Metabolism overdose

This patient had ingested a large quantity of aspirin resulting in the classic findings of a salicylate overdose a centrally mediated respiratory alkalosis with a concurrent anion gap metabolic acidosis. 

In toxicity studies, acute toxicity tests are usually carried out in the rat, mouse, cat, and dog. Subacute toxicity studies for IM products are performed by giving SC injections to rats and IM injections to dogs. In IV studies the rat tail vein or a front leg is used. Deliberate overdosing usually washes out metabolism differences between species. In dogs it is common to give an IV dose five times that intended for humans. In rats this is increased to 10 times. 

Adverse reactions to drugs differ in both type and incidence in the pediatric population. Because of immature metabolic pathways, infants and children may have different metabolic patterns than adults. This at least partially explains why neonates require lower theophylline serum concentrations for the treatment of neonatal apnea and why the incidence of hepatotoxi-city following acetaminophen overdose is much lower in young children than in adults [44,45]. Antibiotic adverse effects unique to the pediatric population may... 

Salicylate or aspirin overdose is characterized by tinnitus, confusion, rapid pulse rate, and increased respiration. The decreased partial pressure of arterial C02 (Pco2) plus increased fixed acids first cause alkalosis, which is followed by metabolic acidosis, dehydration, and loss of fixed bases. The picture may resemble diabetic acidosis, but the history of salicylate ingestion and blood salicylate levels above. 540 mg/100 mL clinch the diagnosis. 

Sodium bicarbonate administration for cardiac arrest is controversial because there are few clinical data supporting its use, and it may have some detrimental effects. Sodium bicarbonate can be used in special circumstances (i.e., underlying metabolic acidosis, hyperkalemia, salicylate overdose, or tricyclic antidepressant overdose). The dosage should be guided by laboratory analysis if possible. 

When treating insomnia without depression, doxepin and amitriptyline (both tricyclic antidepressants) can be administered in low doses (25-100 mg) at bedtime. These antidepressants, however, do have troublesome anticholinergic side effects (dry mouth, constipation, blurred vision, dizziness) and adverse effects on the heart, and they can be lethal if taken in overdose. Because of their effect on heart function, these antidepressants should be avoided in patients with heart problems and administered cautiously, if at all, to those who are already receiving one of any number of newer antidepressants that inhibit the metabolism of the TCAs. 

Hemodialysis may be used after an overdose and when the patient is having complications (eg, severe metabolic acidosis, electrolyte imbalances, renal failure). 

The absorption of vitamins K2, which are found mainly in cheese, curd cheese, and natto, is much higher and may be almost complete. Thus the nutritional importance of menaquinones is often underestimated. The vitamin K activity is related to the activation of specific proteins involved in blood clotting and bone metabolism. Clinical vitamin deficiency due to dietary inadequacy is rare or nonexistent in healthy adults, thanks to the widespread distribution of the vitamin K in foodstuffs and the microbiological flora of the gut, which synthesizes menaquinones. Only infants up to 6 months are at risk of bleeding due to a vitamin K deficiency. No data on negative effects of an overdose of vitamin K are found [417]. 

Administration of hyperbaric oxygen following exposure to carbon tetrachloride improved survival from 31 to 96% in rats (Ellenhorn and Barceloux 1988). Hyperbaric oxygen has also been used in treating overdoses of carbon tetrachloride in humans and may correct regional tissue hypoxia and damage, as well as inhibit the P-450-dependent reductive dehalogentation of carbon tetrachloride to the metabolically active acute trichloromethyl radical in the liver. However, the effectiveness of this method has not been established in humans (Burkhart et al. 1991 Ellenhorn and Barceloux 1988). 

Because of its fast onset (minutes), naloxone (Narcan) administered IV is used most frequently for the reversal of opioid overdose. However, it fails to block some side effects of the opioids that are mediated by the ct-receptor, such as hallucinations. The rapid offset of naloxone makes it necessary to administer the drug repeatedly until the opioid agonist has cleared the system to prevent relapse into overdose. The half-life of naloxone in plasma is 1 hour. It is rapidly metabolized via... 

Treatment for severe ethanol overdose is generally supportive. Increased intracranial pressure can be relieved by intravenous administration of hypertonic mannitol. Hemodialysis can accelerate the removal of ethanol from the body. Stimulants of ethanol metabolism, such as fructose, are not sufficiently effective, and use of analeptics is not recommended because of the possibility of precipitating convulsions. 

Mechanism of Action An intratracheal respiratory inhalant that splits the linkage of mucoproteins, reducingtheviscosityof pulmonary secretions.Tiierapeutic Effect Facilitates the removal of pulmonary secretions by coughing, postural drainage, mechanical means. Protects against acetaminophen overdose-induced hepatotoxicity. Pharmacokinetics Protein binding 83% (injection). Rapidly and extensively metabolized in liver. Deacetylated by the liver to cysteine and subsequently metabolized. Excreted in urine. Half-life 5.6 hr (injection). 

Prolonged use or overdose may result in electrolyte or metabolic disturbances (such as hypokalemia, hypocalcemia, and metabolic acidosis or alkalosis), as well as persistent diarrhea, vomiting, muscle weakness, malabsorption, and weight loss. 

Overdose produces metabolic acidosis and tolerance to therapeutic effect, Patient/Family Education... 

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