Abstract Objective To provide information regarding the most important properties of the new therapeutic agents marketed in the second half of 2012. Data sources Product labeling, supplemented selectively with published studies and drug information reference sources. Data synthesis 13 new therapeutic agents were marketed in the United States during the second half of 2012, bringing the total for the year to 25. Six new agents are considered in this article (part 1 of a two-part series): elvitegravir/cobicistat, mirabegron, linaclotide, aclidinium bromide, tofacitinib citrate, and teriflunomide. Indications and information on dosage and administration for these agents are reviewed, as are the most important pharmacokinetic properties, drug interactions, and other precautions. Practical considerations for the use of these new agents are also discussed. When possible, the properties of the new drugs are compared with those of the older agents marketed for the same indications. Conclusion Elvitegravir is the second antiretroviral agent that acts as a HIV-1 integrase strand transfer inhibitor to be approved for the treatment of HIV infection, joining raltegravir. It is supplied in a combination formulation that also includes cobicistat, an agent that inhibits the metabolism of elvitegravir and prolongs its action, as well as the antiretroviral agents emtricitabine and tenofovir disoproxil fumarate. Mirabegron is a beta-3–adrenergic receptor agonist that is indicated for the treatment of overactive bladder and offers an alternative to the previously marketed anti- cholinergic agents (e.g., tolterodine) for this condition. Linaclotide joins lubiprostone as the only agents on the market for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation. Aclidinium bromide is administered by oral inhalation for the long-term maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease, and has properties that are most similar to those of tiotropium. Tofacitinib citrate has been approved for the treatment of patients with moderately to severely active rheumatoid arthritis who have had an inadequate response or intolerance to methotrexate. It is effective when administered orally and may be effective in some patients who have had an inadequate response with parenterally administered biologic antiarthritic agents such as adalimumab. Teriflunomide is the active metabolite of leflunomide and is administered orally for the treatment of patients with relapsing forms of multiple sclerosis.