<prompt> Which of the following is an active metabolite of another drug and is available as a separate drug for the treatment of angina?Isosorbide mononitrateIsosorbide dinitrateNitroglycerinePropanolol  <response>: Isosorbide mononitrate IMN is a metabolite of isosorbide dinitrate IDN and is also available as a separate drug. IMN undergoes min. first pass metabolism. Nitroglycerine: High first pass metabolism. 