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 469 records · Page 26Linked to original sources
PubMed1985

Fecal skatole and indole and breath methane and hydrogen in patients with large bowel polyps or cancer.

The object of this study was to explore the use of fecal skatole and indole and breath methane and hydrogen as metabolic markers of the anaerobic colonic flora in patients with unresected large bowel cancer or polyps. Patients with descending or sigmoid colon cancer were more likely to be breath methane excretors than control subjects, patients with proximal colon cancer, and patients with rectal cancer. Control subjects excreting breath methane excreted less fecal skatole than breath methane excretors in the following groups: patients with adenomatous polyps, all patients with colorectal cancer, patients with proximal colon cancer, patients with descending and sigmoid colon cancer, and patients with rectal cancer. These data suggest that fecal skatole excretion equal to or greater than 100 micrograms/g feces might be useful to discriminate colorectal cancer patients from control subjects. Twenty-nine percent (8 of 28) of the cancer patients had both "high" skatole levels and breath methane excretion compared with only 2% (1 of 41) of the control subjects (P less than 0.01).

Bacteria↗
PubMed1998

A 3-month, double-blind, controlled trial of feeding with sucrose polyester in human volunteers.

Sucrose polyester (SPE) is a tasteless, odourless substance which reduces plasma cholesterol concentrations and may therefore be valuable as a fat substitute in human foodstuffs. It has recently been approved for use in snack foods by the United States Federal Drug Administration. The current study was designed to investigate its effects on gastrointestinal physiology and nutrient absorption in human subjects. A 6-month (2 x 3-month periods) double-blind, placebo-controlled, randomized, cross-over trial of SPE and control fat was performed in healthy free-living volunteers. Subjects consumed 20-40 g of SPE daily (mean 26.8 (SE 6.8) g) which reduced the intake of total and saturated fat but had no effect on energy intake or body weight. Plasma cholesterol and triacylglycerols were reduced. The frequency of bowel movements and their urgency were increased and anal leakage occurred in 7.2% of subjects. Abdominal pain was more frequent in subjects receiving SPE and was significantly greater than in the control group after 8 weeks feeding. The plasma concentrations of vitamin E and six carotenoids were significantly reduced. Routine haematology and biochemistry, other vitamins, intestinal biopsies, bile-salt retention, rectal prostaglandins, fractional Ca absorption and aminopyrine metabolism were unaffected. The ingestion of foods containing 20-40 g SPE daily provoked significant gastrointestinal problems. This intake is greater than that to be expected from the use of SPE in savoury snack foods, for which it has been approved by the United States Federal Drug Administration. However, the favourable effects on lipid profiles must be balanced against the reduction in the concentrations of vitamins and carotenoids, as these compounds may have beneficial effects on health through protection from free-radical oxidative stress.

Adult↗
PubMed1984

Absorption and bioavailability of calcium and magnesium salts of indomethacin from rectal suppositories.

In order to estimate the application to rectum of calcium and magnesium salts of indomethacin (IND), the suppositories of the salts and IND were prepared using macrogol and Witepsol H-15 bases. The rectal administration of these suppositories (Witepsol H-15) was compared with the oral administration of IND and the salts. The hardness, melting point, and liquefaction time of the suppositories were similar between IND and the salts. The in vitro release of IND-Mg from the suppositories was significantly faster than that of IND, while the release of IND-Ca was slower. The area under the plasma drug concentration-time curve (AUC) after IND suppositories was significantly higher than that after oral administration of IND (p less than 0.01). The AUC value after IND-Ca suppositories was slightly higher than those after other suppositories, although the plasma levels in early period after IND-Ca suppositories were lower, indicating the slow absorption of IND-Ca. The multiple treatment with IND-Ca suppositories gave no histological change of the rectal mucosa. Therefore, the present results suggested that IND-Ca was favourable for the rectal administration, in high doses and repeatedly.

Administration, Oral↗
PubMed1979

First-pass effect after rectal administration of thiazinamium methylsulfate.

The absorption and metabolism of the quaternary ammonium compound thiazinamium methylsulfate were studied in humans using plasma concentration data and urinary excretion measurements. After giving a dose of 150 mg in suppositories, the relative bioavailability was 5.8 +/- 3.2 (SD) % of the dose, comparable to the values obtained following oral administration. The degree of first-pass effect observed after rectal administration was comparable with that after oral administration.

Aged↗
PubMed2003

Pharmacokinetics of intravenous and rectal ketoprofen in young children.

OBJECTIVE: To evaluate the relative bioavailabilities of ketoprofen after intravenous and rectal administration to young children. DESIGN: Open-label prospective parallel-group study. PATIENTS: Participants were 28 children aged 7 to 93 months. METHODS: Eighteen children received a single intravenous injection of ketoprofen 1 mg/kg, and ten children, weight 16-24 kg, received a 25mg ketoprofen suppository. Venous blood samples were collected at selected times after administration, ranging from 2 minutes to 8 hours for the intravenous group and from 30 minutes to 8 hours for the suppository group. A validated high performance liquid chromatography method was used to measure plasma ketoprofen concentrations. RESULTS: In the intravenous group, the maximum plasma concentration of ketoprofen ranged between 10.5 and 22.2 mg/L, and in the suppository group, following dose normalisation to 1 mg/kg of ketoprofen, between 3.8 and 7.4 mg/L. In the intravenous group, area under the concentration-time curve from zero to infinity ranged between 9.2 and 23.5 mg x h/L, and in the suppository group after dose normalisation between 8.8 and 12.9 mg x h/L. The bioavailability of ketoprofen from the suppository was about 73%. Volume of distribution was 0.04-0.10 L/kg in the intravenous group and 0.08-0.16 L/kg in the suppository group. The terminal half-life was comparable in both study groups, ranging between 0.7 and 3.0 hours in the intravenous group and between 1.2 and 2.9 hours in the suppository group. CONCLUSION: Absorption of ketoprofen after rectal administration is reasonably rapid and predictable. Because the bioavailability of rectal ketoprofen is also relatively high, a suppository may be used in children in whom the drug cannot be given intravenously or by mouth.

Administration, Rectal↗
PubMed1996

Absorption of glycine irrigating solution during endoscopic transanal resection of rectal tumors.

PURPOSE: This study was undertaken to evaluate the potential metabolic complications of 1.5 percent glycine irrigating solution during endoscopic transanal resection (ETAR) of rectal tumors. METHODS: Thirteen consecutive frail patients (mean age, 81 (range, 57-91) years) undergoing 18 ETAR were prospectively studied from July 1993 to January 1995. Indications for ETAR included palliation of advanced rectal cancer (12 patients) and an extensive villous tumor (1 patient). A 27-French two-way Iglesias resectoscope was used. Packed cell volume, blood glucose, and serum concentrations of sodium, potassium, and creatinine were measured before, during (at 45 minutes), and after (at 6 and 24 hours) ETAR. Plasma concentration of glycine and hemoglobin levels were both measured preoperatively and at 45 minutes and 24 hours, respectively. Variables studied included resection time, volume and rate of irrigating fluid, height of irrigating fluid bag above operating table, resectate weight, occurrence of intraperitoneal and extraperitoneal perforation, blood loss, and clinical symptoms. RESULTS: Two patients were excluded. Mean operating time was 456 minutes. A mean of 192.3 liters of irrigant was infused into the rectum. Mean irrigation rate was 43,330 ml/minutes. Mean height of irrigating fluid bag was 692 cm. Extraperitoneal perforation occurred in two patients. Blood loss exceeded 200 ml in four patients, one of whom complained of nausea (operating time, 110 minutes). Mean rise in p-glycine at 45 minutes (10,028 mol/l; 387 percent of preoperative values) was significant (P = 0.006). Changes in packed cell volume, b-hemoglobin, b-glucose, s-sodium, and s-creatinine levels were not significant. There was significant correlation between p-glycine and s-creatinine levels at six hours (P = 0.033), between p-glycine levels and fall in s-sodium at 24 hours (P = 0.037), and between levels of b-hemoglobin and packed cell volume at 24 hours (P = 0.0004). There was a positive linear correlation between p-glycine and operating time (r = 0.7; P = 0.0026) and between p-glycine and volume of irrigating fluid (r = 0.5; P = 0.0386). CONCLUSIONS: Operating time best predicts increase of p-glycine in ETAR.

Adsorption↗
PubMed1988

The effects of carbidopa dose and time and route of administration on systemic L-dopa levels in rats.

The effects of carbidopa dose and time and route of administration on systemic plasma levels of parenterally and nonparenterally administered L-dopa were examined in rats. Intravenous coadministration of L-dopa + carbidopa resulted in significant (P less than 0.05) carbidopa-dependent increases in both the area under the plasma L-dopa concentration versus time profile (AUC; +27%) and the plasma L-dopa half-life (t1/2; +35%). Simultaneous duodenal or rectal carbidopa administration did not alter the L-dopa i.v. pharmacokinetic profile. Carbidopa pretreatment significantly increased the i.v. L-dopa AUC (+38 and +82% for i.v. and duodenal pretreatments, respectively) compared to simultaneous administration. Both i.v. and duodenal carbidopa increased duodenal L-dopa AUC to a similar extent (+282 and +239% for i.v. and duodenal administration, respectively). Rectal studies indicated poor absorption of both L-dopa and carbidopa, with no demonstrable effect on plasma L-dopa. The results indicate that the timing and route of carbidopa and L-dopa administration are important in determining the extent of i.v. or duodenal L-dopa systemic availability. The rat model affords results similar to those reported in human studies and may be useful for more extensive evaluation of L-dopa and carbidopa interactions.

Animals↗
PubMed1997

Kinetics of absorption and elimination of ofloxacin in humans after oral and rectal administrations.

Ofloxacin pharmacokinetics have been studied in four healthy subjects after a single oral or rectal dose, each of 200 mg. For the oral dose tmax was about 2 h, Cmax 1.96 +/- 0.56 micrograms/ml and AUC1-15 15.22 micrograms/ml.h. Two-phase elimination pharmacol kinetics were observed for the oral dose, t1/2 for the rapid elimination phase was 3.3 h and for the slow phase 10 h. With the rectal dose tmax was 6 h, Cmax 0.71 +/- 0.44 microgram/ml and AUC0-15 7.58 micrograms/ml.h. The relative rectal bioavailability (AUC rectal/AUC oral) was 49.8%. Elimination rate of the rectal dose was generally slow (t1/2 = 9 h), an observation attributable to the sustained-release effect of the rectal suppository base, PEG 6000. The indication is that the rectal formulation cannot be substituted totally for the oral without first increasing the rectal dose; the 200 mg suppository can however be employed as a follow-up therapy to the oral dose in certain situations.

Administration, Oral↗
PubMed1989

Safety and efficacy of acetarsol suppositories in unresponsive proctitis.

In a prospective open study, 10 patients with intractable proctitis were treated with acetarsol suppositories (250 mg b.d. for 4 weeks) and were monitored clinically, biochemically and toxicologically. Proctitis resolved symptomatically and sigmoidoscopically within 2 weeks in nine patients; one patient was unaffected. The only side-effect was of transient thrombocytosis in a single patient. Maximal blood and urinary arsenic concentrations occurred after 1 week's treatment with a total inorganic arsenic in the hazardous range in six patients; subsequent concentrations fell despite continuing therapy and at 4 weeks potentially hazardous values persisted in only two patients. Continued renal excretion and diminished absorption across an improved rectal mucosa is thought to be responsible for this paradox. Arsenic levels fell rapidly when acetarsol was withdrawn and were indistinguishable from pretreatment values within 4 weeks. Short-term acetarsol therapy offers a useful additional measure when local steroids have failed to control ulcerative proctitis; it appears to be safe and formal controlled comparisons with other therapeutic options are therefore legitimate.

Adult↗
PubMed1983

Low bioavailability of ergotamine tartrate after oral and rectal administration in migraine sufferers.

Fifteen migraine patients were administered 2 mg ergotamine tartrate in a partial cross-over design as a single, oral tablet, rectal suppository and rectal solution. Eight of these patients were in a previous investigation given 0.5 mg ergotamine tartrate intravenously. The blood samples were taken up to 54 h after oral and suppository while it was followed for only 3 h after rectal solution. The chemical analysis was performed by applying h.p.l.c. method with a limit of sensitivity of 0.1 ng/ml ergotamine base in plasma. No ergotamine was detected in the blood samples after the oral route, whereas small and very variable quantities was found in blood after the rectal route. Regular calculation of bioavailability could therefore not be performed. An estimate of the maximal possible bioavailability was found to yield a mean value of 2% (tablets); 5% (suppositories) and 6% (rectal solution). Rectal solution elicited faster absorption and the extent of absorption was significantly higher (P less than 0.05) than for the suppository.

Absorption↗
PubMed2000

Mono- and biphasic plasma concentration-time curves of mesalazine from a 500 mg suppository in healthy male volunteers controlled by the time of defecation before dosing.

This study was based on data from a bioequivalence study (n=24) of two different formulations of suppositories containing 500 mg mesalazine (formulation I and II), with a similar dissolution profile in phosphate buffer pH 6.8. There was a large intra- and intersubject variability in the plasma concentration-time curves of mesalazine from both suppositories. The aim of the investigation was to identify the parameters that caused the observed large variations in release and absorption of mesalazine in the rectum. Plasma mesalazine and acetylmesalazine, and urine acetylmesalazine concentrations were determined according to validated methods involving HPLC analysis with coulometric detection. Lower limit of quantitation values were respectively 10.4 and 19.4 ng mL(-1) in plasma and 0.96 microg mL(-1) in urine. The time of defecation before and after insertion was recorded. There was a clear distinction between subjects who showed monophasic mesalazine release/absorption and those who showed biphasic and more extended release/absorption. With formulation I there was a correlation between time of defecation before dosing and the type of absorption, monophasic and biphasic absorbers showed a significant difference in the time of defecation, e.g. 9.7+/-5.6 h vs 18.8+/-11.9 h (P = 0.0218). The impact of time of defecation before dosing was non-significant with formulation II, 16.7+/-7.2 h vs 15.1+/-4.2 h (P = 0.67). The impact of the time elapsed between administration and time of defecation after the insertion of the suppository was not significant for the type of release/absorption. The plasma concentration-time curves of the metabolite ran parallel to that of the parent drug, the more parent drug was released/absorbed, the more was acetylated (P = 0.0013) and excreted into the urine (P = 0.0004). After absorption the compound was metabolized into acetylmesalazine, and renally excreted (12-13% of the dose). Monophasic release/ absorption resulted in 7.1% metabolite with I and 10.3% with II (P = 0.0004), while biphasic release/absorption gave 16.8% metabolite with I and 15.5% with II. The renal clearance of the metabolite acetylmesalazine was independent of the observed defecation patterns (300 mL min(-1), P > 0.8), stool composition, and type of absorption.

Absorption↗
PubMed2001

Increased vigabatrin entry into the brain by polysorbate 80 and sodium caprate.

The effects of a non-ionic surfactant, polysorbate 80, and the sodium salt of the saturated fatty acid, sodium caprate (C10), as potential brain absorption enhancers for vigabatrin were studied. Vigabatrin is an enzyme-activated irreversible inhibitor of gamma-aminobutyric acid (GABA) transaminase that increases brain and cerebrospinal GABA concentrations in animals and man. Before intravenous administration, a range of concentrations of the surfactants were tested using erythrocyte lysis or the red blood cell lysis test to establish the non-toxic concentration range. Vigabatrin was dissolved in 0.1% polysorbate 80 and 0.1% sodium caprate and administered intravenously in doses of 4 mL kg(-1) to male Wistar rats (230-250 g; n = 3). Rats were killed 2 h after drug and surfactant administration and the brains were immediately removed and homogenized in 0.4 M perchloric acid. Selected ion monitoring electrospray mass spectrometry was used to determine the concentration of vigabatrin and GABA directly from the perchloric acid extract of the rat brain. This method was developed to increase the speed and efficiency of the analysis by removing the need for complex extraction and derivatization procedures while retaining the specificity of the mass spectrometer as a detector. The stability of both vigabatrin and GABA in perchloric acid was established by monitoring their pseudo molecular ions in standard solutions at timed intervals over 24 h. Although the detection level for vigabatrin and GABA was at least 50 pg, only GABA was detected in rat brain. Vigabatrin caused a small increase in whole brain GABA. However, GABA levels were higher in the samples with vigabatrin + enhancer than in the samples where vigabatrin alone was administered. One-way analysis of variance indicated a significant effect of the surfactants on GABA levels (F (5,17) = 11.86, P < 0.01) and vigabatrin absorption was presumed. The rectal temperature of the rats is lowered by the presence of vigabatrin in the brain. Vigabatrin alone decreased rectal temperature by 6%. When given with either polysorbate 80 or sodium caprate, the extent of temperature lowering was significantly greater (P < 0.001). There was no significant difference after 2 h between polysorbate 80 + vigabatrin, and sodium caprate + vigabatrin.

Animals↗
PubMed1999

Role of methadone in the management of pain in cancer patients.

In most cancer patients who are treated with opioid analgesics for pain control, the type of opioid needs to be changed at least once because of the presence of side effects or the need to escalate analgesic doses to toxic levels. Methadone may be an excellent alternative in such patients due to its lack of known active metabolites, high lipid solubility, excellent absorption following oral and rectal delivery, and extremely low cost. However, it has unique problems, such as a long, unpredictable half-life and greater potency than previously assumed. At present, methadone is viewed as a second-line opioid for chronic cancer pain. Better pharmacokinetic and clinical studies are required to establish the role of methadone in this setting. Issues to be explored include a potential role in treating patients who have poorly responsive pain syndromes, such as neuropathic pain, or who develop a rapid tolerance to other opioids; the possibility of extending dosing intervals to every 12 or 24 hours; and its possible use as a first-line opioid.

Analgesics, Opioid↗
PubMedDate not supplied

[The aging gastrointestinal tract--diseases of the gastrointestinal tract in old age].

Gastrointestinal symptoms in geriatric patients are not necessarily due to disorders of the gut or even consequence of aging. The high capacity in regard to motoric phenomena, secretion and absorption prevents deficiency syndromes. The spectrum of geriatric gastrointestinal diseases does not differ from the one seen in the normal population except of the increasing rate of malignancies. Multimorbidity and consecutive polypragmasy may be responsible for iatrogenic disorders of the gastrointestinal tract.

Aged↗