1. What is paracetamol’s mechanism of action?  How does it differ from that of aspirin?

Paracetamol is a weak COX-1 and COX-2 inhibitor. It contains analgesic and antipyretic effects. Unlike aspirin it has no anti-inflammatory effects, nor does it affect platelet aggregation.

2. Name the indications for paracetamol.  Under which circumstances is it a drug of choice for the treatment of mild pain and fever?

Paracetamol is given for light to moderate pain. It would be the drug of choice for patients who are pregnant, have asthma, gout, suffer from peptic ulcers and haemophiliac patients.

3. Name side-effects that can occur with paracetamol use.  Concentrate only on general side effects and not on acute paracetamol overdose.

General side effects include skin rash, urticaria.

4. Due to the ready availability of paracetamol and the general perception by the public that paracetamol is a very safe drug, paracetamol poisoning (by accident/intentional) is fairly common.  Compile a report in which you discuss acute paracetamol toxicity, stressing the dose, signs and symptoms and treatment.  In your textbook, as well as in the SAMF, there is valuable information that you can use.

Paracetamol toxicity

Paracetamol toxicity occurs when live catalysing conjugation is saturated, that is when toxic NAPQI is formed. The glutathione “pathway” is diminished, causing an excess/ accumulation in NAPQI which then leads to hepatotoxicity.  Unfortunately, paracetamol toxicity is a common suicide method.

Dose

Toxic doses include anywhere between 10-15g of acetaminophen.

Signs and symptoms

This includes nausea, vomiting, abdominal pain, fatigue, weakness, renal impairment, and hepatotoxicity that occurs at a later stage.

Treatment

Treatment for acetaminophen toxicity includes therapy that contains NAC, which helps restore glutathione which conjugates with NAPQI, leading to non-toxic effects. Within 1 hour of the overdose, one can induce vomiting, gastric lavage or use activated charcoal.