Within the organ system classes, adverse reactions are listed under headings of frequency (number of patients expected to experience the reaction), using the following categories: very common (> 1/ 10); common (> 1/ 100 ,< 1/10); uncommon (> 1/1000 ,< 1/100); rare (> 1/10,000, < 1/ 1000); very rare (< 1/10 ,000); not known (could not be accurately estimated through clinical studies).