Description
Mechanism of Action
Paracetamol exhibits analgesic action by peripheral blockage of pain impulse generation. It produces antipyresis by inhibiting the hypothalamic heat-regulating centre. Its weak anti-inflammatory activity is related to inhibition of prostaglandin synthesis in the CNS.
Onset: Oral: <1 hr. IV: 5-10 min (analgesia); w/in 30 min (antipyretic).
Duration: 4-6 hr (analgesia). IV: ≥6 hr (antipyretic).
Absorption: Readily absorbed from the GI tract. Time to peak plasma concentration: Approx 10-60 min (oral).
Distribution: Distributed into most body tissues; crosses the placenta and enters breast milk. Plasma protein binding: Approx 25%.
Metabolism: Hepatic via glucuronic and sulfuric acid conjugation. N-acetyl-p-benzoquinoneimine (minor hydroxylated metabolite), is usually produced in very small amounts by CYP2E1 and CYP3A4 isoenzymes in the liver and kidneys.
Excretion: Mainly via urine (as glucuronide and sulfate conjugates, <5% as unchanged drug). Elimination half-life: Approx 1-3 hr.
MIMS Class
Analgesics (Non-Opioid) & Antipyretics
ATC Classification
N02BE01 – paracetamol; Belongs to the class of anilide preparations. Used to relieve pain and fever.;
