Urine excretion

Betaxolol hydrochloride is a lipophilic, cardioselective -adrenoceptor blocker having no ISA and Httie membrane-stabilizing activity. The dmg is as equieffective and equipotent as atenolol. It is well absorbed from the GI tract, but does not undergo extensive first-pass metaboHsm in the Hver. Its elimination half-Hfe is 15—20 h. It is metabolized in the Hver ( 84%) to two principal inactive metaboHtes and one minor active metaboHte. About 16% of the dmg is excreted unchanged urine. Excretion of the dmg is unchanged in patients having renal or Hver impairment (43). 

Following inhalation exposure to trichloroethylene in humans, the unmetabolized parent compound is exhaled, whereas its metabolites are primarily eliminated in the urine. Excretion of trichloroethylene in the bile apparently represents a minor pathway of elimination. Balance studies in humans have shown that following single or sequential daily exposures of 50-380 ppm trichloroethylene, 11% and 2% of the dose was eliminated unchanged and as trichloroethanol, respectively, in the lungs 58% was eliminated as urinary metabolites and approximately 30% was unaccounted for (Monster et al. 1976, 1979). Exhaled air contained notable concentrations of trichloroethylene 18 hours after exposure ended because of the relatively long half-life for elimination of trichloroethylene from the adipose tissue (i.e., 3.5-5 hours) compared to other tissues (Fernandez et al. 1977 Monster et al. 1979). 

Calculation of ID using biological monitoring techniques requires the knowledge of the pharmacokinetics of the parent pesticide in laboratory animals. This will allow the use of the parent or its urine metabolite(s) to calculate the total amount of the parent that had been absorbed through the skin of the test subject. The amount of the residue in the urine should be corrected for any molecular weight differences between the parent and its urine metabolite(s) and also corrected for daily urine excretion volumes based on creatinine analysis of the urine samples. 

Information on the excretion of americium after dermal exposure in humans or animals is extremely limited. Some qualitative information is available from an accidental exposure in which a worker received facial wounds from projectile debris and nitric acid during an explosion of a vessel containing 241 Am (McMurray 1983). The subject also inhaled 241Am released to the air as dust and nitric acid aerosols, which was evident from external chest measurements of internal radioactivity thus, excretion estimates reflect combined inhalation, dermal, and wound penetration exposures (Palmer et al. 1983). Measurements of cumulative fecal and urinary excretion of241 Am during the first years after the accident, and periodic measurements made from day 10 to 11 years post accident indicated a fecal urine excretion ratio of approximately 0.2-0.3, although the ratio was approximately 1 on day 3 post accident (Breitenstein and... 

Hammond SE, Lagerquist CR, Mann JR. 1968. Americium and plutonium urine excretion following acute inhalation exposure to high-fired oxides. Am Ind Hyg Assoc J 29(2) 169-172. 

The relationship between exposure and internal dose is known only for a few pyrethroids. Human volunteer studies have shown that, after a single oral administration, pyrethroids and the respective metabolites are excreted in urine within 24 hr and do not accumulate in the body. In field workers exposed to cypermetrin through the dermal route, urine excretion of the intact compound and its metabolites peaked 36 hr after exposure had ceased (WHO, 1989). 

Species Category Fecal excretion contribution (%) Urine excretion (fig day-1) Excreted hormones... 

After a single dose, elimination occurred by way of several routes catabolism to tetrachlorohydroquinone excretion of unchanged PCP and its glucuronide conjugate in urine excretion of PCP or its metabolites into bile. More than 90% was eliminated during the rapid phase, the Tb 1/2 being 13-17 h (Braun etal. 1977)... 

Renal function Measurement of effects on urine excretion in saline loaded rats Renal dynamics Measurement of renal blood flow, GFR and clearance... 

Anuria Diarrhea Polyuria Urogenital Region An absence of or sharp decline in urine excretion. An abnormal frequency and liquidity of fecal discharge. An abnormally sharp increase in the amount of urine excretion. 

White rats given a single dose of radiolabeled disulfoton intraperitoneally eliminated the metabolites phosphoric acid (4.1 %), DEP (61.2%), and DETP (24.8%) in urine as a percentage of excretory metabolites 10-12 hours after exposure (Bull 1965). Approximately 24 and 48 hours after exposure 14.1% and 28.6%, respectively, of the administered dose was excreted in the urine. Excretion rates for disulfoton and its metabolites were not determined. Mice eliminated 30--60% of the radiolabeled intraperitoneal dose of disulfoton in the urine and 2-3% in the feces within 96 hours of exposure (March et al. 1957). 

An interesting study that was performed on dendrimers is also applicable to hyperbranched polymers. Roberts et al. [134] studied the effect of the dendrim-er size when used inside the human body. They found that large dendrimers (M ca. 87,000) were passed into the urine and excreted within two days. Smaller dendrimers (M ca. 5,000), on the other hand, accumulated mostly in the liver, kidney and spleen with no urine excretion. Since most hyperbranched polymers are polydisperse, this might create a problem for in vivo applications. 

Diuretics (saluretics) elicit increased production of urine (diuresis). In the strict sense, the term is applied to drugs with a direct renal action. The predominant action of such agents is to augment urine excretion by inhibiting the reabsorption of NaCl and water. 

Water and water-soluble compounds are excreted with the urine. The volume and composition of urine are subject to wide variation and depend on food intake, body weight, age, sex, and living conditions such as temperature, humidity, physical activity, and health status. As there is a marked circadian rhythm in urine excretion, the amount of urine and its composition are usually given relative to a 24-hour period. 

Metabolism/Excretion-The liver metabolizes 80% to 92% of the drug the remainder is excreted unchanged in the urine. Excretion is mainly renal (90%), with less than 10% appearing in feces. 

Dermatitis. Inflammation of the skin. Diabetes mellitus. A chronic syndrome of impaired carbohydrate, protein, and fat metabolism owing to insufficient secretion of insulin or to target tissue insulin resistance. Diabetes. A general term referring to disorders characterized by excessive urine excretion (polyuria), as in diabetes mellitus and diabetes insipidus. 

Mechanism of Action An antidote that binds with iron to form complex. Therapeutic Effect Promotes urine excretion of acute iron poisoning. 

Pharmacokinetics Rapidly and completely absorbed following oral administration. Protein binding High. Extensively metabolized in liver. Excreted in urine. Excretion is dependent upon urinary pH and is increased in alkaline urine. Half-life 3-8 hr (dose-dependent). 

Aspirin (acetylsalicylic acid, Figure 7.9) is a derivative of salicyclic acid, which was first used in 1875 as an antipyretic and antirheumatic. The usual dose for mild pain is 300-600 mg orally. In the treatment of rheumatic diseases, larger doses, 5-8 g daily, are often required. Aspirin is rapidly hydrolysed in the plasma, liver and eiythrocytes to salicylate, which is responsible for some, but not all, of the analgesic activity. Both aspirin and salicylate are excreted in the urine. Excretion is facilitated by alkalinisation of the urine. Metabolism is normally very rapid, but the liver enzymes responsible for metabolism are easily saturated and after multiple doses the terminal half-life may increase from the normal 2-3 h to 10 h. A soluble salt, lysine acetylsalicylic acid, with similar pharmacological properties to aspirin, has been used by parenteral administration for postoperative pain. Aspirin in low doses (80-160 mg daily) is widely used in patients with cardiovascular disease to reduce the incidence of myocardial infarction and strokes. The prophylaxis against thromboembolic disease by low-dose aspirin is due to inhibition of COX-1-generated thromboxane A2 production. Because platelets do not form new enzymes, and COX-1 is irreversibly inhibited by aspirin, inhibition of platelet function lasts for the lifetime of a platelet (8-10 days). 

Large individual variations in the urine excretion of methadone are observed depending on urine volume and pH, the dose and rate of metabolism. Acidification of the urine may increase the urinary output of methadone from 5 to 22%.37 Typically, following a 5-mg oral dose, methadone and EDDP account for 5% of the dose in the 24-h urine. In those individuals on maintenance therapy, methadone may account for 5 to 50% of the dose in the 24-h urine and EDDP may account for 3 to 25% of the dose. (S)- and (R)-methadone and EDDP have been reported in saliva38 and methadone and (S)- and (R)-methadone in human breast mi Ik.39 40... 

When kidneys fail, no filtration of blood occurs, and urine excretion diminishes. Water accumulates in the interstitial fluid, hence the swelling. 

However, the question as to whether the first methylation step, the conversion from noradrenaline to adrenaline, is an active process over-all in the body should be susceptible of fairly easy study by repeating the experiments of Richter and Macintosh (12) and of Beyer and Shapiro (4) but administering noradrenaline instead of adrenaline. The urine-excreted compounds could be bioassayed after suitable hydrolysis and the relative amounts of noradrenaline and adrenaline in the hydrolyzate determined by using the differential activities of the two compounds on rabbit intestine and rat uterus as first reported by West (16). The differences between normal persons and those in successive stages of essential hypertension with regard to their abilities to conjugate noradrenaline and adrenaline and with regard to their abilities to transform the former into the latter surely should be a subject of precise chemical study in the near future. 

Exposure assessment using alpha cellulose pads and DEP urine excretion were made on 8 workers applying ethion on a daily basis in two citrus groves in Orange County, Florida. The study format was divided into three phases ... 

When a specimen is collected at one specific time of day, one person may be excreting at his maximum concentration and another person at his minimum concentration. For example, one day a person excreted 6300 ml of urine while one of his colleagues employed in a similar duty excreted 606 ml. Assuming both had absorbed the same amount of pesticide, we would expect similar amounts to be excreted. If only a partial urine sample was collected and analyzed, a tenfold error would be made due to dilution. Consequently, all of the urine excreted daily must be collected and the volume recorded before an aliquot is taken for analysis. 

Klatt et al. (1975) described a method of collecting urine excreted by large animals. On the basis of urine funnels used in rats, an appropriate larger metabolism cage made out of transparent, rigid polyvinyl chloride was used. The cage was improved by a built-in sieve cone which assured good separation of urine and feces. A device to measure and record the time and amount of voided urine was attached. Urine was collected in a vessel with a hose connection from the bottom to... 

Urine excretion is calculated in ml/kg. Uric acid-, creatinine- and ion-excretions are calculated in mmol/kg and expressed as percent changes versus controls. The changes are evaluated statistically using Student s t-test. 

In case that an essential part of dose is excreted via urine, an estimation of absorption is often done giving the ratio of urine excretion (oral/intravenous) as absorption rate. It should be compared with the ratio of the dose-normalized plasma AUCs (oral/intravenous). 

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