A reader has questioned why the label for the COX-2 selective NSAID celecoxib (Celebrex, and generics), which contains a sulfonamide moiety, states that it is contraindicated for use in patients with an allergy to sulfonamides, while the labels of some other sulfonamide drugs recommend either caution or no precautions at all. The concept of cross-reactivity among sulfonamide drugs, particularly between antibacterial and nonantibacterial sulfonamides, has been controversial for many years.

The FDA recently announced that it will require the labeling of all direct-acting antiviral drugs used for treatment of hepatitis C virus (HCV) infection to include a boxed warning about a risk of hepatitis B virus (HBV) reactivation associated with their use.1Twenty-four cases of HBV reactivation occurring during treatment with direct-acting antiviral drugs for HCV were identified from the FDA Adverse Event Reporting System and the medical literature.2-5 Before starting direct-acting antiviral treatment for HCV, some of these patients were hepatitis B surface antigen (HbsAG) positive and...

Modestly elevated C-reactive protein (CRP) concentrations have been associated with an increased risk of coronary heart disease. The recently published and heavily publicized results of the JUPITER trial will lead many patients to ask health care professionals whether they should have a CRP test to see if they should be taking a statin.

Diagnostic tests for human immunodeficiency virus (HIV) infection use four approaches: identification of antibodies to viral proteins, detection of viral antigens, detection of viral nucleic acids, and culturing the virus (CJ Schleupner in GL Mandell et al, eds, Principles and Practice of Infectious Diseases, 4th ed, New York:Churchill Livingstone, 1995, page 1253). In recent years, the FDA has approved the use of a 10- minute blood test, two home collection kits, and office tests that use urine and oral secretions to diagnose HIV infection. One home test, Confide (Johnson & Johnson), was...

View Expanded Table: Some Biologic Drugs and JAK Inhibitors for Rheumatoid Arthritis

Testing for HIV infection in the US typically has been a two-step process that requires patients to return for results. This review describes two rapid tests currently FDA-approved, OraQuick and Reveal. It includes a table with the cost and characteristics of each test (result time, device type, equipment needed, etc.).

The FDA has approved the nitrofuran antiprotozoal drug nifurtimox (Lampit – Bayer) for treatment of Chagas disease (American trypanosomiasis) in children who weigh ≥2.5 kg. Nifurtimox was previously available in the US only through a CDC-sponsored Investigational New Drug (IND) program.

Testing for drug use has become increasingly common, not only in health care, but also in drug rehabilitation, in the military, at the workplace, after accidents and in the criminal justice system. Performance-enhancing drugs such as anabolic steroids, growth hormone (Genotropin, and others) and erythropoietin (Procrit, Epogen) are not discussed here.

Lipoprotein associated phospholipase A₂ (Lp-PLA₂), an enzyme involved in the repair of oxidative damage to lipoproteins, causes release of inflammatory mediators associated with atherosclerosis. A new assay, PLAC (diaDexus, Inc.), is now available to measure Lp-PLA₂ levels. C-reactive protein (CRP), another inflammatory mediator, appears to be a biomarker for coronary disease (MH Shishehbor et al, Cleve Clin J Med 2003; 70:634). The role of Lp-PLA₂ testing in determining cardiovascular risk is less clear.

Natalizumab (Tysabri - Elan and Biogen) is a monoclonal antibody approved for induction and maintenance treatment of moderate to severe Crohn's disease (CD) refractory to conventional therapies and inhibitors of tumor necrosis factor (TNF). Initially approved in 2004 for the treatment of multiple sclerosis (MS), natalizumab was temporarily withdrawn from the market after 3 patients developed progressive multifocal leukoencephalopathy (PML). It is now available for treatment of both MS and CD through a restricted distribution program.