Drugs used to treat RA may cause death, disability, and diseases, especially if the treatment continues in the setting of undetected toxicity. Prevention of toxicity may be enhanced by pretreatment assessment of individual risk factors for toxicity and by careful patient and physician education about safe use of the drug. Patients and their physicians must be alert to the signs and symptoms of toxicity that should prompt discontinuation of the drug and physician reassessment. Some drug toxicity may be discovered by appropriate laboratory monitoring before serious problems become clinically apparent. The 3 major drug categories for the treatment of RA are the NSAIDs, DMARDs, and glucocorticoids. Most NSAIDs have common GI and renal toxicity that may be averted by careful patient selection and administration of the drug. The individual DMARDs have specific toxicities for which monitoring protocols have been developed. The serious side effects of systemic glucocorticoids are largely related to dose and duration of treatment. The recommendations summarized in Table 1 are for basic monitoring in patients with uncomplicated RA. Additional monitoring may be appropriate for patients with comorbid disease, concurrent medication, or other risk factors.