Drug allergies and quality of taken medican history in hospitalized patients

Introduction: Drug allergies may complicate choice of pharmacotherapy. In the case of an invalid of false-positive allergy history the patient may be exposed to second-line drugs that may present higher risk of side effects or increase cost of care.

Methods: Prospective analysis of health records of hospitalized patients followed by a structured interview with detailed history. Between 11/2018 and 4/2019 we examined 92 hospitalized patients at selected clinics of the University Hospital in Olomouc.

Results: The prevalence of drug allergies in our sample of hospitalized patients was 21.2%. In 92 patients we identified a total of 163 drug allergies (a mean of 1.8 allergy per patient). The most common manifestations were cutaneous (39% of reactions) and gastrointestinal (16%). Allergies to antimicrobial agents were most commonly reported (36%), followed by analgesics (16%), iodine (11%) and local anesthetics (7%). Betalactam antibiotics (55%) and sulfonamides (24%) were the most common antibiotics with reported allergies. In 10% of reported allergies a mismatch between the patients history and his documentation was identified. Approximately 18% of reactions were evaluated by the authors to be likely non-allergic adverse effects.

Conclusion: The prevalence of drug allergies among hospitalized patients is high, the most commonly reported drugs are antibiotics and analgesics. Validity of allergic history is key for rational and safe pharmacotherapy. Effort should be made to properly verify and document any drug allergies and intolerance.

Keywords: drug allergies, history, antibiotics, analgesics, rational pharmacotherapy, drug safety.