Aspirin and paracetamol are highly effective analgesics which are commonly prescribed in general practice or bought over the counter (OTC). Their safety is well established when they are used appropriately, according to manufacturers' instructions. However, toxic effects can occur, especially with paracetamol taken in overdose.

Community nurse prescribers should be aware of these risks and ensure that they know whether patients are taking OTC preparations containing aspirin or paracetamol. This bulletin considers the issues around the prescribing of these analgesics for adults and children under the care of nurse prescribers.

How do they work?

Both aspirin and paracetamol have analgesic and antipyretic properties. Aspirin is a non-steroidal anti-inflammatory drug (NSAID) which also inhibits platelet aggregation. It works by inhibiting the enzyme cyclo-oxygenase which is involved in the production of prostaglandins and other mediators of inflammation and pain.¹

Summary

• Aspirin and paracetamol are effective analgesics frequently prescribed or purchased over the counter (OTC). While they are most commonly used to treat mild to moderate pain, they can also be used in some forms of severe chronic pain or to relieve breakthrough pain where the patient is taking stronger analgesics.

• Although their safety is well established when used correctly, side effects can occur. Overdosage with paracetamol is particularly dangerous. As there are many combination products containing aspirin or paracetamol available to buy OTC, nurses must be aware of all medicines the patient is taking to avoid accidental overdose.

• Aspirin should not be prescribed for children under the age of twelve years due to its association with Reye's syndrome. It should be prescribed with caution for the elderly as they are more likely to suffer a serious or fatal gastro-intestinal bleed, or be taking drugs that may interact with aspirin.

• Paracetamol is the drug of choice for infants following vaccination. It is a safer alternative to aspirin for elderly patients, but must be used with caution in the malnourished and alcohol abusers as paracetamol metabolism may be impaired in these patients.

• Pyrexia is an important diagnostic sign and can have beneficial effects for the patient. Antipyretic therapy should only be prescribed following assessment, with consideration given to the relative risks and benefits of the treatment.

While the mode of action of paracetamol is unclear, it is thought that its effects are also

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