Paracetamol is indicated in:
- Fever,common cold and influenza.
- Headache,toothache, earache, bodyache, myalgia, dysmenorrhoea, neuralgia and sprains.
- Pain of colic, back pain, post-operative pain, postpartum pain, chronic pain of cancer, inflammatory pain, and post-vaccination pain and fever of children.
- Rheumatism and osteoarthritic pain & stiffness of joints in fingers, hips, knees, wrists, elbows, feet, ankles and top & bottom of the spine.
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.
Paracetamol (Acetaminophen) is thought to act primarily in the CNS, increasing the pain threshold by inhibiting both isoforms of cyclooxygenase, COX-1, COX-2, and COX-3 enzymes involved in prostaglandin (PG) synthesis. Unlike NSAIDs, acetaminophen does not inhibit cyclooxygenase in peripheral tissues and, thus, has no peripheral anti-inflammatory affects. While aspirin acts as an irreversible inhibitor of COX and directly blocks the enzyme’s active site, studies have found that acetaminophen indirectly blocks COX, and that this blockade is ineffective in the presence of peroxides. This might explain why acetaminophen is effective in the central nervous system and in endothelial cells but not in platelets and immune cells which have high levels of peroxides. Studies also report data suggesting that acetaminophen selectively blocks a variant of the COX enzyme that is different from the known variants COX-1 and COX-2. This enzyme is now referred to as COX-3. Its exact mechanism of action is still poorly understood, but future research may provide further insight into how it works. The antipyretic properties of acetaminophen are likely due to direct effects on the heat-regulating centres of the hypothalamus resulting in peripheral vasodilation, sweating and hence heat dissipation.
Dosage & Administration
- Adult: 1-2 tablets every 4 to 6 hours up to a maximum of 4 gm (8 tablets) daily.
- Children (6-12 years): ½ to 1 tablet 3 to 4 times daily. For long term treatment it is wise not to exceed the dose beyond 2.6 gm/day.
Extended Release Tablet:
- Adults & Children over 12 years: Two tablets, swallowed whole, every 6 to 8 hours (maximum of 6 tablets in any 24 hours).The tablet must not be crushed.
- Children under 3 months: 10 mg/kg body weight (reduce to 5 mg/kg if jaundiced) 3 to 4 times daily.
- 3 months to below 1 year: ½ to 1 teaspoonful 3 to 4 times daily.
- 1-5 years: 1 -2 teaspoonful 3 to 4 times daily.
- 6-12 years: 2-A teaspoonful 3 to 4 times daily.
- Adults: 4-8 teaspoonful 3 to 4 times daily.
- Children 3-12 months: 60-120 mg,4 times daily.
- Children 1-5 years: 125-250 mg 4 times daily.
- Children 6-12 years: 250-500 mg 4 times daily.
- Adults & children over 12 years: 0.5-1 gm 4 times daily.
- Children Upto 3 months: 0.5 ml (40 mg)
- 4 to 11 months: 1.0 ml (80 mg)
- 7 to 2 years: 1.5 ml (120 mg). Do not exceed more than 5 dose daily for a maximum of 5 days.