Epidemiology of Adverse Cutaneous Drug Reactions. A Prospective

Study in Hospitalized Patients

Amparo Herna´ndez-Salazar,a Samuel Ponce-de-Leo´n Rosales,b Sigfrido Rangel-Frausto,b
Elia Criollo,c Carla Archer-Dubon,a and Roc?´o Orozco-Topetea
aDermatology Department, bSubdivision of Hospital Epidemiology and Patient Care Quality Control, cPharmacy Department,
Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubira´n, Mexico City, Mexico
Received for publication June 2, 2005; accepted March 20, 2006 (ARCMED-D-05-00211).

Background. Drug reactions are commonly present in the skin; however, their frequency
in our setting is unknown.

Methods. A 10-month prospective cohort study including all hospitalized patients was
designed. Those with adverse cutaneous drug reactions (ACDR) were clinically identified.

Results. Thirty five drug reactions (prevalence of 0.7%) were seen among 4785 (2713 females,
2072 males) discharged patients. According to Begaud’s imputability criteria, the
reactions were most likely attributed to a drug in 4.87%, likely in 41.46% and possible in
53.65%. The most commonly seen dermatoses were morbilliform rash 51.2%, urticaria
12.2% and erythema multiforme 4.9%. Drugs most frequently associated with ACDR
were amoxicillin clavulanate (8), amphotericin B (2) and metamizole (4). Expressed as
risk by 1000 day-doses (Dd: the risk a patient has of developing an ACDR after receiving
1 day of treatment with the drug): amoxicillin clavulanate Dd 7.7, amphotericin B Dd 4.8
and metamizole Dd 3.7. Immunosuppressed patients were most frequently affected. Notably,
patients with systemic lupus erythematosus (SLE) had a 4.68 higher risk (CI 95%
1.794e12.186 p !0.001) of developing an ACDR. AIDS patients showed a risk of 8.68
(CI 95% 2.18e33.19 p !0.001). Non-Hodgkin’s lymphoma patients also had an increased
risk of developing an ACDR. Six of the 35 identified cases were patients who
had been hospitalized due to a severe drug reaction (1.3/1000 patients); one died from
complications directly related to the ACDR, representing a 16.6% mortality rate among
those admitted for an ACDR and 0.02% among the global mortality.

Conclusions. We have a low prevalence of drug reactions compared to data reported in
the literature. Pharmacovigilance with special attention to immunosuppressed SLE or
AIDS patients is stressed. _ 2006 IMSS. Published by Elsevier Inc.