Tizanidine (Zanaflex - Athena Neurosciences) has been approved by the US Food and Drug Administration for oral treatment of increased muscle tone associated with spasticity. It has been available in Europe and Japan for 12 years as a short-term muscle relaxant.

Bupropion hydrochloride, currently available as an antidepressant (Wellbutrin - Medical Letter, 31:97, 1989; Wellbutrin SR), is now being marketed in a sustainedrelease formulation as Zyban (Glaxo Wellcome) for use as an aid in smoking cessation.

Clopidogrel bisulfate (Plavix - Bristol-Myers Squibb/Sanofi), a new thienopyridine antiplatelet agent similar to ticlopidine (Ticlid - Medical Letter, 34:65, 1992), has been approved by the US Food and Drug Administration (FDA) for secondary prevention of myocardial infarction, stroke and other vascular events.

The FDA has approved the partial opioid agonist buprenorphine in a transdermal formulation (Butrans – Purdue) for treatment of moderate to severe chronic pain. Buprenorphine has been available in the US for years in parenteral formulations for pain and in sublingual tablets for opioid dependence.1 Transdermal buprenorphine has been available in Europe for several years.2

The FDA has approved abiraterone acetate (Zytiga – Centocor Ortho Biotech) for oral treatment, in combination with prednisone, of metastatic castration-resistant prostate cancer in patients previously treated with docetaxel (Taxotere, and others). It is the first oral drug approved for this indication. Zytiga will compete with cabazitaxel (Jevtana) and sipuleucel-T (Provenge).

The FDA has approved vemurafenib (Zelboraf – Genentech), a kinase inhibitor, for treatment of unresectable or metastatic melanoma with the BRAF V600E mutation, which is found in 30-60% of melanomas. An FDA-approved test can detect the mutation in DNA from melanoma tissue.

The FDA has approved an oral liquid formulation of glycerol phenylbutyrate (Ravicti – Hyperion) for chronic management of patients ≥2 years old with urea cycle disorders that cannot be adequately managed by a protein- restricted diet. Sodium phenylbutyrate (Buphenyl, and generics), another oral drug approved by the FDA for this indication, has a bitter taste. The new product, which contains no sodium, has little or no taste. Either drug must be used in addition to a protein-restricted diet and, if needed, dietary supplementation with amino acids and other nutrients.

The FDA has granted regular approval to the oral kinase inhibitor tepotinib (Tepmetko – EMD Serono) for treatment of adults with metastatic non-small cell lung cancer (NSCLC) harboring mesenchymal-epithelial transition (MET) exon 14 skipping alterations. MET exon 14 skipping mutations occur in 3-4% of NSCLC cases and are associated with advanced disease and a poor prognosis. Tepotinib received accelerated approval for the same indication in 2021 based on initial overall response rates and duration of response.

Leflunomide (Arava - Hoechst Marion Roussel), which inhibits pyrimidine synthesis, and etanercept (Enbrel - Immunex/Wyeth-Ayerst), which blocks the action of tumor necrosis factor (TNF), have been approved by the FDA for treatment of rheumatoid arthritis. A third drug, infliximab (Remicade - Centocor), which also blocks TNF and has been used to treat rheumatoid arthritis, was approved earlier for treatment of Crohn's disease. Its use in Crohn's disease will be reviewed in a future issue.

Amprenavir is the fifth protease inhibitor to become available for treatment of HIV infection. It was approved by the FDA for use with other drugs in the treatment of HIV-infected adults and children at least four years old.