NEW: Drug Toxicity 3

What happens in Phase I (24 hours) of an acetaminophen overdose?

- GI upset

- Metabolic acidosis at doses > 75 g

What happens in Phase II (1-3 days) of an acetaminophen overdose?

- Hepatotoxicity

- Increased liver enzymes

- Death becomes a possibility

What happens in Phase III (3-5 days) of an acetaminophen overdose?

Irreversible liver damage

What happens in Phase IV (5-14 days) of an acetaminophen overdose?

- Recovery

- Liver is permanently damaged

What are the toxic doses of acetaminophen?

- 125-200 mg/kg

- 10 g for an adult

- 5 g for a child

What is the mechanism of toxicity for acetaminophen?

- Glutathione depletion

- Metabolite covalently binds to proteins

- Cell death occurs

What are the key points of N-acetylcysteine?

- Treats acetaminophen overdose

- Use if patient took > 200 mg/kg

- Best within 8 hours, benefit within 24 hours

- 72-hour oral regimen

- 24-hour IV regimen

How does alcohol impact acetaminophen toxicity?

- Chronic ingestion enhances metabolism

- Acute ingestion prevents metabolism

How should an acetaminophen overdose be treated?

- < 30 minutes, use activated charcoal with sorbitol

- Use overdose nomogram

- If patient falls above the solid line, treat with NAC

- Time-consuming, may require multiple blood draws

- Line moves down and to the left if there is an underlying liver condition

What happens in a mild salicylate overdose?

- Nausea/vomiting

- GI bleeding

- Tinnitus

What happens in a moderate salicylate overdose?

- Confusion

- Hyperventilation

What happens in a severe salicylate overdose?

- Hallucinations

- Seizures

- Coma/death

What happens in Phase I (12 hours) of a salicylate overdose?

- Respiratory alkalosis

- Impaired consciousness

- Hyperventilation

What happens in Phase II (12-24 hours) of a salicylate overdose?

- Metabolic acidosis

- Bleeding

What happens in Phase III (> 24 hours) of a salicylate overdose?

Full-blown acidosis

What are the toxic doses of salicylates (aspirin)?

- 200 mg/kg (15 g)

- 300 mg/kg (20 g) is fatal

How should a salicylate overdose be treated?

- Activated charcoal

- IV sodium bicarbonate

What are the uses of opioids?

- Analgesia

- Sedation

- Antitussive

- Antidiarrheal

What are the signs/symptoms of an opioid overdose?

- CNS and respiratory depression

- Miosis (pinpoint pupils)

- Decreased bowel sounds

- Slightly decreased blood pressure

What is the treatment for oral opioid toxicity?

- Maintain breathing

- Activated charcoal

What are the key points of naloxone?

- Short-acting

- Treats parenteral opioid overdose

- Precipitates withdrawal