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.

Mild to moderate plaque psoriasis can be treated with topical drugs and phototherapy. Patients with moderate to severe disease generally require systemic therapy. Guidelines for the treatment of psoriasis with topical therapy, phototherapy, and systemic drugs have recently been published.

Overweight is generally defined as a body mass index (BMI) between 25 and 29.9 kg/m2 in adults. A BMI ≥30 is considered obese (criteria differ slightly in Asian patients). In patients with an elevated BMI, a 5-10% reduction in weight has been associated with a reduction in the risk of developing type 2 diabetes, hypertension, and dyslipidemia. Diet, exercise, and behavior modification are the traditional methods for losing weight, but they are often inadequate; the American College of Cardiology no longer recommends that all patients try lifestyle modification alone before adding...

Psoriatic arthritis is a chronic inflammatory arthropathy associated with psoriasis. A recent review found that about 20% of patients with psoriasis have psoriatic arthritis. Updated guidelines for treatment of psoriatic arthritis have recently been published.

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...

Anticoagulants are the drugs of choice for treatment and prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE), collectively referred to as venous thromboembolism (VTE). US guidelines for treatment of VTE were updated in 2020 and 2021.

Primary hypothyroidism is usually the result of Hashimoto's thyroiditis, thyroidectomy for hyperthyroidism, goiter or cancer, or radioactive iodine therapy for hyperthyroidism.

Antiretroviral therapy is recommended for all HIV-infected patients, both to reduce the risk of disease progression and to prevent transmission of the virus to others. Various guidelines for treatment of HIV infection are available.

With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by parasites. The table in this document lists first-choice and alternative drugs for most parasitic infections.

The drugs of choice for treatment of viral infections (other than HIV) and their dosages are listed in Tables 1-6 on the pages that follow. Some of the indications and dosages recommended here have not been approved by the FDA. Vaccines used for the prevention of viral infections are discussed elsewhere.