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Case Study 3: Alan, 40 , has bipolar disorder, which is controlied on lithium (slow-release preparation, 450mgbd ). He presents to the surgery feeling tired, weak, shaky and complaining of nausea. Your first thought is that he has flu and has been overdoing things. The plasma lithium concentration result is available the next morning and is 1.6mmol/L (therapeutic range for chronic maintenance 0.6 1. 2mmol/L ). The comment on the report draws your attention to the time of the last dose and of sample collection, stating it to be about eight hours post dose. The previous lithium concentration 12 months earlier was 0.8mmol/L. You wonder about the possible explanations for an increase of Alan's lithium concentration into the toxic range. What medical causes might result in this change? A review of his medications shows no obvious candidates for a drug interaction. Further questioning reveals that to lose weight, Alan has taken up jogging every morning, with predictable aches and pains in muscles and joints. In response, he has been taking ibuprofen bought from the local supermarket. Is the ibuprofen significant in this case? Why? (5 pts)