Medications can harm as well as heal. In cardiologist Marcum’s mind, medicines are the number-one cause of death in North America and possibly the world. Human error—by physicians, nurses, and pharmacists—plays a role. Misuse of medicines and mistakes by patients are also to blame. Slipups in manufacturing, distribution, and labeling of medications happen. Problems with prescription medications and over-the-counter drugs include incorrect doses, drug-drug interactions, inappropriate administration for improper conditions, and lack of monitoring for side effects. Opioid painkillers, chemotherapeutic agents, blood thinners, antiarrhythmic drugs, and steroids head Marcum’s list of the most dangerous medications. Nevertheless, he admits that many medicines are worth the risks they carry. He encourages patients to ask questions: What is the rationale for the prescription? What are specific risks and common side effects? Are there alternatives to the use of drug therapy? But the final two chapters are preachy as Marcum injects a heavy dose of religion and makes an astonishing assertion: “I consider the Bible to be the greatest health journal ever written.” —Tony Miksanek