Smoking tobacco remains the primary preventable cause of death in the US. Smoking cessation often requires both pharmacotherapy and behavioral support.

A variety of cancer chemotherapy drugs are used, mostly in combination, for treatment of locally advanced and metastatic esophageal, gastric and colorectal cancers. The mechanism of action, indications and adverse effects of some of these drugs are discussed in thei article.

Alzheimer's disease (AD) is the most common cause of dementia, but cognitive decline is also associated with other neurological conditions such as Parkinson's disease, dementia with Lewy bodies, vascular dementia, and frontotemporal dementia.

The drugs of choice for treatment of common cardiac arrhythmias are listed in Tables 1 and 2. Some drugs are recommended for indications that have not been approved by the FDA.

Use of screening tests to identify cancers before they cause symptoms can lead to earlier therapy and may improve outcomes. Screening tests for some common cancers are reviewed below.

Persons planning to travel outside the US should be up to date on routine vaccines and, depending on their destination, duration of travel, and planned activities, may also receive certain travel-specific vaccines. Tickborne encephalitis and dengue vaccines, which are not available in the US, are reviewed in a separate article available online. Detailed advice for travel to specific destinations is available from the Centers for Disease Control and Prevention (CDC) at www.cdc.gov/travel/destinations/list. Recommendations for administration of vaccines as part of routine...

Attention-deficit/hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder that has been diagnosed in up to 10% of school-age children in the US and frequently persists into adulthood. A study in a large Danish cohort found that ADHD was associated with higher mortality rates in children, adolescents, and adults, mainly due to accidents. Pharmacologic treatment of ADHD in children has been reported to decrease the risk of substance abuse in adolescents, and use of ADHD medications in adults has been associated with a reduced risk of serious traffic accidents and...

Anxiety disorders (generalized anxiety disorder, panic disorder, social anxiety disorder, and various phobias) are the most common form of psychiatric illness. They can be treated effectively with cognitive behavioral therapy (CBT) and/or pharmacotherapy.

American College of Cardiology/American Heart Association (ACC/AHA) guidelines for treatment of hypertension were last published in 2018. Treatment of hypertensive urgencies and emergencies is not discussed here.

The tables in this article list drugs used for treatment of cancer in the USA and Canada and their major adverse effects. The choice of drugs in Table I is based on the opinions of Medical Letter consultants. Some drugs are listed for indications for which they have not been approved by the US Food and Drug Administration. In some cases, such as elderly patients or those with many co-morbid illnesses, the regimen of choice might not be suitable. For many of the cancers listed, surgery and/or radiation therapy may be the treatment of choice or may also be part of the management. Anticancer...