My advice would be to tell him that whenever he’s taken aspirin it must be ‘quack medicine’ too – aspirin is made from willow bark – an herb. Just as digitalis (an effective heart medication) is derived from foxglove – another herb. I could go on, but you get the point.

My only other comment is that his sciatica must not be too bad if he’s not willing to try something which has a possibility of helping and has a money-back guarantee. I certainly wouldn’t give him much sympathy the next time he complains of the pain!