course of absorption of the commercially available parenteral phenobarbital sodium solution administered rectally in comparison with the same preparation given intramuscularly. Seven healthy adult volunteers were given phenobarbital 5 mg/kg intramuscularly and rectally five weeks apart. Eighteen blood samples were drawn over 288 hours. Pharmacokinetic parameters following intramuscular versus rectal administration were the following: area under the curve 5916 vs. 5253 mumol.h/L; half-life 112 vs. 113 h; time to maximum concentration 2.1 vs. 4.4 h; and maximum serum concentration 36.2 vs. 31.4 mumol/L. Mean relative bioavailability for rectal phenobarbital was 90 percent. Therefore, the parenteral phenobarbital sodium solution given rectally is well absorbed and provides a useful alternative route of administration.

Administration, Rectal↗
PubMed2003

Case report: Rectal adminstration of ivermectin to a patient with Strongyloides hyperinfection syndrome.

Strongyloides hyperinfection syndrome may be complicated by paralytic ileus that interferes with the absorption of oral anti-helminthics. We report on the administration of ivermectin as a rectal enema preparation to a renal transplant recipient with Strongyloides hyperinfection syndrome and progressive ileus. Attempts at treatment using nasogastric albendazole and ivermectin were unsuccessful despite clamping the nasogastric tube after drug administration. Ivermectin tablets were ground to a powder, resuspended in a commercially available suspending agent, and administered per rectum. The suspending agent was chosen for its near-physiologic osmolality to allow longer retention, in contrast to many enema preparations that have a laxative effect. The patient improved markedly within 72 hours of initiation of the therapy per rectum and recovered fully. Ivermectin administered as an enema may be beneficial in patients with severe strongyloidiasis who are unable to absorb or tolerate oral therapy.

Administration, Rectal↗
PubMed1987

Clinical and manometric assessment of anorectal function after Martin's operation.

Anorectal function after Martin's operation for total colonic aganglionosis was assessed in five patients by clinical and manometric studies. One year after operation the frequency of bowel movements decreased to three times a day, and the stools became semi-formed. Anorectal manometry showed decreasing anal resting pressure and anorectal pressure difference one month after the operation. However, these values became gradually normal. Rectal compliance increased as bowel function improved clinically. These results show that increasing rectal compliance and normalisation of stools by adequate absorption of intestinal fluid are important factors in the improvement of faecal continence after Martin's operation.

Child, Preschool↗
PubMed1986

A comparison of the effects of hyperosmotic salicylate solutions in closed and perfused rectal in-situ loops of rats.

The effects of presentation of hyperosmotic solutions of sodium salicylate to the closed and perfused rectal loop preparations commonly used in assessing drug absorption have been compared. Epithelial cell loss was quantified in control and treated loops. Tissue damage was significantly greater (P less than 0.01) in treated perfused loops. Fluid efflux, which was associated with a small but significant change in the haematocrit value, was noted in both systems.

Animals↗
PubMed1989

Physiological effects of feeding high levels of magnesium to sheep.

The effects of feeding high levels of Mg to sheep on animal health, nutrient digestibility, metabolism of macro-minerals, blood and tissue mineral concentrations and hematological and histological tissue changes were evaluated. Six lambs were allotted to each of four diets supplemented with MgO to attain .2, .6, 1.2 or 2.4% Mg. Total fecal and urinary collections were made for the initial 20 d and last 10 d of a 50 d study. Diarrhea was noted in lambs fed the two highest Mg levels. Apparent digestibility of DM, ADF and CP decreased linearly (P less than .01) with increasing Mg levels. Dietary Mg levels did not affect (P greater than .05) rectal temperature, respiration rate or pulse rate. Apparent absorption and retention of Mg (g/d) were lowest in lambs fed 2.4% Mg until 15 d on trial, after which values increased linearly (P less than .01) with dietary Mg. Phosphorus absorption and retention decreased linearly (P less than .01) with increasing Mg levels. Increasing dietary Mg resulted in a linear increase (P less than .01) in serum Mg and variable increases (P less than .05) in erythrocyte Mg. Serum Ca was decreased linearly (P less than .05) and quadratically (P less than .05) by added Mg during the d 1 to 30 and 40 to 50 periods, respectively. Serum inorganic P was elevated consistently in lambs fed 2.4% Mg. A linear response to increasing dietary Mg (P less than .05) occurred in the Mg content of liver, kidney, rib bone and femur bone. Dietary Mg did not alter (P greater than .05) other criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1976

Metronidazole retention enema in the management of severe intestinal amoebiasis.

Metronidazole is a drug of proven efficacy in amoebiasis; however its use is restricted in patients who cannot take the drug by mouth, because of severe complications of the disease. Preliminary studies in eight control subjects show that rapid absorption and high serum levels are achieved after rectal administration of 2 gm. of metronidazole in 200 ml. of normal saline. Six patients with severe intestinal amoebiasis treated with metronidazole retention enema are presented, and they illustrate the efficacy of the new method of therapy. The efficacy of metronidazole in anaerobic bacteriodes infection and its proven amoebicidal effcet also indicate the possible use of the metronidazole retention enema technique in bowel preparation for colonic surgery in developing countries.

Administration, Rectal↗
PubMed1985

Dietary fibre: consensus and controversy.

Technological advances have reduced and refined man's plant food intake and consequently brought about an unprecedented decline in his consumption of dietary fibre (DF). The emergence of certain diseases selectively in regions which have been affected the most by this dietary change has led to an enhanced awareness of the functions of DF. DF is a heterogeneous group of substances which resist digestion by the endogenous enzymes of the human gut, although they are fermented to a substantial extent by the bacterial flora of the large intestine. Chemically, DF essentially consists of nonstarch polysaccharides and lignin, and its major constituents are cellulose, hemicelluose, lignin and pectin. The physiological effects of DF are attributable largely to its physicochemical properties. DF primarily affects gastrointestinal (GI) function; its effects are observable at all stages from ingestion through defaecation. It restricts caloric intake, shows gastric and small intestinal transit, and affects the activity of digestive enzymes and release of GI hormones. Its overall impact is to reduce apparent digestibility of nutrients marginally but consistently. In the large intestine, DF accelerates transit, supports bacterial growth and serves to hold water. As a result, the faecal weight and water content increase, and the transit time generally becomes shorter. Secondary to its GI effects, DF attenuates postprandial glycaemia and has long term effects on glucose tolerance and lipoprotein metabolism. These effects have important implications in the aetiopathogenesis of constipation and its sequelae including diverticulosis, cholesterol gallstones, colorectal cancer, obesity, diabetes mellitus and atherosclerosis. DF has traditionally been used therapeutically for constipation; now its use in diabetes is also well established. Our appreciation of the role of DF in human nutrition has undergone a major change in the last two decades. From a redundant constituent of plant foods, it has now moved to the position of an essential nutrient, the deficiency of which seems to have serious consequences.

Animals↗
PubMed1988

Polarity and differentiation of human rectal adenocarcinoma cells in suspension and collagen gel cultures.

HRA-19a1.1. cells, derived from a primary human rectal adenocarcinoma, form polarized monolayers when grown on tissue-culture plastic. The apical membrane of the cells is in contact with the culture medium while the basolateral surface is attached to the plastic substratum. Cells cultured on non-tissue-culture plastic form floating colonies. Cells within these colonies are orientated so that their apical membrane is in contact with the culture medium while the basolateral membrane faces the centre of the colony. When these colonies are embedded in collagen gel the cells organize to form glandular structures similar to those observed in xenografts of this cell line. In addition a reversal in the orientation of cell polarity is observed with the basolateral membrane now in contact with the collagen gel, while the apical membrane faces lumina within the colony. This interaction is specific to collagen gel, as in a control experiment where colonies are embedded in agarose gel, neither a reversal in polarity nor the formation of glandular structures is observed. These results demonstrate an induction of glandular organization in human rectal adenocarcinoma cells by collagen gel. In addition an increased absorptive cell differentiation and reversal in cell polarity is observed in response to collagen gel.

Adenocarcinoma↗
PubMed1991

Rectal bioavailability of water-soluble drugs: sodium valproate.

The influence of adjuvants in suppository formulations on the release and absorption of sodium valproate, a water soluble anti-epileptic, was analysed in order to determine the optimal formula for rectal administration. Three formulations were prepared with Suppocire AS2(formula I), Aerosil R 972 (formula II) or Span 80 (formula III). In-vivo and in-vitro release-diffusion studies were performed using white laboratory rabbits as the experimental model. The adjuvants decreased the percentage release of valproic acid to 96.7% (formula I) and 84.1% (formula II), and delayed peak release-diffusion concentration (210 and 150 min, respectively, with formulas II and III in comparison with 120 min with formula I). Their effect on bioavailability was observed as an increase in plasma levels of the active substance, with areas under the plasma concentration/time curve of 396.26 and 306.64 micrograms h mL-1 (formulas II and III, respectively) and 243.28 micrograms h mL-1 (formula I). The time to peak plasma concentration was also delayed with peaks at 30, 55 and 50 min with formulas I, II and III, respectively.

Adjuvants, Pharmaceutic↗
PubMedDate not supplied

Pathways of paracetamol absorption from layered excipient suppositories: artificial intelligence approach.

When studying paracetamol availability after rectal administration, the differences between slower and faster release suppositories were discovered. Approach with modelling and simulation of compartment-based models was used to explore the differences. A study of paracetamol from layered excipient suppositories shows that many different mechanisms are involved in the drug pharmacokinetics. There is also a large number of articles, each dealing with only one or with a few of the mechanisms. However, there is little information available on how the mechanisms interact in the organism and thus govern the pharmacokinetics of the drug, which means that systemic view in the expert knowledge is missing. In the case of paracetamol rectal availability the use of partially fuzzyfied model allowed systemic combination of all described mechanisms found in the literature and measured data. In spite of non-identifiability, the model showed that patterns that explained differences in bioavailabilities of the two formulations of suppositories could be found. Results of modelling and simulation show that "in vivo" there is practically no difference in cumulative release profiles between the two formulations. However, due to higher content of mono-di-glycerides in a slower release formulation, the extent of absorption is augmented both by absorption-enhancing effect of mono-di-glycerides and the liver bypass mechanism via diminished viscosity.

Acetaminophen↗
PubMed2002

Clinical pharmacokinetics of morphine.

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.

Administration, Oral↗
PubMed1988

Enzymatic barriers to peptide and protein absorption.

Continuing advances in biotechnology promise to provide a large number of peptides and proteins that would significantly expand the range of pharmaceuticals to treat diseases now poorly controlled. Even at this early stage, it is clear that the success of these entities as drugs of the future would depend, at least in part, on the success in overcoming the obstacles in their delivery. Chief among these are the ubiquitous enzymatic barriers. These include the site of administration, where the peptide is placed, the vascular endothelium that peptides must cross to enter the circulation, the blood that distributes the peptide to its target site, and the liver and kidneys where the peptide is metabolized and eliminated, respectively. The review examines: (1) the nature and efficiency of the enzymatic barriers in degrading peptides and proteins at various absorption sites, and (2) the strategies that can be used to perturb these barriers. These sites include the subcutaneous and intramuscular spaces and the intestinal, nasal, buccal, rectal, vaginal, and ocular surfaces.

Absorption↗
PubMed2003

Improvement in the bioavailability of poorly absorbed glycyrrhizin via various non-vascular administration routes in rats.

The purpose of this study was to examine the improvement of the bioavailability of glycyrrhizin (GL) via extra-vascular, i.e. oral, rectal, and nasal routes with or without the aid of an absorption enhancer in place of the vascular intravenous route in rats. Pharmacokinetic behavior following administration via vascular routes, i.e. the intravenous and portal-venous routes was examined in rats. The area under the plasma concentration-time curve (AUC) after administration of GL via the portal vein was decreased slightly, suggesting that the first elimination of GL in the liver may be one of the factors contributing to the low bioavailability after administration via the oral route. When GL was administered orally as a solution (30 mg/kg), the plasma concentration of GL was extremely low. However, after rectal or nasal administration of GL solution (30 mg/kg) with or without sodium caprate, the mean AUC value was remarkably increased compared with oral administration. In particular, the absolute bioavailability of GL after nasal administration was estimated to be approximately 20%, which was approximately 80-fold greater compared with after oral administration despite of the absence of an enhancer. Furthermore, the fatty acids co-administered orally with GL produced an increase in GL absorption in the following order: sodium caprate>sodiumlaurate>sodiumcaprylate>sodium oleate. These results indicate that the rectum and nasal cavity are useful administration routes for systemic delivery of GL. It was also found that the fatty acids were enhancers for the absorption of GL.

Absorption↗
PubMed1986

Prodrugs of 5-fluorouracil. V. 1-Alkoxycarbonyl derivatives as potential prodrug forms for improved rectal or oral delivery of 5-fluorouracil.

The hydrolysis and physicochemical properties of seven 1-alkoxycarbonyl derivatives of 5-fluorouracil were studied to assess their potential as prodrugs with the aim of enhancing the delivery characteristics of the parent drug. All derivatives were hydrolyzed to quantitatively yield 5-fluorouracil. The pH-rate profiles for the hydrolysis were measured. The rates of hydrolysis were markedly accelerated in the presence of plasma, affording half-lives of hydrolysis less than 4 min in 80% human plasma. The derivatives were more lipophilic than 5-fluorouracil but the aqueous solubility was only slightly reduced or, for one derivative, even greater than that of 5-fluorouracil. A preliminary absorption study in rabbits showed an absolute bioavailability of 5-fluorouracil of 100% following rectal administration of 1-(butoxycarbonyl)-5-fluorouracil as compared with no absorption following administration of 5-fluorouracil itself. The potential utility of the prodrug derivatives to enhance the oral and/or rectal delivery of the parent drug is suggested.

Animals↗
PubMed2004

Mucosal drug delivery: membranes, methodologies, and applications.

In recent years, extensive research into novel forms of drug delivery has suggested that mucosal approaches offer a promising therapeutic alternative, especially for systemically acting drugs. Transmucosal drug delivery offers many benefits, including noninvasive administration, convenience, rapid onset, as well as elimination of hepatic first-pass metabolism. The investigated absorptive surfaces consist of the nasal, buccal, ocular, vaginal, and rectal mucosae. Among these, the nasal and buccal routes have proved the most promising to date. The bioavailability achieved mainly depends upon the pathophysiological state of the mucosa and the properties of both the drug and delivery systems. Various agents can increase the efficacy of transmucosal drug delivery. These include cyclodextrins, bile salts, surfactants, fusidic acid derivatives, microspheres, liposomes, and bioadhesive agents. The mechanisms of action, effectiveness, and toxicity profiles of these enhancers have been investigated extensively in both animal and human models.

Absorption↗