Dr Ahmed Darwish
02-05-2009, 01:12 AM
بسم الله الرحمن الرحيم
اقدم لزملائي الصيادله والاطباء مجموعه مهمه في علم ال Toxicology حيث جمعت ال drugs علي هيئة
Sources
Mechanism of Action
Symptoms
Antidote/Treatment
Notes
بالاضافه الي المراجع Reference
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Toxicon: Acetaminophen (Tylenol ® and others)
Source: NSAID
Mechanism of Action: Acetaminophen is rapidly absorbed from the stomach and small intestine and metabolized by conjugation in the liver to nontoxic agents, which then are eliminated in the urine. In acute overdose or when maximum daily dose is exceeded over a prolonged period, the normal pathways of metabolism become saturated. Excess acetaminophen is then metabolized in the liver via the mixed function oxidase P450 system to a toxic metabolite. Under conditions of excessive metabolite formation or reduced glutathione stores, the reactive metabolite is free to covalently bind to vital proteins and the lipid bilayer of hepatocytes; this results in hepatocellular death and subsequent centrilobular liver necrosis.
Symptoms: 0-24 hr: asymptomatic, pallor, anorexia, nausea & vomiting, malaise; 18-72 hr: right upper quadrant abdominal pain & rising liver enzymes (AST & ALT), tachycardia, hypotension; after 3-4 days: hepatic dysfunction with jaundice, recurrence of nausea & vomiting, renal failure, possible death; otherwise after 4day - 3 week: resolution of symptoms.
Antidote/Treatment: The antidote for acetaminophen poisoning is N-acetylcysteine (Mucomyst ®). It increases glutathione stores, combines directly with acetaminophen's reactive metabolite as a glutathione substitute, and enhances sulfate conjugation. It also functions as an anti-inflammatory and antioxidant.
Oral activated charcoal avidly adsorbs acetaminophen & should be given within 1-2 hours after ingestion of acetaminophen, or if the time of ingestion is unknown. Supportive therapy, including IV fluids, oxygen, and cardiac monitor
Notes: Acetaminophen is the most widely used pharmaceutical analgesic and antipyretic agent in the United States and the world. It is contained in more than 100 products. As such, acetaminophen is one of the most common pharmaceuticals associated with both intentional and accidental poisoning.The toxic dose of APAP after a single acute ingestion is 150 mg/kg or approximately 7 g in adults, although the at-risk dose may be lower in persons with alcoholism and other susceptible individuals. When dosing recommendations are followed, the risk of hepatotoxicity is extremely small.
اقدم لزملائي الصيادله والاطباء مجموعه مهمه في علم ال Toxicology حيث جمعت ال drugs علي هيئة
Sources
Mechanism of Action
Symptoms
Antidote/Treatment
Notes
بالاضافه الي المراجع Reference
----------------------------------------------------------------------------------------------
Toxicon: Acetaminophen (Tylenol ® and others)
Source: NSAID
Mechanism of Action: Acetaminophen is rapidly absorbed from the stomach and small intestine and metabolized by conjugation in the liver to nontoxic agents, which then are eliminated in the urine. In acute overdose or when maximum daily dose is exceeded over a prolonged period, the normal pathways of metabolism become saturated. Excess acetaminophen is then metabolized in the liver via the mixed function oxidase P450 system to a toxic metabolite. Under conditions of excessive metabolite formation or reduced glutathione stores, the reactive metabolite is free to covalently bind to vital proteins and the lipid bilayer of hepatocytes; this results in hepatocellular death and subsequent centrilobular liver necrosis.
Symptoms: 0-24 hr: asymptomatic, pallor, anorexia, nausea & vomiting, malaise; 18-72 hr: right upper quadrant abdominal pain & rising liver enzymes (AST & ALT), tachycardia, hypotension; after 3-4 days: hepatic dysfunction with jaundice, recurrence of nausea & vomiting, renal failure, possible death; otherwise after 4day - 3 week: resolution of symptoms.
Antidote/Treatment: The antidote for acetaminophen poisoning is N-acetylcysteine (Mucomyst ®). It increases glutathione stores, combines directly with acetaminophen's reactive metabolite as a glutathione substitute, and enhances sulfate conjugation. It also functions as an anti-inflammatory and antioxidant.
Oral activated charcoal avidly adsorbs acetaminophen & should be given within 1-2 hours after ingestion of acetaminophen, or if the time of ingestion is unknown. Supportive therapy, including IV fluids, oxygen, and cardiac monitor
Notes: Acetaminophen is the most widely used pharmaceutical analgesic and antipyretic agent in the United States and the world. It is contained in more than 100 products. As such, acetaminophen is one of the most common pharmaceuticals associated with both intentional and accidental poisoning.The toxic dose of APAP after a single acute ingestion is 150 mg/kg or approximately 7 g in adults, although the at-risk dose may be lower in persons with alcoholism and other susceptible individuals. When dosing recommendations are followed, the risk of hepatotoxicity is extremely small.