Paracetamol, Analgesic or Antipyretic?

Paracetamol, also known as acetaminophen or APAP, is a medication used to treat pain and fever. It is typically used for mild to moderate pain.There is poor evidence for fever relief in children It is often sold in combination with other ingredients such as in many cold medications. In combination with opioid pain medication, paracetamol is used for more severe pain such as cancer pain and after surgery. It is typically used either by mouth or rectally but is also available intravenously. Effects last between two and four hours.

Paracetamol is generally safe at recommended doses.Serious skin rashes may rarely occur, and too high a dose can result in liver failure. It appears to be safe during pregnancy and when breastfeeding. In those with liver disease, it may still be used, but lower doses should be taken. Paracetamol is classified as a mild analgesic. It does not have significant anti-inflammatory activity and how it works is not entirely clear.

Medical uses

Fever

Paracetamol is used for reducing fever in people of all ages The World Health Organization (WHO) recommends that paracetamol be used to treat fever in children only if their temperature is greater than 38.5 °C (101.3 °F). The efficacy of paracetamol by itself in children with fevers has been questioned and a meta-analysis showed that it is less effective than ibuprofen

Pain

Paracetamol is used for the relief of mild to moderate pain. The use of the intravenous form for pain of sudden onset in people in the emergency department is supported by limited evidence.

Osteoarthritis

The American College of Rheumatology recommends paracetamol as one of several treatment options for people with arthritis pain of the hip, hand, or knee that does not improve with exercise and weight loss.A 2015 review, however, found it provided only a small benefit in osteoarthritis.

Paracetamol has relatively little anti-inflammatory activity, unlike other common analgesics such as the NSAIDs aspirin and ibuprofen, but ibuprofen and paracetamol have similar effects in the treatment of headache. Paracetamol can relieve pain in mild arthritis, but has no effect on the underlying inflammation, redness, and swelling of the joint. It has analgesic properties comparable to those of aspirin, while its anti-inflammatory effects are weaker. It is better tolerated than aspirin due to concerns about bleeding with aspirin.

Low back pain

Based on a systematic review, paracetamol is recommended by the American College of Physicians and the American Pain Society as a first-line treatment for low back pain. However, other systematic reviews concluded that evidence for its efficacy is lacking

Headaches

A joint statement of the German, Austrian, and Swiss headache societies and the German Society of Neurology recommends the use of paracetamol in combination with caffeine as one of several first line therapies for treatment of tension or migraine headach. In the treatment of acute migraine, it is superior to placebo, with 39% of people experiencing pain relief at 1 hour compared to 20% in the control group.

Uses
Symptomatic relief of mild to moderate pain.

Dosage and administration
Adults: 0.5-1 g repeated, as necessary, every 4-6 hours to a maximum of 4 g daily.
Children: 20-30 mg/kg daily in divided doses.
Dosage should be reduced in patients with renal failure.
Suppositories are available for patients unable to take the drug orally.
Treatment should not be continued for more than 5 days except on medical advice.

Contraindications

• Hypersensitivity to paracetamol.
• Repeated administration is contraindicated in patients with hepatic insufficiency.

Adverse effects
At doses within the therapeutic range paracetamol is usually well tolerated.
Hypersensitivity, dermatological reactions, neutropenia and thrombocytopenic purpura have rarely been reported.

Overdosage

In overdosage paracetamol is dangerously hepatotoxic; potentially fatal hepatic necrosis can occur after ingestion of as little as a single dose of 10-15 g. Signs of mild gastrointestinal irritation are commonly followed 2 days later by anorexia, nausea, malaise, abdominal pain, progressive evidence of liver failure and, ultimately, hepatic coma.

Gastric lavage should be performed or emesis induced whenever there is a possibility that paracetamol remains in the stomach. When feasible, plasma paracetamol concentrations should be determined to assess the risk of liver failure. This is likely when the plasma concentration is greater than 200 micrograms/ml at 4 hours after ingestion, 100 micrograms/ml at 8 hours, 50 micrograms/ml at 12 hours, 25 micrograms/ml at 16 hours and 6 micrograms/ml at 24 hours.

Either methionine or acetylcysteine may be used as a specific antidote. To be effective the antidote must be administered within 16 hours and before signs of hepatic damage become evident. A loading dose of 140 mg/kg administered orally or through a nasogastric tube is supplemented by 70 mg/kg every 4 hours until the results of liver function tests have returned to normal. If this has not occurred within 3 days, no further improvement can be expected.

Fluid and electrolyte balance must be maintained and ventilation must be assisted when respiration is depressed.

Storage
Paracetamol tablets and syrup should be stored in tightly closed containers protected from light, below 25°C. Suppositories should be stored below 15°C.

^REFERENCE
 "International Listings for Paracetamol". Retrieved 11 January 2016.

 ^{https://en.wikipedia.org/wiki/Paracetamol}