Validity and accuracy of self-reported drug allergies

Grant, Elzaan

Title: Validity and accuracy of self-reported drug allergies
Creator: Grant, Elzaan
Subject: Drug allergy
Subject: Medical history taking
Date Issued: 2015
Date: 2015
Type: Thesis
Type: Masters
Type: MPharm
Identifier: http://hdl.handle.net/10948/3295
Identifier: vital:20421
Description: Purpose: Pharmacists must ensure the safe and effective use of medication, but often have only the documented patient history to guide assessment of therapy. There is a lack of information on the incidence of claimed drug allergies or the validity of these self-reported drug allergies in the South African population. Mislabelling of patients as being allergic to medication often deprives them of important therapeutic drugs and alternative agents may be more dangerous, less effective and more costly (Hung et al., 1994). The aim of the research was therefore to determine the incidence of drug allergies in patients admitted to a private hospital and to assess the validity of these self-reported drug allergies. Methods: A descriptive, non-experimental study design was used. Data was collected using a concurrent, cross-sectional approach and collected from patients admitted to hospital using Medical Chart Reviews and researcher-led, questionnaire based interviews. During the seven month sampling period, 693 patients were identified with one or more self-reported drug allergies. A subset of 99 patients (14.2%) consented to a researcher-led interview. The allergies were assigned to one of three groups based on the history: (i) High probability: signs and symptoms typical of an immunological reaction. (ii) Low probability: signs and symptoms of the reaction were predictable reactions or side effects of the drug. (iii) Unknown status: no information concerning the reaction history was available. Results: A total of 953 allergies were identified in the 693 patients, with a ratio of drug allergy to patient of 1.4:1. The majority of claimed allergies were to penicillin (39.2%), opioid analgesics (17.6%), other antimicrobials, including co-trimoxazole (13.5%), NSAIDs (9.9%) and unspecified “sulphur” allergy (8.7%). Descriptions of the “allergic” reactions were only recorded on 8.9% (62, n=693) of the reviewed charts. Only 56.5% (35, n=62) of the symptoms recorded as “allergy” were indicative of the event being allergic or immunological in nature. In total, 1.3% (9, n=693) of the patients with a self-reported allergy received the allergen while in hospital. In three cases this was the result of a pharmacist overlooking the recorded allergy, and dispensing the allergen to the patient. A total of 118 allergies were identified in the 99 interviewed patients, with a ratio of drug allergy to patient of 1.2:1. Inaccurate allergy history was found in 9.1% (9, n=99) of the interviewed patients. Overall, the majority of self-reported drug allergies (67.8%) had a “high probability” of being a true drug allergy. Allergies that were assigned into the high probability group were: penicillin (74.1%), co-trimoxazole (91.7%), NSAID‟s (55.6%) and 75.0% of opioids. Conclusion: In summary, the validity of self-reported drug allergies need to be determined before excluding medication from a patient‟s treatment options. Detailed descriptions can assist in the evaluation of self-reported allergies which would be advantageous to both prescribers and patients. Pharmacists need to play a bigger role in ensuring accurate documentation of drug allergy history, with detailed descriptions, in order to ensure safe and effective drug use within the hospital environment.
Format: xii, 157 leaves
Format: pdf
Publisher: Nelson Mandela Metropolitan University
Publisher: Faculty of Health Sciences
Language: English
Rights: Nelson Mandela Metropolitan University

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