Alkalinization, of urine

Renal dysfunction (high dose regimens) caused by precipitation of drug in renal tubules hydration (3 L/m2/day) and alkalinization of urine... 

Alkalinization of urine Hematuria, renal colic, costovertebral pain, and formation of urate stones associated with use in gouty patients may be prevented by alkalization of urine and liberal fluid intake monitor acid-base balance. 

Crystalluria Nephrotoxicity develops as a result of crystalluria. Adequate hydration and alkalinization of urine prevent the problem by reducing the concentration of drug and promoting its ion-... 

All three studies maintained alkalinity of urine by administering an agent such as sodium bicarbonate in order to minimise differences in urinary excretion. 

Ejellstedt E, Denneberg T, Jeppsson JO, Tiselins HG. A comparison of the effects of potassium citrate and sodium bicarbonate in the alkalinization of urine in homozygous cystinuria. Urol Res 2001 29(5) 295-302. 

Acidification of urine —increases ionization of weak bases —> increases renal elimination. Alkalinization of urine — increases ionization of weak acids —> increases renal elimination. 

Alkalinization of urine — increases ionization of weak acids —> increases renal elimination. 

Dextroamphetamine is a sympathomimetic amine that is used in narcolepsy and in attention-deficit disorder (ADD) in children. Dextroamphetamine releases norepinephrine and, in high doses, also dopamine. It is absorbed from the GI tract, metabolized in the liver, and excreted unchanged in the urine. Acidification of urine shortens amphetamine s half-life, whereas alkalinization of urine prolongs it. The accumulation of hydroxy metabofite of amphetamine has been thought to cause amphetamine-induced psychosis. Therapeutic doses of amphetamine may cause insomnia, tremor, and restlessness, and toxic doses of amphetamine may cause mydriasis, hypertension, and arrhythmia. Chlor-promazine is an excellent antidote in amphetamine toxicity. 

Phenobarbital is absorbed from the small intestine. As much as 50% binds to albumin, and it is metabolized in the liver to hydroxyphenobarbital. Approximately 20 to 25% of phenobarbital is excreted in the urine unchanged. It has a very long elimination half-life of up to 140 hours. Therefore, it is administered orally in a dose of 2 to 3 mg/kg once a day. The renal excretion of phenobarbital is enhanced by the alkalinization of urine, which favors its ionization and excretion. NaHC03 has been used in the management of phenobarbital toxicity. 

PO. Well absorbed, enters CNS, excreted without undergoing metabolism, half-life = 4-6 hrs. Elimination is slowed by alkalination of urine. Often abused. Severe tolerance and dependence. Methamphetamine ( Speed") acts similarly, but is very addictive and often abused. MAO inhibitors hypertensive crisis, CNS overstimulation. Barbiturates supraadditive mood elevation. Tricyclic Antidepressants potentiate CNS stimulation, inhibit metabolism of amphetamine. Overdose treatment Acidify urine. Give chlorpromazine to treat CNS symptoms and alpha-receptor blocker to lower blood pressure. 

ADMINISTERING BICARBONATE The nurse gives oral sodium bicarbonate tablets with a full glass of water the powdered form is dissolved in a full glass of water. If oral sodium bicarbonate is used to alkalinize the urine, the nurse checks the urine pH two or three times a day or as ordered by the primary health care provider. If the urine remains acidic, the nurse notifies the primary health care provider because an increase in the... 

Although generally well tolerated, probenecid can cause gastrointestinal side effects such as nausea and other adverse reactions, including fever, rash, and rarely, hepatic toxicity. Patients should be instructed to maintain an adequate fluid intake and urine output to decrease the risk of uric acid stone formation. Some experts advocate alkalinizing the urine to decrease this risk. 

Vigorous intravenous hydration with dextrose 5% in water with half-normal saline at 3 L/m2 per day to maintain a urine output of 100 mL/m2 per hour or more is necessary, unless the patient presents with acute renal dysfunction. Alkalinization of the urine to a pH of 7.0 or more with 50 to 100 mEq/L of sodium bicarbonate has been used to promote uric acid solubility for excretion. This measure is controversial because xanthine and hypoxanthine are less soluble at alkaline pH, potentially leading to crystallization, especially during and after allopurinol therapy32 (see Fig. 96-6). Medications that increase serum... 

Alkalinization of the urine with sodium bicarbonate is useful in the treatment of poisoning with... 

Introduction of microbiological methods for the determination of amino acids made possible the estimation of the amount of both free and combined amino acids in urine. Dunn et al. (D4), Thompson and Kirby (Tl), Eckhard and Davidson (El), and Woodson et al. (W3) estimated the amount of amino acids liberated in the course of acid or, as in the case of tryptophan determination, alkaline hydrolysis. Microbiological and colorimetric methods used for the determination of certain amino acids present very little opportunity for evaluating the proper quantitative relations between free and combined amino acids, since under the applied condition both combined and free amino acids are equally involved in the reaction. In 1949 Albanese et al. (A3) applied such methods to the quantitative determination of free and combined amino acids in the nondiffusible fraction of urine, and subjected the procedures to broad criticism from just this point of view. 

Since acid-forming amino acids are present primarily in proteins, a number of papers have reported the effect of feeding various levels of protein to human subjects. Sherman and Gettler (23) postulated that food ash determined the acidity or alkalinity of the urine. 

The same considerations hold for acidic molecules, with the important difference that alkalinization of the urine (increased pH) will promote the deprotonization of -COOH groups and thus impede reabsorption. Intentional alteration in urinary pH can be used in intoxications with proton-acceptor substances in order to hasten elimination of the toxin (alkalinization phenobarbi-tal acidification amphetamine). 

Drugs that make the urine alkaline Alterations of urine pH toward the alkaline condition may lead to an accumulation of the drug with a possible increase in adverse effects. 

Crystalluria may develop and can be prevented by the maintenance of urine at a neutral or alkaline pH. 

Both acid and alkaline manipulation of urine applies the principle of ion-trapping in the renal tubules. However, acid diuresis is not advocated because of the risk of developing myoglobinuria and acute renal failure. The intent of modifying the urine pH toward an acidic side is to promote the excretion of drugs with an alkaline pKa such as phencyclidine or amphetamine. 

The adverse effect of formation of urate stones in the kidney can be reduced by adequate hydration and alkalinization of the urine. 

Ammonium chloride increases urinary volume with acidification of urine. The excretion of amphetamine is decreased in relatively alkaline urine and has proved useful in the treatment of amphetamine intoxication. ... 

Alkalinisation of urine (alkaline diuresis) is effective for salicylates and phenoxyacetate herbicides. 

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