Drug hypersensitivity in Phramongkutklao Hospital.

OBJECTIVE To evaluate the prevalence of drug hypersensitivity, clinical manifestations, type of drugs involved, severity, and patients demographic data. STUDY DESIGN A cross-sectional descriptive study. MATERIAL AND METHOD The study was performed from January 1st, 2008 to December 31th, 2008 at Phramongkutklao Hospital. Data were collected from Pharmaceutical Department, Dermatology Unit, Department of Medicine including adverse events reported by pharmacists. All records of in-patients and out-patients including gender, age, causative drugs, type of drug hypersensitivity and severity of hypersensitivity were collected. RESULTS A total of 140 patients who had drug hypersensitivity were recorded. The most common drug hypersensitivity was due to antimicrobial agents which penicillin group was the most frequently involved. Of 61 patients (43.57%), 27 (19.28%) received anti-inflammatory and muscle relaxant drugs and 18 (12.85%) had drugs acting on the central nervous system. The most common manifestration of drug allergy was maculopapular rash (34.99%), followed by nonspecific erythrematous rash (16.42%), fixed drug eruption (9.28%) and Stevens-Johnson syndrome (8.57%), respectively. Majority (80.71%) of drug hypersensitivity was mild in severity. Moderate, severe and lethal hypersensitivity accounted for 8.51%, 10.0%, 0.71% respectively. Female were 51.77% while 48.22% were male. The mean age was 47.0 years (ranged from 8-100 years). There were 57 (40.71%) patients over 50 years of age and 103 (73.57%) patients had taken more than one medication. CONCLUSION Antimicrobial agents were the common cause while maculopapular rash was the most frequent clinical manifestation of drug hypersensitivity.