Preamble. This will also probably replace front page. Might need a separate category on 'clinical presentation/syndromes', 'concepts', and 'antidotes'. Each of these main components are prefixed with 'index_'.

• Basic Concepts
• Cardiovascular
• Pulmonary
• Neurology
• Psychopharmacology
• Renal
• GI/hepatic
• Endocrine
• Hematology
• Oncology
• Infectious diseases
• Substances of abuse
• Metals
• Household products
• Pesticides
• Environmental (e.g. CO)
• Natural toxins