How does the doctor decide what to write on the prescription pad? iStockphoto.com hide caption

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The Centers for Disease Control and Prevention says doctors should prescribe Truvada, a once-a-day pill for HIV, to help prevent infections in IV drug users. Jeff Chiu/AP hide caption

itoggle caption Jeff Chiu/AP

Expensive prescriptions drugs can stretch people's finances, even if they have insurance. iStockphoto.com hide caption

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Prescriptions for testosterone medications, such as Testim and AndroGel, to men 40 and older rose threefold over the decade ending in 2011 MICHAEL BRYANT/MCT/Landov hide caption

itoggle caption MICHAEL BRYANT/MCT/Landov

Popular prescription drugs like statins are causing more childhood poisonings. Matt Rourke/ASSOCIATED PRESS hide caption

itoggle caption Matt Rourke/ASSOCIATED PRESS

If you're interested in buying Viagra, Pfizer, the drug's maker, will now sell it to you from its official website. William Vazquez/AP hide caption

itoggle caption William Vazquez/AP

Seniors in the Southeast were much more likely to be prescribed more than one high-risk medications in 2009. Danya Qato and Amal Trivedi/Alpert Medical School, Brown University hide caption

itoggle caption Danya Qato and Amal Trivedi/Alpert Medical School, Brown University

Dr. Sawen's Magic Nervine Pills contained calcium, iron, copper and potassium. Despite advertising claiming they were free of lead and mercury, both elements were found in the pills. Courtesy of Mark Benvenuto hide caption

itoggle caption Courtesy of Mark Benvenuto

Otolaryngologist Sandra Lin uses under-the-tongue drops to treat patients with allergies at Johns Hopkins in Baltimore. Courtesy of Keith Weller/Johns Hopkins Medicine hide caption

itoggle caption Courtesy of Keith Weller/Johns Hopkins Medicine

Plan B is one of two emergency contraceptives available in the U.S. UPI/Landov hide caption

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