The FDA has approved baloxavir marboxil (Xofluza – Shionogi/Genentech), the first polymerase acidic (PA) endonuclease inhibitor, for single-dose, oral treatment of acute uncomplicated influenza in patients ≥12 years old. Baloxavir is the first drug with a new mechanism of action to be approved for treatment of influenza in almost 20 years.

Fluoxetine (Prozac - Dista), a phenylpropylamide, is the first serotonin-reuptake blocker introduced in the USA for treatment of . It is being promoted as causing fewer adverse effects than other antidepressants. Claims of greater safety and patient tolerability have often been made for new non-tricyclic antidepressants in recent years, but unpredicted adverse effects have emerged with widespread use, including priapism with trazodone (Desyrel - Medical Letter, 26:35, 1984) and fatal hemolytic anemia with nomifensine (Merital - Medical Letter, 27:73, 1985).

In a study of the interaction between alcohol and the calcium-channel blocker felodipine (Plendil), the grapefruit juice vehicle for the alcohol appeared to increase felodipine plasma concentrations. Subsequent studies have found that grapefruit juice increases plasma concentrations of several calcium-channel blockers and of some other drugs as well (DG Bailey et al, Clin Pharmacokinet, 26:91, 1994).

Ceftibuten (Cedax - Schering), an oral cephalosporin similar to cefixime (Suprax - Medical Letter, 31:73, 1989), has been approved by the US Food and Drug Administration (FDA) for treatment of acute otitis media, pharyngitis or tonsillitis, and for acute bacterial exacerbations of chronic bronchitis.

The antiestrogen toremifene (Fareston - Schering) and the selective aromatase inhibitor letrozole (Femara - Novartis) have been approved by the FDA for treatment of advanced breast cancer in postmenopausal women.

Many drugs, mostly azole derivatives, are marketed in the USA for topical treatment of vulvovaginal candidiasis. A single-dose, sustained-release formulation of butoconazole nitrate 2% cream (Gynazole 1) is the newest addition. Fluconazole (Diflucan) is approved for single-dose oral treatment.

Patients with lung cancer may be asking their physicians about gefitinib (ge fi' tye nib; ZD1839; Iressa -- AstraZeneca), because it has been the subject of positive coverage in the media. An inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, this oral drug has not been approved by the FDA, but is in clinical trials in the US for treatment of non-small cell lung cancer (NSCLC) and some other solid tumors. Iressa was recently approved in Japan, and is available from the manufacturer on a "compassionate-use" basis in the US (800-236-9933).

The heptavalent pneumococcal conjugate vaccine (Prevnar - Wyeth) previously approved by the FDA for prevention of invasive pneumococcal disease in infants and children (Medical Letter 2000; 42:25) has now also been approved for prevention of otitis media. Infants and young children have higher antibody responses to the heptavalent conjugate vaccine (PCV7) than to the older 23-valent pneumococcal polysaccharide vaccine (PPV23) used in adults and older children (D Murray and C Jackson, Mil Med 2002; 167:671).

Acetaminophen (paracetamol; Tylenol, and others) taken in overdosage can cause severe hepatic injury and death. Acetaminophen poisoning is treated with (N-)acetylcysteine. Available for many years in the US as a solution for inhalation therapy (Mucomyst, and others), it subsequently became available for oral use and was recently marketed in the US for intravenous (IV) use as Acetadote (Cumberland).

The FDA has approved ibalizumab-uiyk (Trogarzo – Theratechnologies/TaiMed), a CD4-directed monoclonal antibody, for IV treatment of multidrug-resistant HIV-1 (MDR-HIV) infection in heavily antiretroviral-experienced adults with treatment failure on their current regimen. Ibalizumab-uiyk is the first biologic drug to be approved by the FDA for treatment of HIV-1 infection.