Antimicrobial prophylaxis can decrease the incidence of postoperative surgical site infection after some procedures. Since the last Medical Letter article on this subject, consensus guidelines have been published. Recommendations for prophylaxis in specific surgical procedures are listed in Table 1.

The CDC recently reported that fluoroquinoloneresistant strains of Neisseria meningitidis have been detected for the first time in the US in an area around the border of North Dakota and Minnesota (CDC. MMWR, Feb 22, 2008). These isolates were all serogroup B, for which meningococcal vaccines (Med Lett Drugs Ther 2005; 47:29) do not offer protection. Since many laboratories do not test N. meningitidis for antimicrobial susceptibility, it is possible that such resistance is more widespread. A single oral dose of ciprofloxacin (Cipro, and others) 500 mg has been used for prophylaxis after close...

Since 2007, antimicrobial prophylaxis for dental procedures has been recommended to prevent viridans group streptococcal infective endocarditis only for patients at highest risk of an adverse outcome. Limiting use to such patients does not appear to have led to an increased incidence of infective endocarditis or increased mortality due to infective endocarditis.

The FDA has approved letermovir (Prevymis – Merck), a cytomegalovirus (CMV) DNA terminase complex inhibitor, for prophylaxis of CMV infection and disease in CMV-seropositive adult recipients of an allogeneic hematopoietic cell transplant (HCT). Letermovir is the first CMV DNA terminase complex inhibitor to be approved in the US and the only drug specifically indicated for CMV prophylaxis in HCT patients. It is not approved for treatment of CMV infection.

The FDA has approved emicizumab-kxwh (Hemlibra – Genentech), a subcutaneously injected, factor IXa- and X-directed antibody, for routine prophylaxis to prevent or reduce bleeding episodes in patients with hemophilia A. Emicizumab is not recommended for treatment of bleeding.

Some readers have asked why the June 2009 issue of Treatment Guidelines (Antimicrobial Prophylaxis for Surgery) did not recommend use of ertapenem (Invanz) for prevention of infection after elective colorectal surgery. Ertapenem is a broad-spectrum carbapenem that has been approved for such use by the FDA. Medical Letter consultants do not recommend use of broad-spectrum drugs such as ertapenem, third-generation cephalosporins such as cefotaxime (Claforan), ceftriaxone (Rocephin), cefoperazone (Cefobid), ceftazidime (Fortaz, and others) or ceftizoxime (Cefizox), or fourth-generation...

Many physicians believe that antimicrobial prophylaxis before procedures that may cause transient bacteremia can prevent endocarditis and prosthetic joint infection in patients at increased risk for these disorders. The effectiveness of this common practice has never been established by controlled trials in humans.

The CDC has issued a recommendation for use of a single dose of doxycycline for post-exposure prophylaxis (PEP) of bacterial sexually transmitted infections (STIs), specifically syphilis, chlamydia, and gonorrhea, in men who have sex with men (MSM) and transgender women (TGW) who had a bacterial STI within the previous 12 months.

The oral polymerase acidic endonuclease inhibitor baloxavir marboxil (Xofluza — Genentech) is now FDAapproved for post-exposure prophylaxis of influenza in patients ≥12 years old. Baloxavir was approved for treatment of acute uncomplicated influenza in patients ≥12 years old in 2018.1 Two neuraminidase inhibitors are FDA-approved for prophylaxis of influenza: oseltamivir (Tamiflu, and generics) in patients ≥1 year old, and zanamivir (Relenza) in patients ≥5 years old.2 Unlike oseltamivir and zanamivir, baloxavir is not FDA-approved for pre-exposure prophylaxis of...

The US manufacturer of varicella zoster immune globulin (VZIG; Massachusetts Public Health Biologic Laboratories, Boston, MA) recently discontinued its production. A Canadian formulation, VariZIG (Varicella Zoster Immune Globulin [Human] - Cangene Corporation, Winnipeg) is now available in the US under an investigational new drug application expanded access protocol.