Mrs Patell is a 64 year old woman with osteoarthritis of the right knee. A year ago, her general practitioner had recommended up to 4000 mg/day of paracetamol (acetominophen) for pain localised at the medial compartment of the knee. Mrs Patell had been taking the paracetamol but had forgotten that her general practitioner had mentioned that it should not be taken with alcohol. She has recently seen a newspaper article warning people about the risks of chronic use of analgesics. The article warns against liver damage when taking high doses of paracetamol in association with alcohol.

After reading the newspaper article she became worried, because she enjoys a cocktail before dinner and shares a bottle of wine while eating with her husband. She knew she needed to take something; her pain was intolerable with lower doses and the pain also limits her abilities to help her husband with routine tasks around the house.