Poisoning forced diuresis

Osmotically acting diuretic agents. These are applied in the treatment of intoxication in order to increase the urine volume and accelerate elimination of the poison ( forced diuresis ). The classical example is mannitol. This sugar is quite similar to glucose in structure but does not get metabolized nor reabsorbed from the primary glomerular filtrate in the kidneys. 

A variety of therapies for thallium poisoning have been suggested by neutralising thallium in the intestinal tract, hastening excretion after resorption, or decreasing absorption. Berlin-Blue (fertihexacyanate) and sodium iodide in a 1 wt % solution have been recommended. Forced diuresis hemoperfusion and hemodialysis in combination results in the elimination of up to 40% of the resorbed thaHous sulfate (39). 

Elimination of absorbed substances may be accomplished by administering multiple dose activated charcoal for poisons with entero-hepatic recirculation or by altering urine pH to promote excretion. Forced diuresis, if warranted, should only be done after carefully exercising precautions such as the provision of adequate hydration and maintaining electrolyte balance. 

In the management of refractory edema, the high ceiling diuretics may be used in conjunction with other types of diuretics. They are also useful for forced diuresis in hypnotic or other poisonings. 

Phenobarbitone Sodium Phenobarbitone sodium decomposes in aqueous solutions. Barbiturate poisoning may be treated with stomach wash and administration of activated charcoal. Monitoring respiratory, cardiovascular, and renal functions, hemodialysis, charcoal administration, forced diuresis, symptomatic and supportive therapy, and peritoneal dialysis may be performed. 

If urine flow increases, the time that a drug is exposed to the reabsorptive surface of the kidney is decreased. This principle forms the basis for the treatment of certain extreme cases of acute drug overdose. In these situations patients undergo forced diuresis with large volumes of fluid in order to accelerate drug clearance (e.g., meprobamate poisoning). 

The same strategy - artificial alkalization or acidification of the urine - is quite commonly employed in the clinical treatment of poisonings. However, if the poison (drug) is neither acidic nor basic, the only option is to increase the urine volume. In this case, the amount of the drug (assuming it to be membrane-permeant, as many are) eliminated will simply be proportional to the volume of urine produced. This strategy is called forced diuresis . Another, more effective but also more involved method for the accelerated elimination of hydrophobic drugs such as barbi-... 

When a dmg is in its unionised form it will more readily diffuse from the urine to the blood. In an acidic urine, acidic drugs will diffuse back into the blood from the urine. Acidic compounds such as nitrofurantoin are excreted faster when the urinary pH is alkaline. Amfetamine, imipramine and amitriptyline are excreted more rapidly in acidic urine. The control of urinary pH in studies of pharmacokinetics is thus vital. It is difficult, however, to find compounds to use by the oral route for deliberate adjustment of urinary pH. Sodium bicarbonate and ammonium chloride may be used but are unpalatable. Intravenous administration of acidifying salt solutions presents one approach, especially for the forced diuresis of basic dmgs in cases of poisoning. 

Lassen, N. A. Treatment of severe acute barbiturate poisoning by forced diuresis and alkalinisation of the urine. The LancetII, 338 (1960). 

There are no methods known to accelerate the active transport of poisons into urine, and enhancement of glomerular filtration is not a practical means to facilitate elimination of toxicants. However, passive reabsorption from the tubular lumen can be altered. Diuretics inhibit reabsorption by decreasing the concentration gradient of the drug from the lumen to the tubular cell and by increasing flow through the tubule. Furosemide is used most often, but osmotic diuretics also are employed ("see Chapter 28). Forced diuresis should be used with caution, especially in patients with renal, cardiac, or pulmonary complications. 

Bumetanide is used in the treatment of renal insufficiency and, in conditions which warrant forced diuresis regimens for the control and management of acute drug poisoning e.g., barbiturate poisoning in attempted suicide cases. It is also employed in the treatment of oedema. 

Teshima D et al Usefulness of forced diuresis for acute boric add poisoning in an aduit. J Clin Pharm Thar 2001 26(5) 387-390. [PM ID 11679030] (In this case report, 3.25 L of IV fluid and 100 mg of furosemide were given over 4 hours, and the measured urinary elimination of borale was reported to be equal to that reported with hemodialysis. The authors suggest that this procedure be considered in patients with massive boric acid ingestion.)... 

C. In the past, mannitol had been used to induce forced diuresis for some poisonings (eg, phenobarbital, salicylate) to enhance their renal elimination, but has been abandoned due to lack of efficacy and potential risks (cerebral and pulmonary edema). 

It is controversial as to whether hemoperfusion, hemodialysis, peritoneal dialysis, or forced diuresis is most effective and as to whether any treatment measures are effective in massive thallium poisonings [20,21]. The combination of forced diuresis, hemoperfusion, and hemodialysis can remove up to 40% of absorbed thallium. Aggressive treatment is recommended based on a patient s... 

Gastric aspiration and lavage should be carried out if the patient is seen within 4 hours of overdosage to remove any unabsorbed drug from the stomach. Previously recommended treatments include administration of corticosteroids, antihistamines and heparin, forced diuresis, haemodialysis and charcoal column haemoperfusion (230 ). However, none of these measures prevent liver damage in severely poisoned patients, and some are frankly dangerous. 

Drugs and poisons can in principle be removed from the systemic circulation by forced osmotic diuresis. These are theoretical concepts used in the... 

The effect of varying urinary pH has been used in the treatment of drug overdose by applying forced alkaline diuresis as an adjunct to the treatment of salicylate or phenobarbitone poisoning. The success of the treatment is limited by the extent to which these drugs are distributed, and by the presence of... 

A 21-month-old girl was prescribed erythromycin for an upper respiratory tract infection. At the same time, her parents had been giving her approximately 300 mg of aspirin every 4 hours. The child s condition deteriorated and 2 days later she was admitted to hospital with a temperature of 105°F. She was then prescribed more aspirin, and shortly thereafter had a convulsion for which she was given phenobarbitonc, dexamethasone and tetracycline. Fluid therapy was started, but there was no urine output, and she became progressively obtunded and hyperpnoeic. The patient was transferred to another hospital where the diagnosis to salicylate poisoning was made. She appeared well hydrated, the arterial blood pH was 7.26 and the serum salicylate concentration was 470 Mg/ml. Forced alkaline diuresis was started but had to be restricted because of poor urine output, periorbital oedema and hyponatraemia. The plasma osmolality fell to 264 mOsm/1. Diuresis with recovery eventually followed fluid restriction and administration of mannitol (20 -). 

Tetany is a rare complication of salicylate poisoning, and is probably due to the combination of hypocalcaemia and alkalosis caused by hyperventilation and forced alkaline diuresis. In one recently reported case prolonged tetany was followed by a bilateral... 

The basic treatment of moderate to severe salicylate poisoning is gastric aspiration and lavage followed by forced alkaline diuresis. If there is doubt concerning fluid balance, therapy may be monitored by a central venous catheter (33 -). Acetazol-amide is very effective in raising urine pH but it aggravates acidosis and increases the toxicity and lethality of salicylate in mice (34). It should be avoided. 

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