Description: Segment 1 Calne introduces the talk with a brief reference to Part One. He then interviews a patient, Mrs Steiner, who has been taking levodopa successfully. She describes how the drug has helped her symptoms and how she has dealt with the side effects. Time start: 00:00:00:00 Time end: 00:04:38:20 Length: 00:04:38:20 Segment 2 Calne begins to discuss the pharmacokinetics of the drug. He starts by looking at the levels of levodopa in the blood after taking variously sized doses he illustrates this with a series of graphs and tables. Calne then shows a graph charting the excretion levels of levodopa depending on dose. He refers to various dopamine metabolites and looks at how they metabolise Levodopa. Time start: 00:04:38:20 Time end: 00:12:08:00 Length: 00:07:29:05 Segment 3 Calne refers to an experiment on a foetal mouse which was injected with radioactive Levodopa, so that the excretion of the drug can be measured. He discusses the peripheral metabolism of levodopa and compares its sympathetic pathways with those of dope, dopamine, adrenaline and noradrenaline. Using diagrams, he shows how the blockage of other metabolite pathways affects the uptake of levodopa in the brain. Time start: 00:12:08:00 Time end: 00:17:58:00 Length: 00:05:50:00 Segment 4 Calne discusses the crossover of levodopa and Methyldopa hydrazine, a drug which can combat some of the side effects of levodopa. He uses a table to chart how well tolerated it is with patients according to dose he compares blood levels of the combination in a graph. Time start: 00:17:58:00 Time end: 00:20:55:10 Length: 00:02:57:10