Abstract
Background
Adverse drug reactions (ADRs) are common in clinical practice, most of them presented only with mucocutaneous symptoms. Drug induced anaphylaxis is rare, but it is responsible for most deaths due to ADRs. The aim of this study was to evaluate drug induced anaphylaxis treated in an Allergy Outpatient Clinic of a University Hospital.
Methods
Retrospective analysis of medical records from patients who seek assistance because of ADR. We looked for clinical criteria for diagnosing anaphylaxis, as recommended in WAO Guidelines. Criteria were classified in numbers 1 to 3:1) Acute onset of an illness (minutes to several hours) with involvement of the skin-mucosal tissue and respiratory and/or cardiovascular compromise; 2) Two or more of the following that occur rapidly after exposure to a likely allergen: involvement of skin-mucosal tissue, respiratory, cardiovascular and/or gastrointestinal compromise; 3) Reduced blood pressure after exposure to known allergen for that patient. We analyzed patients gender and age, drugs involved in reactions and administration of epinephrin.
Results
We studied 806 patients with history of ADR, of whom 123 (15.3%) presented clinical criteria of anaphylaxis (mean age 39.0 year old, female 101). The first clinical criteria was found in 60.2% and the second one in 38.2%. Epinephrin was injected in only 42 patients (34.1%). Non-steroidal anti-inflammatory drugs (NSAIDs) were most commonly suspected culprit drugs involved in anaphylactic reactions, with 59 patients (47.9%), followed by 40 patients with perioperative anaphylaxis (32.5%), 6 cases due to local anesthetics (4.9%) and 4 to antibiotics (3.2%). Between perioperative anaphylaxis, latex was involved in 10 reactions and neuromuscular blocking agents in 3.
Conclusions
We found a high prevalence of anaphylaxis, probably because patients with severe ADRs tend to be followed in university hospitals. Nevertheless, anaphylaxis is underdiagnosed in emergency departments, as we observed less than 35% of patients with drug induced anaphylaxis were treated with epinephrin. NSAIDs are still the most common drugs involved in ADRs in Brazil, including severe reactions, as anaphylaxis. In our country, latex still is an important agent incriminated in perioperative anaphylaxis, but anaphylaxis due to antibiotics are less common than in other countries.