According to the World Health Organization (WHO), unwanted effects are classified according to their frequency of development as follows: very often (> 1/10), often (> 1/100, <1/10), infrequently (> 1/1000, < 1/100), rarely (> 1/10000, <1/1000) and very rarely (<1/10000); frequency is unknown (the frequency of occurrence of phenomena can not be determined on the basis of available data).
Allergic reactions
infrequently: pruritus, rash, exanthema, urticaria; angioedema, decreased blood pressure, tachycardia;
rarely: anaphylactic reactions up to anaphylactic shock, Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell's syndrome).
From the respiratory system
rarely: shortness of breath, bronchospasm (mainly in patients with hyperreactivity of the bronchi in bronchial asthma).
From the sense organs
infrequently: noise in ears.
From the gastrointestinal tract
infrequently: stomatitis, abdominal pain, nausea, vomiting, diarrhea, indigestion.
Other
rarely: headache, fever, isolated reports of the development of bleeding due to the presence of a hypersensitivity reaction, a decrease in platelet aggregation.