Reasons for administering amlodipine included the following: four cases in which gastrointestinal symptoms developed following the administration of an ACE inhibitor (ACEI), two cases in which using an ACEI would worsen a condition, such as during ongoing treatment for Addison’s disease or hyperadrenocorticism, nine cases in which ACEI administration did not result in blood pressure changes; six cases in which renal function markers increased after ACEI administration and 24 cases of mitral regurgitation where a strong left atrial pressure-reducing effect of amlodipine was expected. This evidence concerns the gene ACE and Mitral regurgitation.