Are non-allergic drug reactions commonly documented as medication "allergies"? A national cohort of Veterans' admissions from 2000 to 2014.

PURPOSE: Adverse drug reactions (ADRs) including medication allergies are not well-described among large national cohorts. This study described the most common documented medication allergies and their reactions among a national cohort of Veterans Affairs (VA) inpatients.

METHODS: We evaluated inpatient admissions in any VA Medical Center from 1 January 2000 to 31 December 2014. Each admission was linked with allergy history preceding or upon admission. Individual drugs were aggregated into drug class category including: penicillins, sulfonamides, angiotensin converting enzyme (ACE) inhibitors, opiates, HMG-CoA reductase inhibitors ("statins") and non-steroidal anti-inflammatory inhibitors (NSAID). Results were reported in aggregate and over time.

RESULTS: Approximately ~10.8 million inpatient admissions occurred from 2000 to 2014. We found the most commonly reported allergy drug classes were penicillins (13%, n = 1 410 080), opiates (9.1%, n = 984 978), ACE inhibitors (5.7%, n = 618 075) sulfonamides (5.1%, n = 558 653), NSAIDs (5.1%, n = 551 216) and statins (3.6%, n = 391 983). Several allergy histories increased over time including opiates (6.2 to 11.2%), ACE inhibitors (1.3 to 10.2%), statins (0.3 to 7.3%) and NSAIDs (3.9 to 6.0%). Rash was the most commonly documented reaction on reports for penicillins (25.5%, n = 371 825), sulfonamides (25.6%, n = 165 954) and NSAIDs (10.3%, n = 65 741). The most common reaction for opiates was nausea/vomiting (17.9%, n = 211 864), cough/coughing for ACE inhibitors (41.0%, n = 270 537) and muscle pain/myalgia for statins (34.1%, n = 186 565).

CONCLUSIONS: We report that penicillins and opiates are the most commonly documented drug allergies among VA inpatients, but other drug classes such as ACE inhibitors, statins and NSAIDs are becoming increasingly common. Clinicians also commonly document non-allergic ADRs in the allergy section such as cough or myalgia. Copyright © 2016 John Wiley & Sons, Ltd.