Immediate-type hypersensitivity reactions due to antituberculosis drugs: a successful readministration protocol.

ABSTRACT

BACKGROUND: Little is known about drug hypersensitivity reactions from antituberculosis drugs. OBJECTIVE: To determine the frequency, risk factors, and characteristics of immediate-type hypersensitivity reactions from first-line antituberculosis drugs and to evaluate the usefulness of a readministration protocol for culprit drugs in this group of patients. METHODS: The study population consisted of patients with tuberculosis who were hospitalized and treated in the authors' hospital in 2011. Demographics and disease and treatment characteristics of patients with immediate-type hypersensitivity from antituberculosis drugs were compared with the other patients. Culprit drugs were readministered gradually according to a defined protocol to patients with immediate-type hypersensitivity. RESULTS: Tree hundred seventy-nine patients were included in the study. Eighteen immediate-type hypersensitivity reactions were detected in 13 patients (3.43%). The only identified risk factor was female sex (odds ratio 4.085). Isoniazid, rifampicin, pyrazinamide, and ethambutol were readministered in 11 patients and rifampicin was readministered in 2 patients, with 6- to 8-step protocols for each drug. Only in 2 patients did allergic reactions with rifampicin develop during the procedure. In these patients, after treatment and complete remission of allergic symptoms, the last tolerated dose was administered and the protocol was completed with the same adjustments. CONCLUSION: Immediate-type allergic reactions from antituberculosis drugs are not rare and not related to disease or treatment characteristics. The protocols used in this study provide a useful and safe method for readministration of culprit drugs to patients with antituberculosis drug hypersensitivity.