Drug allergy assessment at a university hospital and clinic.

The accuracy of drug allergies reported in patients' medical records and the cost-effectiveness of pharmacist interviews to clarify these reports were studied. Fourteen pharmacists interviewed hospital and clinical patients about reported allergies and noted their assessments in the patients' charts. The patient's physician was notified of discrepancies between previous allergy documentation and the pharmacist's assessment. The pharmacy resident re-interviewed a convenience sample of the patients to determine consistency among the pharmacists. The reported reactions were classified as true allergies, severe adverse effects, or vague reactions (drug should be avoided); drug intolerance and mild or moderate adverse effects; excessive pharmacologic effects; or no reaction experienced. The medication profile for each patient was reviewed after discharge to identify the pharmacists' prevention of adverse effects or allergic reactions; cost avoidance was then estimated. The pharmacists assessed 347 reports of allergies in 195 patients. Anti-infective agents accounted for 53% of the stated allergies, followed by narcotics (18%), psychotropic medications (7%), nonsteroidal anti-inflammatory drugs (6%), cardiovascular medications (5%), and others (11%). For more than 80% of the reports of allergies to beta-lactam antibiotics and sulfonamides, pharmacists either found or could not rule out true allergies; this was the case for only 31% of reported allergies to narcotics. Nine percent of patients who reported allergy to a beta-lactam or sulfonamide had never experienced a reaction to the drug. Pharmacists intervened in four cases to prevent adverse reactions and a total of 4.4 additional hospital days, and in five instances the use of a less suitable or more expensive drug was avoided. Pharmacists found a large discrepancy between reported allergies and true allergies and helped prevent uses of drugs that could have prolonged patients' hospital stay.