Hastening Elimination of the Absorbed Poison

HASTENING ELIMINATION OF THE ABSORBED POISON

  • Elimination can also be hastened by the use of cathartics and laxatives. Contraindicated in dehydration.
  • Osmotic cathartics like sodium sulphate, magnesium sulphate or sorbitol can be given orally.
  • Forced diuresis is an effective method of increasing renal elimination of many compounds. It is indicated in cases of serious clinical toxicosis, ingestion of a potentially lethal dose, and if normal paths of elimination are impaired.
  • Forced diuresis can cause pulmonary edema, cerebral edema, metabolic acidosis or alkalosis, and electrolyte imbalances. Therefore, forced diuresis should only be used when a significant benefit is expected.
  • Osmotic diuretics, loop diuretics and water as diuretic are useful.
  • Many drugs are weak acids or weak bases. If they can be kept in an ionized state, their resorption can be decreased.
  • By altering the urinary pH, it is possible to increase elimination by increasing the proportion of ionized compound.
  • Alkalinizing the urine (increasing pH) increases excretion of acidic compounds such as aspirin while acidifying the urine (decreasing pH) increases excretion of basic compounds like amphetamine and other alkaloids.
  • Acidifiers like ammonium chloride, ascorbic acid and sodium acid phosphate can be used.
  • Alkalisers like sodium bicarbonate, sodium acetate, sodium citrate and Ringers lactate can be used. Hower, the acid-base balance should be monitered closely when pH altering agents are administered.
  • Ammonium chloride given orally will acidify the urine.
  • Urine acidification is contraindicated in liver or kidney failure and myoglobinuria.
  • Plasma potassium and urinary pH should be carefully monitored during urinary acidification.
  • Sodium bicarbonate is used to alkalinize the urine. This is effective in treating barbiturate, salicylate, ethylene glycol and 2,4-D poisonings.
  • Care should be taken to avoid producing metabolic alkalosis.
  • Dialysis can be used to remove toxicants that are not highly protein bound.
  • It is an option in animals with renal failure and when very large amounts of toxicant have been absorbed.
  • Peritoneal dialysis is indicated in small animals.
Last modified: Tuesday, 6 December 2011, 8:05 AM