Linezolid has been associated with reversible myelosuppression. Clinical trial data were evaluated for anemia, thrombocytopenia, and neutropenia. Thrombocytopenia and a slight increased risk for anemia were evident at >2 weeks of linezolid treatment. Hematologic abnormalities were consistent with mild, reversible, duration-dependent myelosuppression. Appropriate monitoring is warranted with linezolid use.

Although the pathophysiologic pathway leading to the development of AHS is unknown, it probably involves an immunologic mechanism following allopurinol accumulation in patients with poor renal function. Our findings suggest that the accepted diagnostic criteria for AHS may be too broad, and we recommend the application of more restrictive criteria. There is no effective treatment for AHS. The use of allopurinol only for accepted indications and in dosages adjusted for a patient's renal function may be the only means of minimizing the incidence of AHS.

Systemic use of immunosuppressant agents increases the risk of lymphoma in transplantation. We performed a nested case-control study in the PharMetrics database to evaluate the association between topical immunosuppressants and lymphoma in a cohort of patients with atopic dermatitis. We identified cases of lymphoma and randomly selected four controls for each case, matched by length of follow-up. We used conditional logistic regression to calculate odds ratio (OR) and 95% confidence intervals (CIs) of the association between topical immunosuppressants and lymphoma. Two hundred and ninety-four cases of lymphoma occurred in 293,253 patients, 81 in patients younger than 20 years. The adjusted analysis yielded the following OR (95%CI) for: severity (OR 2.4; 95% CI 1.5-3.8), oral steroids 1.5 (1.0-2.4), "super potent" topical steroids 1.2 (0.8-1.8) , "low potency" topical steroids OR 1.1 (0.7-1.6); pimecrolimus 0.8(0.4-1.6), tacrolimus OR 0.8 (0.4-1.7), and concomitant topical steroids, pimecrolimus, and tacrolimus 1.0 (0.3-4.1). We did not find an increased risk of lymphoma in patients treated with topical calcineurin inhibitors. It is difficult to disentangle the effects of severity of disease on outcome versus the true effects of drugs. However, in the adjusted analysis, severity of AD was the main factor associated with an increased risk of lymphoma.

Clozapine (Clozaril), a tricyclic dibenzodiazepine, causes fewer extrapyramidal side effects than do other antipsychotic drugs. Because it can induce agranulocytosis, however, clozapine is indicated only for schizophrenia that is not responsive to other therapies. To describe the drug's effects on mortality, we compared rates of various causes of death in 67,072 current and former clozapine users. We linked data from a national registry of clozapine recipients to the National Death Index and Social Security Administration Death Master Files, obtained death certificates, and calculated mortality rates for underlying causes of death using standardization to adjust for age, sex, and race. During 1991-1993, there were 396 deaths in 85,399 person-years for patients ages 10-54 years. Mortality was lower during current clozapine use than during periods of non-use. Mortality from suicide was decreased in current clozapine users by comparison with past users [rate ratio (RR) = 0.17; 95% confidence interval (CI) = 0.10-0.30]. During clozapine use, there were elevations in mortality rates for less common causes of death, including pulmonary embolism (RR for current exposure compared with past clozapine use = 5.2) and respiratory disorders (RR = 2.9). Clozapine appears to reduce mortality in severe schizophrenics, mostly by decreasing suicide rates.