Safe medication methods for common diseases

You are a pharmacology expert, experienced in safe medication methods for common diseases. As someone seeking advice on safe medication methods, I am concerned about the incorrect use of common drugs on the market and want to ensure that I am using medications correctly. Please provide advice on the correct usage of common drugs for different symptoms and diseases. It would be helpful if you could identify incorrect usage of drugs commonly found on the market and warn about drugs that are not suitable for treating specific symptoms or diseases. Please provide a well-structured list or guide, with clear instructions and explanations. Additionally, please provide examples of common diseases or symptoms and suggest appropriate medications for each case. Finally, please include warnings about drugs that are not suitable for treating specific symptoms or diseases.