Acetylsalicylic acid

Absorption	Absorption is generally rapid and complete following oral administration but may vary according to specific salicylate used, dosage form, and other factors such as tablet dissolution rate and gastric or intraluminal pH.
Volume of distribution	Not Available
Protein binding	High (99.5%) to albumin. Decreases as plasma salicylate concentration increases, with reduced plasma albumin concentration or renal dysfunction, and during pregnancy.
Metabolism	Acetylsalicylic acid is rapidly hydrolyzed primarily in the liver to salicylic acid, which is conjugated with glycine (forming salicyluric acid) and glucuronic acid and excreted largely in the urine.
Route of elimination	Not Available
Half life	The plasma half-life is approximately 15 minutes; that for salicylate lengthens as the dose increases: doses of 300 to 650 mg have a half-life of 3.1 to 3.2 hours; with doses of 1 gram, the half-life is increased to 5 hours and with 2 grams it is increased to about 9 hours.
Clearance	Not Available
Toxicity	Oral, mouse: LD50 = 250 mg/kg; Oral, rabbit: LD50 = 1010 mg/kg; Oral, rat: LD50 = 200 mg/kg. Effects of overdose include: tinnitus, abdominal pain, hypokalemia, hypoglycemia, pyrexia, hyperventilation, dysrhythmia, hypotension, hallucination, renal failure, confusion, seizure, coma, and death.
Affected organisms	Humans and other mammals
Pathways	Pathway Name Acetylsalicylic Acid Pathway