Minerva: October 2001

The challenge to clinicians caring for men with carcinoma of the prostate is to separate out those with low risk cancers who can simply be watched from those with high risk tumours who need early aggressive treatment. One useful measure (Mayo Clinic Proceedings 2001;76:571-2; 576-81) is the doubling time for the concentration of prostate specific antigen. It seems especially helpful in men whose disease has recurred: a long doubling time is associated with local recurrence whereas a short doubling time suggests systemic recurrence.

Soft drinks are often full of sugar, but cola drinks carry an additional health risk. A report in the Internal Medicine Journal (2001; 31:317-8) describes a patient with chronic caffeine toxicity manifesting as hypokalaemic myopathy. The patient presented with a year's history of muscle weakness, nausea, vomiting, diarrhoea. and weight loss. She admitted drinking 8 litres of cola every day for the past two years, amounting to at least 1 g of caffeine daily. Toxicity can occur at levels as low as …