Adverse drug reactions in patients attending in emergency service

Abstract

Objective: Describing adverse drug reactions (ADR) and analyzing the factors associated with their appearance in patients attending two hospitals' emergency services. Methods: Descriptive, medicine-surveillance study of people consulting the emergency service at the Rosales hospital and the basic total health attention unit in Pereira, Colombia, between July and September 2005 for any symptom related to taking medicine. Naranjo's Adverse Drug Reaction probability scale was used. Results: A total of 91 patients were found; 62,6 % were women having an average age of 36,3 ± 22,4 (range 0-85). Antibiotics (24,2 %) NSAIDs (17,6 %), analgesics (9,9 %) and antidiabetic agents (8,8 %) were the most used drugs. 39,6 % of the patients only used one medicine; the average of drugs per patient was 2,4 ± 1,5. Self-medication was present in 25,3 %. The most common ADRs arose from urticaria (31,9 %), hypoglycaemia (8,8 %), gastritis (6,6 %), angioedema (5,5 %) and anaphylaxis (4,4 %). 13,2 % of ADRs were serious and 54,9 % were avoidable. 14,3 % of ADRs were classified as being definite and 75,8 % probable. Only 14,3 % of patients had a past history of ADR. The average cost of being attended was US$ 78,1 dollars. Analgesic use was associated with anaphylaxis, antibiotics with urticaria whilst NSAIDs was associated with gastritis and gastrointestinal bleeding, antidiabetic agents with hypoglycaemia, antipsychotic and antidepressants agents with neurological symptoms and warfarin with bleeding. Conclusions: The most important ADR-associated risk factors in patients attending emergency services were determined. Special care must be paid to patients using NSAIDs, warfarin, metoclopramide, metamizole, antipsychotic and antidepressants agents, antidiabetic agents and antibiotics, having a past history of ADR, being more than 55 years old and presenting urticaria, digestive and/or neurological symptoms.