Age, gender & co-morbidities as risk factors for drug-induced diseases.

Sir,

The study by Tandon and colleagues1 on drug-induced diseases (DIDs) is very interesting. However, we have some comments regarding this study. An important portion of the study population was geriatric patients (54%). Also, the number of females was significantly more than males (1.7 vs 1). As stated by Zopf et al2, advanced age and female gender were important risk factors for DIDs. So, these two factors might have significantly affected the results of this study.

As seen in Table I, there was a significant difference between the number of patients with single disease and co-morbid conditions (P<0.001). It would be important to know how many patient in this study had diabetes mellitus, chronic renal insufficiency, hepatic insufficiency or AIDS. Because, such co-morbidities cause secondary immune deficiencies and patients having these co-morbidities are more susceptible to adverse effects of immunosuppressive medications such as methotrexate, cyclophosphamide and corticosteroids3.