Според честотите на нежеланите реакции те са класифицирани като много чести (> 1/ 10), чести (> 1/ 100, < 1/ 10), нечести (> 1/ 1000, < 1/ 100), редки (> 1/ 10000, < 1/ 1000) и много редки (< 1/ 10000).
The frequencies of adverse reactions are classified as very common (> 1/ 10), common (> 1/ 100 ,< 1/10), uncommon (> 1/ 1,000 ,< 1/100), rare (> 1/ 10,000, < 1/ 1,000), and very rare (< 1/ 10,000).