Sodium phenylbutyrate, an "orphan drug,"has recently been marketed for the treatment of patients with urea cycle disorders caused by a deficiency in one of the following hepatic enzymes: carbamyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). Urea cycle disorders are rare; they occur in one of every 10,000 births.

Rifapentine, a long-acting analog of rifampin developed in the 1960's, has received an accelerated approval from the FDA for oral use, with at least one other drug, in the treatment of pulmonary tuberculosis.

The FDA has approved enzalutamide (en za loo’ ta mide; Xtandi – Astellas/Medivation) for oral treatment of metastatic castration-resistant prostate cancer in patients previously treated with docetaxel (Taxotere, and generics). It is the second oral drug approved for this indication; abiraterone acetate (Zytiga), which is also approved for first-line use, was the first. Cabazitaxel (Jevtana), which is given parenterally, has a similar indication.

The oral kinase inhibitor alpelisib (Vijoice – Novartis) has been approved by the FDA for treatment of patients ≥2 years old with severe manifestations of PIK3CA-related overgrowth spectrum (PROS) who require systemic treatment. Alpelisib is the first drug to be approved in the US for this indication. It was also approved in 2019 as Piqray for use in combination with fulvestrant for treatment of certain types of breast cancer.

The FDA has approved Zunveyl (Alpha Cognition), a delayed-release formulation of the prodrug benzgalantamine, for treatment of mild to moderate dementia of Alzheimer's disease (AD). Immediate- and extended-release formulations of the acetylcholinesterase inhibitor galantamine have been available in the US for years for treatment of AD.

Two types of oral contraceptives are available in the USA: combination oral contraceptives that contain both an estrogen and a progestin, and progestin-only contraceptives, or "mini-pills."Used as directed, all oral contraceptives marketed in the USA are similarly effective in preventing pregnancy.

Solifenacin succinate (VESIcare - Yamanouchi and GlaxoSmithKline) and darifenacin hydrobromide (Enablex - Novartis) have been approved by the FDA for oral treatment of overactive bladder.

The FDA has approved lumateperone (Caplyta — Intracellular Therapies), an oral second-generation antipsychotic, for once-daily treatment of schizophrenia in adults. It is the 13th second-generation antipsychotic drug to be approved by the FDA for this indication.

The FDA has approved vonoprazan, a potassium-competitive acid blocker, copackaged with amoxicillin (Voquezna Dual Pak – Phathom) and with amoxicillin and clarithromycin (Voquezna Triple Pak) for treatment of Helicobacter pylori infection in adults. Vonoprazan is the first potassium-competitive acid blocker to be approved in the US. It has been available in Japan for treatment of various acid-related disorders since 2014. Vonoprazan is not available alone in the US.

The drugs of choice for treatment of fungal infections are listed in the table that begins on page 62. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines for some of these infections are available online from the Infectious Diseases Society of America (www.idsociety.org).